Volume 35 - Issue 2
Jalal Zakii; Mohammad Asoodar; Morteza Almasi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 1-12
Abstract
The erosion in dryland causes decrease in yield and soil quality, especially in slope lands with conventional tillage. To investigate the effects of tillage and planting methods in slope lands on erosion and yield of rain fed wheat, an experiment was conducted in 2007-2008 at Kermanshah Province. The ...
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The erosion in dryland causes decrease in yield and soil quality, especially in slope lands with conventional tillage. To investigate the effects of tillage and planting methods in slope lands on erosion and yield of rain fed wheat, an experiment was conducted in 2007-2008 at Kermanshah Province. The statistical design for this research was strip split plots in randomized complete blocks (RCB) with three replications. The dimension of each plot was 4×14 meters. Two slope levels (6-8 and 10-12 percent) were arranged in main plots, using three tillage systems (conventional, reduced and no tillage), and three planting methods (hand spreading, seeding by a grain drill parallel and perpendicular to slope) were arranged in sub-plots. Run off was shown 14020/19 L/hafor 6-8 percent slope while on 10 -12%, was measured to be about 15251/02 L/ha. Sediment was 10854 Kg/hafor 6-8% slope, and 12103 Kg/ha was found for 10 -12 percent slope. A significant (P<0.01) amount of grain yield was produced (1010 kg/ha) compared to moldboard plow and sweeps where chisel and sweep ploughs were applied. No tillage system produced 960 kg/ha grain yield, but it was not significantly different compared to other tillage treatments.
Volume 36 - Issue 1
Arezoo Mohammadi; Mohammad Bahmanyar; Mehdi Ghajar Sepanlou
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 1-11
Abstract
Salinity limited plant growth and will decrease the yield with decrease in solution osmotic pressure, nutrient imbalance and toxicity of some specific elements. Application of amendment materials such as gypsum and cattle manure can adjust the undesirable effects and increase the nutrient elements in ...
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Salinity limited plant growth and will decrease the yield with decrease in solution osmotic pressure, nutrient imbalance and toxicity of some specific elements. Application of amendment materials such as gypsum and cattle manure can adjust the undesirable effects and increase the nutrient elements in leaf and grain. In this regard a pot experiment was conducted during 2009 growing season based on split factorial with four replications in complete randomize design. In this experiment the main factor was inclusive different level of salinity in irrigation water {0, 3, 6, 9 and 12 dS/m as NaCl and CaCl2 (1:1 w/w)} and subsidiary factors were inclusive gypsum (0, 15 and 30 ton/ha) and the cattle manure (0 and 30 ton/ha). The results showed that increasing the salinity content of irrigation water causes reduce the amount of phosphorus and increase nitrogen and potassium in wheat leaves. Also, with increasing in salinity of irrigation water the amounts of phosphorus and potassium in grain decreased and the amount of nitrogen in grain increased. Application of gypsum increased the amounts of the nitrogen, phosphorus and potassium 6.31, 10.89 and 14.82 percent in leaves and the amounts of the nitrogen, phosphorus and potassium 10.32, 10.84 and 3.45 percent in grain, respectively. Using manure at different salinity treatments was significant affecting on the amounts of nitrogen and phosphorus in leaves and phosphorus and potassium in grain. The highest amounts of nitrogen and phosphorus in leaves and grain were obtained using 15 and 30 tons of gypsum per ha while the highest amount of potassium in leaves and grain were obtained using 30 tons of gypsum per ha.
Volume 36 - Issue 2
Mahmoud Ghaseminejad Raeini; Mohammad Sheikh Davoodi; Morteza Almasi; Houshang Bahrami; Eskandar Zand; Khalil Alamisaeid
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 1-16
Abstract
In order to evaluate the effects of seed bed preparation, fertilization and weed control (after planting) methods on growth and corn yield in northern part of Khuzestan a field experiment was conducted as split blocks in a randomized complete block design with four replications during 2009 and 2010. ...
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In order to evaluate the effects of seed bed preparation, fertilization and weed control (after planting) methods on growth and corn yield in northern part of Khuzestan a field experiment was conducted as split blocks in a randomized complete block design with four replications during 2009 and 2010. Three seed bed preparations consisting of Makhar condition (wet seeding) + conventional tillage (plough + disk + leveler), makhar condition + reduced tillage (disk) and without makhar + reduced tillage were performed in horizontal plots. Two methods of fertilizing (Broadcast and Drill) as main factors and weed controlling methods (once using of field cultivator in four-leaf stage (20 cm height of plants), two times using rolling cultivator in four and seven-leaf stage (20, 40 cm height of plant), using two liters Nicosolforon herbicides when the plant produced 3 - 4 leaves, and checking treatments (weed free and weed infect) as the sub-factors were conducted in vertical plots. The results indicated that population and biomass dry weight of weeds were significantly (p< %5) affected by Makhar. Planting in without makhar soil, caused reduction in the population and weed weight (30% and 40%) in the 5th week. In all tillage methods, the effect of two times using rolling cultivator and chemical control on grain yield and biological yield was statistically similar. In fertilizer drill method, grain yield and biological yields, kernel in rows and rows in ear were significantly (P<%1) higher than broadcast method. The most grain and biological yield were obtained in combination of makhar condition and fertilizer drill (in treatment of makhar condition + reduced tillage, grain yield was 9003.25 kg/ha.). Two times using rolling cultivator reduced the population and weight of weeds significantly more than chemical control in farm with plenty of Bind weed. In all of the Broadcast fertilizer methods, chemical control treatment had more yield (16%), but in fertilizer drill method there was no significant difference between chemical and two times using of rolling cultivator treatments. It seems that in corn farms when broadcasting fertilizer method is used, the chemical control of weed due to higher yield (15%) is more effective; two cultivator weed control method is recommended if the distribution of fertilizer is used with drilling method. The highest grain yield (9183 kg/ha) was obtained from the combination of makhar, reduced tillage, fertilizer drilling method and two times using rolling cultivator.
Volume 37 - Issue 1
N. Mehrab; M. Chorom; S. Hojati
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 1-11
Abstract
To evaluate the effect of two types of soil textures and zeolite enriched with ammonium on growth characteristics of wheat and water use efficiency, a factorial experiment based on a completely randomized design with three replications in greenhouse condition was conducted at Shaid Chamran University ...
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To evaluate the effect of two types of soil textures and zeolite enriched with ammonium on growth characteristics of wheat and water use efficiency, a factorial experiment based on a completely randomized design with three replications in greenhouse condition was conducted at Shaid Chamran University in the autumn of 2011. Treatments were 5% and 10% of the raw zeolite, 5% and 10% zeolite enriched with ammonium, fertilizer treatment (100 kg ha-1) and soil textures were clay loam and sandy loam. The results showed that the soil texture significantly affected the growth characteristics of wheat and water use efficiency (P<0.01). The plant nitrogen percentage, 1000-seed weight and seed yield were higher in sandy loam soil than in clay loam. Water use efficiency in sandy loam, was more than clay loam. None of the zeolite treatments had a significant effect on water use efficiency. The highest percentage of plant nitrogen fertilizer plants treated with ammonium-rich zeolite and 10%, respectively. The highest percentage of plant nitrogen was observed in chemical fertilizer treatment and 10% NH4+-zeolite and the highest seed yield was obtained in 10% NH4+-zeolite treatment. The highest C/N ratio was measured in treated with 10% raw zeolite in a sandy loam soil. Therefore, the application of ammonium zeolite enriched can be improved wheat growth characteristics and using less chemical fertilizer and thereby also saving on fertilizers helped to reduce environmental pollution.
Volume 37 - Issue 2
M. Zare; M. Chorom; N. Moallemi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 1-15
Abstract
Release of urban sewage in the environment is considered a serious problem to the environment and human health while its use in agriculture is recommended as a rich fertilizer in organic matter and major nutrients affecting plant growth. In this study, the use of treated urban sewage sludge, as a cheap ...
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Release of urban sewage in the environment is considered a serious problem to the environment and human health while its use in agriculture is recommended as a rich fertilizer in organic matter and major nutrients affecting plant growth. In this study, the use of treated urban sewage sludge, as a cheap organic fertilizer, a reproducible source in the nature and a municipal waste on the chemical properties of soil and essential nutrients of olive plant and soil alone and in combination with chemical fertilizer, was investigated. This study was conducted at Shahid Chamran University of Ahvaz greenhouse with 12 treatments and 3 replications within six months. Effects of sewage sludge, chemical fertilizer and combined effects on various parameters such as ECe, pH, organic matter content and essential nutrients of olive plant and soil and olive physiological characteristics were determined. Soil nutrient concentrations and physiological function of olive plants subjected to sewage sludge increased, and soil pH significantly decreased. The effect of sewage sludge and fertilizer on the vegetative components of the olive plant, including number of lateral branches, number of new leaves, height and leaf dry weight, significantly increased. Sewage sludge improved some soil chemical properties. 150 tons of sewage sludge per hectare without fertilizer treatment had the best effect on the properties of olive plants and soil. Sewage sludge increased the number of leaf, leaf area and organic matter content about twice times comparing with blank treatment but decreased 0.4 unit pH. Effect of sewage sludge on soil potassium content was fewer than P and N.
Volume 34 - Issue 2
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 1-14
Abstract
In order to study the effects of sugar cane harvest machinery traffic on bulk density and cone index variation, a survey was conducted in 10 farms of Deabel Khozaiee sugarcane agro-industrial company, Ahvaz, in 2006. In this experiment, two types of harvesters including wheel half track and tire wheels ...
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In order to study the effects of sugar cane harvest machinery traffic on bulk density and cone index variation, a survey was conducted in 10 farms of Deabel Khozaiee sugarcane agro-industrial company, Ahvaz, in 2006. In this experiment, two types of harvesters including wheel half track and tire wheels with 14 tons of weight, versus two types of tractor and basket transporters, with 10 and 18 tons of weight, both with two axles were used. Soil bulk density was measured in 3 depths (0-5, 30-35, 60-65 cm) and cone index was determined at 80 cm depth. Results revealed increased soil bulk density at all depths. The highest amount of increase of soil bulk density with 6.69% was measured in 0-5 cm depth. Half track harvester increased bulk density more than wheel type harvester, but at 60- 65 cm depth wheeled harvester with 5.89% increase was higher than half truck harvester. Variation of soil bulk density in both transporters was not significant at any depth. Results showed that cone index measurement was only greater for half truck harvester treatment where soil moisture was near field capacity. Cone index for half truck and 18 ton transporter at 60-80 cm depth was significantly greater (p≤ 5%), but for other treatments and depth variations, it did not show any significant difference. Generally, results showed greater use of harvesters and wheel half trucks and harvest at low soil moisture could reduce sugar cane field compaction problems.
Volume 34 - Issue 1
M. Ashtari; M.A. Asoodar
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 1-12
Abstract
One of the problems of canola production is the lack of interest in farmers towards planting this crop. This could stem from lack of suitable planting method and the high amount of grain loss at harvest. In order to evaluate the effect of seeding methods, type of combine platforms and their interaction ...
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One of the problems of canola production is the lack of interest in farmers towards planting this crop. This could stem from lack of suitable planting method and the high amount of grain loss at harvest. In order to evaluate the effect of seeding methods, type of combine platforms and their interaction on canola grain yield and harvesting losses, a field experiment was conducted in Safi Abad, Khuzestan during 2007. The experiment was a split plot, arranged in a randomized complete block design with 3 replications. The seeding methods were the main plots, including two flat seeding methods with 12 and 24 cm row spacing and two row planting methods with 2 and 3 seeding lines on the row. Combine harvester platforms were the subplots, including conventional cereal platform and canola harvesting header extension. The results indicated that the seeding method significantly (P≤0.05) affected the yield, plant density at harvest time and stem diameter of canola. The highest yield (3224.92 kg/ha) was obtained with the flat seeding method with 24 cm row spacing and the lowest yield (2513.66 kg/ha) was obtained with the row planting method with 2 seeding lines on the row. Type of platform significantly (P≤0.01) affected the amount of grain loss. The grain loss of 20.99% of the total yield (593.03 kg/ha) was obtained by using the conventional cereal platform and grain loss of 13.08% of the total yield (370.48 kg/ha) was attained using the header extension.
Volume 38 - Issue 1
Soil Biology, Biochemistry and Biotechnology
Majid Baghernejad
Abstract
Abstract Introduction Drought stress is one of the important environmental factors that limit distribution and productivity of major crops. Drought stress caused by reducing the availability of external water, which makes reduces the ability of the plant’s roots to take up nutrients and induced ...
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Abstract Introduction Drought stress is one of the important environmental factors that limit distribution and productivity of major crops. Drought stress caused by reducing the availability of external water, which makes reduces the ability of the plant’s roots to take up nutrients and induced cellular and photo-oxidative damages, through the increased accumulations of reactive oxygen species. Plant growth promoting rhizobacteria and arbuscular mycorrhizal fungi by using different mechanisms such as production of siderophores, organic acids, proton, growth regulators, and other chelating agents, and creative of reductive conditions, increase dissolution of minerals and mobility of non-soluble nutrients and thus improve nutrients uptake and yield of plants. They can influence plant root morphology and change the quantity and quality of root exudates. Mycorrhizal symbiosis involves a complex interaction among plant, soil and mycorrhizal fungi. Arbuscular mycorrhizal associations' relationship are rather important in crops because they are believed to increase nutrients uptake, improve plant fitness, and plant water relations and thus increase the drought resistance of host plants. Plant growth promoting rhizobacteria improve water relations of plants in part due to increases of plant growth, nutrient uptake and antioxidant activities. Maize is an effective host of arbuscular mycorrhiza in infertile and drought conditions and its root system consists of different root types. Therefore, the objectives of this study was to evaluate the effects of Glomus intraradices, Pseudomonas fluorescens (as a PGPR bacterium) and drought stress on growth characteristics and micro-nutrients uptake of maize in a calcareous soil under maize cultivation. Materials and Methods A greenhouse experiment in a factorial completely randomized design was conducted to evaluate the effects of arbuscular mycorrhizal (AM) fungus (Glomus intraradices), Pseudomonas fluorescence, and drought stress on root colonization and absorption of micro-nutrients (Fe, Mn, Zn, Cu) by maize (Zea mays). The factors were consisted of arbuscular mycorrhizal fungus at two levels: G0 (not inoculated with fungus) and G1 ( inoculated with Glomus intraradices), bacteria at two levels: B0 (not inoculated with bacterium) and B1 (inoculated with Pseudomonas fluorescence) and drought stress at four levels: S0 (without stress), S1 (75% FC), S2 (50% FC) and S3 (25% FC). Mycorrhizal inoculum was prepared through the trap culture of forage sorghum (Sorghum biocolor L.) with spore of Glomus intraradices. The potential of inoculum (spore numbers of 12 g-1 substrates and root colonization of 80%) was measured for spore extraction and counting, and evaluation of root colonization. The bacterium used in the present experiment was Pseudomonas fluorescens and provided by soil biology and biotechnology laboratory of College University of Agriculture and Natural Resources of Tehran University, Karaj, Iran. The bacterium had a high ability to dissolve poorly soluble organic and inorganic phosphate compounds, to produce siderophores, indole acetic acid (IAA), and 1-aminocyclopropane-1-carboxylate (ACC)-deaminase enzyme. A non-sterile composite soil sample was collected from depth of 0-30 cm soil surface of Agriculture Research Station of Shiraz University, Shiraz, Iran (fine, mixed, mesic, Calcixerollic Xerochrept). The samples were air-dried and passed through a 2mm sieve. Some physical and chemical properties of studied soil are measured. The seeds were inoculated with 1mL fresh and active suspension of bacterium (population of 1×108 colony-forming units (CFU) per milliliter). After a growth period of 4 months, plant materials harvested and data were subjected to analysis of variance and means were compared by least significant difference. Results and Discussion In non microbial treatments, wet and dry weights of shoot significantly decreased whereas other measured parameters had not significant changes under drought stress of 25% FC. At each level of drought stress, root colonization significantly higher in mycorrhizal treatments than non mycorrhizal treatments. The highest root colonization percent was observed in treatments of co-inoculation of plant with both inoculants. Co-inoculation of plant with both inoculants significantly increased morphological properties and shoot nutrients uptake except Fe uptake in comparison with non microbial treatments up to drought stress of 50% FC. Conclusion All measured parameters ( leaf area, wet and dry weights of root, root colonization, shoot micronutrient uptake) except wet and dry weights of shoot significantly decreased with increasing of drought stress up to 25% of FC. Single and co-application of bacterium and fungus decreased the negative effects of drought stress under low levels of water stress. Root colonization significantly increased with single application of fungus and co-inoculation of plant with fungus and bacterium. Co-application of fungus and bactrieum increased shoot nutrients uptake except Fe uptake up to 50% FC in comparison with non inoculated treatments.
Volume 38 - Issue 2
S. Baghbani; M. Baranimotlgh; E. Dordipour
Volume 39 - Issue 1
R. Montaghami Rad; E. Ahmadi; S. Zarif Neshat
Abstract
Introduction Storage conditions of product after harvest and during storage are important factors that affect the quality parameters of the products such as color and mechanical properties. The observance of effective issues on the fruit quality, ...
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Introduction Storage conditions of product after harvest and during storage are important factors that affect the quality parameters of the products such as color and mechanical properties. The observance of effective issues on the fruit quality, such as weather conditions, harvest methods, timing of harvesting, temperature of storage and time of storage in maintaining of olive quality and reduce waste, will be very effective. Performance of mechanical testing and mechanical and colorimetric properties of products has an important role in study of qualitative and quantitative properties during storage. Moreover, the study of color and mechanical properties of products, such as olive is necessary, for use in machine design for processing and recovery processing lines in order to reduce waste. Materials and Methods In this study, two types of olives, bitter and sweetened with 1.5% NaOH were harvested and tested to study the effect of storage time on their color and mechanical properties. Olive fruits were stored in two temperatures (environmental conditions with 25 and refrigerator with 4) for 3 months. During this period, experiments were carried out at the intervals of 10 days. Universal testing machine and color meter devices were used for determining the mechanical properties and the color of olives, respectively. By performing a factorial experiment under completely randomized design, the effects of independent factors including storage time, storage temperature and type of olive on the measured properties (shear modulus, shear force, shear energy, modulus of elasticity, penetration force, yield strain, L*, a*, b*, h and c*) were studied. Results and Discussion The results of analysis of variance for shear modulus showed that the main effect of olive type, temperature, time of storage and the dual effects of these parameters were significant at the level of one percent. Analysis of variance for shear force showed that the effect of type, temperature, time of storage and interaction effects of type× temperature and type× time of storage were significant at the level of one percent. The results of data analysis for shear energy showed that the independent parameters, including the type, temperature, time of storage and the effects of dual and triple of their were significant at the level of one percent. According to the graphical results, shear modulus and shear energy of any type of olive on the thirtieth day with the fast steep increased. Water surface evaporation, changes in the texture of olive and a sharp drop in humidity are reasons for the sudden increase of shear modulus and shear energy on the thirtieth day. With increasing time of storage, shear strength and other mechanical properties for bitter and sweet olive increased. This result conformed to the results of Lavassani et al and Nanos et al. Analysis of variance of mechanical properties for olive fruit in penetration test showed that the effect of type and interaction effects of type and time of storage on modulus of elasticity were not significant. Analysis of variance of yield strain showed that the only effect of type was significant at the level of one percent. The results of mean comparison with Duncan test showed that during storage, penetration force and modulus of elasticity for bitter and sweet olive increased. This result correlated with the results of De Castro et al. The penetration force, yield strain and modulus of elasticity of sweet olives during storage were higher in comparison to bitter olives. The penetration force and modulus of elasticity of bitter and sweet samples stored at 4 were higher in comparison to the same sample in temperature of 25. This result correlated with the results of Nanos et al. Analysis of variance of colorimetric properties showed that the interaction effects of type and time of storage on L* were not significant. The effects of type and time of storage on a* and all effects on b* and c* were significant at 1% probability level. The results of mean comparison showed that the brightness and yellow of bitter and sweet samples increased with increasing time of storage compared to the first, tenth and twentieth days. The increase in L* and b* color characteristics correlated with the results of Piga et al. Color characteristics L*, b* and c* of bitter samples in each of the temperatures and days of storage were higher in comparison to sweet samples. In addition, the values of L*, b* and c* of bitter and sweet samples stored at 25 were higher in comparison to the same samples in temperature of 4. Conclusion The results of mechanical and colorimetric tests showed that by increasing the storage time, stiffness, shear strength and other mechanical parameters increased in both types of olives, and the L* and b* values of the samples were higher in comparison to the first, tenth and twentieth days. Bitter and sweet samples stored at 4 temperature displayed higher stiffness, modulus of elasticity, shear modulus, shear force and shear energy values and lower L*, b* and c* in comparison with the same samples stored at 25 temperature.
Volume 39 - Issue 2
Soil Chemistry and Pollution
M Ayeneh Heydari; M Hejazi Mehrizi; A Jafari; M Yousefifard
Volume 40 - Issue 1
A. Kiani Harchegani; S.A. Eftekhari
Volume 40 - Issue 2
Precised Equipment
N. Ahangarnezhad1; Rouzbeh Abbaszadeh; Ahmad Norouzian
Abstract
Introduction Plants are able to respond to stresses or environmental factors. Application of electricity, magnetism, monochromatic light and sonic waves for increasing growth rate is called electro-culture. These factors can affect growth of plants. Many studies have shown that magnetic fields can affect ...
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Introduction Plants are able to respond to stresses or environmental factors. Application of electricity, magnetism, monochromatic light and sonic waves for increasing growth rate is called electro-culture. These factors can affect growth of plants. Many studies have shown that magnetic fields can affect the organisms. However, the exact mechanism of this effect is still unclear. A description of possible multiple effects of magnetic field on living organisms is oxidative stress due to increased production of oxygen species that is with the mediation of iron. considering the development of the lawn field in the country and the value of this plant, the aim of this study was to investigate the influence of magnetic field on the growth of grass seeds and determine how to optimize the magnetic field. Materials and Methods In this study, the effect of AC magnetic flux density and exposure time of magnetic field on germination of grass seed (Festuca arandinacea) was investigated using an electro-culture system. Helm Holtz coils were designed to a create uniform field in the electro-culture system. Helmholtz coil radius and its average height were 18 cm, consisting of two coils to create a uniform magnetic field strength. Pulleys were made of polyethylene. After construction of pulleys, 500 turns copper wire with 1 mm diameter was wrapped around the pulleys. In the coil design, dimensions and materials were selected such that they could bear the weight of the wires and the created heat. In order to create distance between the coils, four stands were used. The stands had possibility of changing their length. Sinusoidal alternating magnetic field was created by applying 50 Hz alternating current to the coils, which were connected in series circuit. Magnetic flux densities were 0.1 and 1 mT, exposure times were 15, 60 and 240 minutes and there was a control treatment (without magnetic field). The design was completely randomized with four replications For evaluation of the electro-culture system, germination percentage, germination rate, mean germination time, and shoot length of every treatment were measured. The current of the coils was controlled using Varyak (an electrical transformer with only one coil for voltage control). Multi meter was attached in series between Varyak and Helm Holtz coil. Tesla meter was applied for measurement and detection of the magnetic field. Electromagnetic flux density 0 (for control), 1.0 and 1 mT at duration of 15, 60, and 240 minutes was applied to the grass seeds. Germinator was used with 13 hours of darkness, and 11 hours of light at constant temperature 20 ± 2° C, respectively. Daily counting of the germinated seeds was done for a week and at the specified time. More than two millimeters root seeds were counted as germinated seeds. On the last day, shoot length for at least five explants from each repeats was measured. Then all data was analyzed using SPSS software and factorial test. The analysis of variance and the mean comparison (Duncan) were performed for the data. Results and Discussion For the mean time of germination, due to the lack of significant interaction between factors, the main effect of magnetic flux density was studied. But for other indices, mean comparison was done for the interaction effects too. Generally, increase of exposure time could improve germination. The best treatment was application of 1 mT magnetic field for 60 minutes. The results showed that magnetic field had a significant influence on the measured traits and most of them showed better results comparied to the control treatment. Coparison between control and optimal treatments, showed that germination percentage, germination rate, mean time germination and shoot length improved to 124%, 155%, 8% and 64% respectively. Maximum rate, germination percentage and shoot length of grass seed obtained at 1 mT magnetic field with 60 min exposure time. Grasses have high water requirements during germination and growth and they must be irrigated constantly. If the condition of growth and germination improves, the water could be saved. Magnetic field can affect exchange of ions in the cell membrane. Distinction of this effective mechanism in electric culture requires more studies by researchers of biology and other related areas. The most investigations should be done to study the effect of magnetic fields on germination by magnets or direct current which is usually easy to create, while in this study the alternating field could have different effects. The other advantage of the system is its ability to create a uniform magnetic field and the possibility to create different fields through changing the current. Conclusions An electro-culture system was designed using alternating magnetic field to stimulate early growth of grass seed as a non-chemical, non-invasive and non-destructive driving factor in the growth. It seems electromagnetic field application can improve cultivation of grass seeds. Further is still needed in this area; the effect of fields from 2 to 4 mT at 60 to 240 minutes should be studied. However, for germination tests, a large number of treatments may lead to reducing accuracy and in this regard limitations should be taken into consideration. Further tests are needed to investigate this new approach.
Volume 41 - Issue 1
Soil Physics, Erosion and Conservation
Nasim Bazshushtarizadeh; shamsollah ayoubi
Abstract
Introduction 137Cs is an artificial radionuclide with a half-life of 30.2 years and strong gamma radiation that, due to nuclear explosions in the 1950s, and 1960s entered the earth's surface by the rain. The radionuclide has been widely used for the evaluation rates and patterns of soil erosion and deposition. ...
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Introduction 137Cs is an artificial radionuclide with a half-life of 30.2 years and strong gamma radiation that, due to nuclear explosions in the 1950s, and 1960s entered the earth's surface by the rain. The radionuclide has been widely used for the evaluation rates and patterns of soil erosion and deposition. 137Cs was rapidly adsorbed to fine particles of soil surface horizon and its distribution is basically accompanied by the physical processes of soil, such as erosion and tillage. 137Cs is distributed exponentially as a function of depth to a maximum depth ranging from 5 to 15 cm in the undisturbed soil. The basis of calculating of erosion by 137Cs method is based on comparison between the amount of 137Cs in studied soil and the reference site (local, flat, un-eroded, undisturbed and stable site) and 137Cs loss or gain, relative to the reference inventory, indicates soil erosion and deposition, respectively. So, the reliable and accurate reference estimate of 137Cs is essential. No attempt has been made to explore the variability of 137Cs inventory in the reference sites in Iran. Therefore, This study was conducted to evaluate variability of 137Cs inventory and its relationship with some soil properties at the reference site located in Fereydan district in western of Isfahan province. Materials and Methods 96 soil samples were collected from 0-15 cm and 15-30 cm depths. Moreover, for evaluation of vertical distribution of 137Cs, two profiles were excavated and 8 soil samples were collected from 0-5, 5-15, 15-25 and 25-35 cm depths. Gamma-ray spectrometry device was used for 137Cs analysis. Magnetic susceptibility values were measured using Bartington susceptimeter at low (0.46 kHz) and high (4.6 kHz) frequencies and magnetic susceptibility dependent was calculated by low and high frequency values. Soil properties including total nitrogen, organic material, cation exchange capacity, calcium carbonate equivalent, EC, pH, texture, gravel and bulk density were determined. Descriptive statistics including mean, minimum, maximum, standard deviation (SD), coefficients of variation (CV), skewness, and kurtosis were calculated by SPSS software, v.16. The distribution of variables was evaluated using the Kolmogorov-Smirnov test. Pearson correlation coefficient and regression analysis were used to examine the relationships between 137Cs and soil properties. Results and Discussion The coefficient of variation of 137Cs inventory were 15.05 and 14.05% in 0-15 cm and 15-30 cm depth respectively. The result indicated that 137Cs has uniformly distributed in studied reference site. The results of the study showed that OM, OM/Clay, CEC/Clay, EC, Sand, BD, χlf and χhf were correlated with 137Cs. The results of multiple regression analysis indicated that bulk density, clay content and magnetic susceptibility at low frequency explained 43% of total variability of 137Cs in the studied reference site. Conclusions In the present study, variability of 137cs was investigated in a reference site in Ferydan district in Isfahan Province. The study showed that 137Cs had low variability. Among the soil physical and chemical properties, Soil pH, silt, gravel, nitrogen and calcium carbonate equivalent did not show significant correlation with 137Cs. The highest positive significant correlation was obtained for BD and 137Cs. Also, magnetic susceptibility at low and high frequencies showed significant correlations with 137Cs. In the multiple regression analysis, BD, clay content, and magnetic susceptibility were included in the model for explaining the 137Cs variability. It is suggested that similar study be done in the other reference sites in the western Iran.
Volume 41 - Issue 2
Plant Nutrition, Soil Fertility and Fertilizers
Elham Mirparizi; Mojtaba Barani motlagh; Alireza Movahedi; REZA GHORBANINASRABADI; Somayeh Bakhtiary
Abstract
Introduction: Among the micronutrients required by plants, iron deficiency has the maximum limitation for agricultural crops. Iron plays an important role in synthesis of chlorophyll, energy transfer in plants, formation and synthesis of special enzymes, and fixation of nitrogen. Deficiency of iron in ...
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Introduction: Among the micronutrients required by plants, iron deficiency has the maximum limitation for agricultural crops. Iron plays an important role in synthesis of chlorophyll, energy transfer in plants, formation and synthesis of special enzymes, and fixation of nitrogen. Deficiency of iron in plants causes chlorosis or yellowing of young leaves. Iron deficiency is developed due to imbalance of metal ions including copper and manganese, large phosphorus in soil, poor aeration, low temperatures, soil iron deficiency, low organic content, and high concentration of bicarbonate in the root environment. To solve the problem of iron deficiency in plants, very expensive methods are used. Usage of solid wastes of copper melting factories such as slag as soil modifying materials can be useful in iron nutrition. The possibility of using reverb furnace slag of Sarcheshmeh Copper complex as an iron fertilizer was examined in a calcareous soil. Since copper slag contain considerable amount of iron (53.8% iron oxides), therefore, its proper management can solve the problem of iron deficiency in calcareous soils. Materials and Methods: To investigate the effect of copper slag and organic compounds on iron availability and growth of Sorghum plant, (Speed Feed cultivar), a soil sample was harvested with low soil absorbable iron and organic compound. After air-drying, the soil samples were passed through a 2-mm sieve. Some physiochemical properties of the soil sample used, organic compounds, and the slag were characterized by typical experimental methods. The experimental design was performed as a factorial experiment (copper slag and organic compounds) in a completely randomized design with three replicates. The experimental treatments included five levels of organic compound (pistachio shell and cow manure at two levels of 2% , 4% and the control sample) and 10 levels of iron (copper slag, copper slag with sulfur, copper slag with sulfur and thiobacillus, acidic slag (each at two levels), Fe-EDDHA, and control sample). The experimental treatments were incubated for 3 months. Treatments were then applied to 3 kg samples of soils and the treated samples were incubated in plastic containers at field capacity (FC) moisture content for up to 90 days. At the end of incubation period, 10 sorghum seeds were cultivated in each pot. Foliar application of Fe-EDTA with a concentration of 5 ppm in addition to the mentioned treatments. Harvesting sorghum shoot was performed 90 days after the cultivation. The plant samples were dried for 48 h at 70°C. After digestion of the plant samples by wet oxidation method, concentration of iron, zinc, nickel and cobalt were measured by atomic absorption spectrophotometer. Soil samples were also taken from the pots. After being air-dried, the soil samples were passed through a 2-mm sieve. Amount of electrical conductivity, soluble sodium, concentration of calcium and magnesium as well as iron, zinc, nickel, and cobalt were measured. All statistical analyses were performed using SAS software. Means of different treatments were compared using LSD (P ≤0.05) test.Results and Discussion: Application of acidic slag increased the soluble sodium and sodium absorption ratio and decreased the soil absorbable iron content. Application of 4 times critical level as slag (S4) increased iron and zinc absorbable by soil, as well as increased concentration of the plant iron. The copper slag with sulfur and thiobacillus developed the maximum absorbable zinc in soil. Comparison of the organic compounds indicated that cow manure has a greater influence on the amount of absorbable iron in soil, iron concentration and uptake by the plant than pistachio shell. On the other hand, with reduction of the concentration of heavy metals, its application is recommended in comparison with pistachio shell. The content of zinc, nickel, and cobalt in the studied plant did not exceed the toxicity level. Heavy metals have low mobility in the soil and are often stabilized by soil colloids or precipitate as different compounds. For this reason, their mobility and transference to shoot diminish. Conclusion: The slag from copper melting has micro nutrient including iron and zinc. Therefore, it can be concluded that the copper slag has the potential of a source supplying elements for plants. These results confirm the lack of use of acidic treatments. In addition of iron and zinc availability for plants, measurement of other heavy metals in the plant showed that the concentration of measured heavy metals was below their toxicity level. Therefore, suitability of this compound for agriculture will be confirmed. Since addition of heavy metals to soil has various environmental effects, thus repetitive use of slag and its use in large amounts are not recommended. As in absorption of nutrients, immobility in soil, stabilization of metal in the root, and preventing its transference to shoot organs are among the mechanisms of plant when exposed to high concentration of heavy metals, it is suggested that the amount of heavy metals be studied in the root.
Volume 41 - Issue 3
Kamran Azizi; Kamal Nabiollahi; Masoud Davari
Abstract
Introduction Soil salinity and alkalization are recognized worldwide as a major threat to agriculture, particularly in arid and semi-arid regions. To manage these soils a lot of data are needed and laboratory measurement is costly and time-consuming. Therefore, indirect methods that are cheap, fast and ...
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Introduction Soil salinity and alkalization are recognized worldwide as a major threat to agriculture, particularly in arid and semi-arid regions. To manage these soils a lot of data are needed and laboratory measurement is costly and time-consuming. Therefore, indirect methods that are cheap, fast and easy to access are one of the research priorities. One of these methods is visible near infrared diffuse reflectance spectroscopy. Visible and near infrared diffuse reflectance spectroscopy is a time and cost-effective approach that has been successfully used for characterizing soil properties. Materials and Methods The study area is located in Kurdistan Province, about 20 km northeast of Ghorveh city, west of Iran, and covers 260 km2. Average annual precipitation and temperature are 369.8mm and 10.8 °C, respectively. Soil moisture and temperature regimes are Xeric and Mesic, respectively. In the study area, 100 soil samples were collected (0–30 cm depth). The main land use types consist of cropland and rangeland. The soil samples were air-dried at room temperature and then, passed through a 2mm sieve. EC, pH, SAR, OC, CaCO3 and ΔMWD were measured. Sodium Adsorption Ratio (SAR) was calculated using results from the saturated paste extracts of sodium, calcium, and magnesium. The stability aggregate was measured using the difference between distributions of particle size in dry and wet sieve methods. Spectral analysis of soil samples was done using a spectrophotometric instrument with a wavelength of 350 to 2500 nm and recorded using RS3 software. After recording the spectra, different preprocessing methods were evaluated. Two models of multiple linear regression and artificial neural network were used to predict soil properties using spectral data. Results and Discussion The soil salinity of the study area ranged between low and high. The highest amount of salinity was observed in the center, south and southwest of the study area and the least amount of salinity was observed in northwest, southeast, northeast and north. The maximum amounts of acidity and sodium adsorption ratio showed that the central part of the study area has saline and sodium soils. The results showed that the best method for preprocessing of spectral data is the 1st Derivative + Savitzky-Golay filter + Mean center + SNV. The Pearson correlation coefficient between the soil properties and the spectral reflection values for each wavelength in the range of 2450-400 nm showed that there is a relatively high correlation between the measured characteristics and the spectral values of the soil. The results showed that the correlation coefficient can be positive or negative. The maximum positive correlation coefficients for electrical conductivity, soil acidity, sodium adsorption, organic carbon, calcium carbonate and aggregate stability at the wavelengths 1229, 2397, 2399, 1298, 2090, 2014, and two spectra 2257 and 660 were 0.45**, 0.43**, 0.46**, 0.61**, 0.53** and 0.40**, respectively. The maximum negative correlation coefficients for electrical conductivity, soil acidity, sodium adsorption ratio, organic carbon, calcium carbonate and aggregate stability at the wavelengths 630, 2289, 630, 1904, 1379 and 2107 were -0.47**, -0.42**, -0.44**, -0.46**, -0.55** and -0.44**, respectively. Based on the determination coefficient statistic, artificial neural network model (0.88, 0.25, 0.59, 0.68, 0.52 and 0.48 to electrical conductivity, PH, SAR, calcium carbonate and aggregate stability, respectively) had better results compared to the multiple linear regression model (0.45, 0.13, 0.23, 0.66, 0.48 and 0.28 to electrical conductivity, PH, SAR, calcium carbonate and aggregate stability, respectively). Conclusion In this study, visible near infrared diffuse reflectance spectroscopy was evaluated to estimate some properties of salt-affected soils. After recording the spectral data, the continuity curve and pre-processing of spectral data were performed. The results showed that the best method for pre-processing of spectral data is the first derivative + Savitzky filter and Glair + Mid filter + Normal standard variable. Multiple linear regression and artificial neural network models were used to estimate some properties of salt-affected soils (EC, pH, SAR, OC, CaCO3 and ΔMWD) using spectral data. Based on the statistics of mean error, root mean squared error, and correlation coefficient, the artificial neural network model had better results in estimateing the properties of salt-affected soils compared to the multiple linear regression model. Therefore, based on these findings it is suggested that soil spectral data be used as an indirect method to the estimate soil properties.
Volume 41 - Issue 4
Soil Physics, Erosion and Conservation
Hamid Kelishadi; Mohammad Reza Mosaddeghi; Shamsollah Ayoubi; Hossein Asadi
Abstract
Introduction Soil erosion is one of the major obstacles to sustainable development. A large part of Iran has an arid and semi-arid climate, without vegetation with suitable density or even completely without vegetation. Therefore, many parts of the country face high erosion and soil losses. Previous ...
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Introduction Soil erosion is one of the major obstacles to sustainable development. A large part of Iran has an arid and semi-arid climate, without vegetation with suitable density or even completely without vegetation. Therefore, many parts of the country face high erosion and soil losses. Previous studies showed an increased trend of soil erosion in Iran. Because in situ measurement of soil erosion at the farm or watershed scale is expensive and time-consuming, estimation of soil erosion from easy and ready parameters can be useful. It is well-known that aggregate stability can affect soil erosion. There are many methods developed to measure soil aggregate stability, but there is no specific method that can be used for a wide range of soil types under different land uses. This study was done to compare different methods of aggregate stability determination (i.e., splash rate measurement, shear strength measured with fall-cone penetrometer and wet sieving). Materials and Methods Twenty-eight soil samples with different textures, equivalent calcium carbonate, and organic matter were collected from surface soil layers in Isfahan and Chaharmahal-va-Bakhtiari provinces. Particles size distribution of studied the soil was measured. Very coarse sand (VCS), coarse sand (CS), medium sand (MS), fine sand (FS) and very fine sand (VFS) were measured according to ASTM sieves. Also, four components of silt (0.035-0.05, 0.02-0.035, 0.01-0.02 and 0.002-0.01 mm) were measured according to Stock's law by the pipette method. Geometric mean diameter and geometric standard deviation of particles were calculated by Shirazi and Boeresma (1984) relations. Soil splash rate (S) was measured with rainfall simulator, near-saturated soil shear strength (τ) was determined using the fall-cone penetrometer, and mean weight diameter (MWD) and geometric mean diameter (GMD) of soil aggregates were measured by the wet sieving. Results and Discussion The results of this study showed that the sand, silt and clay contents were, respectively, in the ranges of 1.5-51%, 34-73% and 11-35% in the studied soils. Most of the sand particles belonged to the FS and VFS (0.05-0.25 mm) fractions and most of the silt fraction was in the very fine silt (0.002-0.01 mm) fraction. The range of organic matter was 0.08 to 8.8% and calcium carbonate equivalent varied in the range between 10% and 63%. Generally, soil aggregate stability was low and splash erosion was high in the studied soils. The results showed that S showed significant correlations with sand, silt, and geometric mean diameter and geometric standard deviation calculated using all particle fractions, VCS, CS, MS, FS, fine silt and very fine silt. Soil shear strength (τ) had significant correlations with silt, very fine silt, geometric mean diameter and geometric standard deviation. The GMD and MWD had significant correlations with soil organic carbon. The results showed that S had significant and negative correlations with τ and GMD, and there were significant and positive correlations between τ with GMD and MWD. The S was mainly dependent on particle size distribution, while GMD and MWD mainly depended on soil organic carbon. However, both particle size distribution and soil organic carbon would affect τ. This finding might be justified by differences between mechanisms which are responsible for particles detachment. The energies induced by raindrop impact and slaking are the main forces and mechanisms responsible for detachment of particles in splash erosion and wet sieving tests, respectively while the cohesive forces between particles mainly govern soil strength in the fall-cone penetrometer test. The studied soils were clustered based on intrinsic soil properties (i.e., texture, CaCO3 and organic carbon) by using K-means method in MATLAB software, in order to evaluate the capability of different methods in different soil groups. The least significant difference (LSD) test was used in a completely randomized design for mean’ comparisons between the clusters. The mean comparison results showed that the three methods similarly predicted the variation of aggregate stability in different soil clusters. The results of clustering showed that the soil cluster with high organic matter, silt and clay contents and low sand content was more stable than other clusters. Conclusion Three methods similarly predicted the variation of aggregate stability in different soil groups; therefore, the methods might be used alternatively for aggregate stability determination. Fall-cone penetrometer can be introduced as an in situ method for evaluation of aggregate stability against splash erosion.
Volume 42 - Issue 1
Soil Physics, Erosion and Conservation
Sahar Akhavan; Soheila Ebrahimi; Maryam Navabian; Mahmoud Shabanpour; Alireza Movahedi; Ali Mojtahedi
Abstract
Introduction Soil macropores are the prominent factor in the transfer of wastewater, fertilizers, and microorganisms, including fecal bacteria to deeper soils and even underground waters. On the other hand, a vast majority of land in Iran is located in arid and semi-arid regions. Therefore, the use of ...
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Introduction Soil macropores are the prominent factor in the transfer of wastewater, fertilizers, and microorganisms, including fecal bacteria to deeper soils and even underground waters. On the other hand, a vast majority of land in Iran is located in arid and semi-arid regions. Therefore, the use of salty and unconventional waters has recently gained considerable importance. The aim of this study is to investigate the preferential transportation and storage of Escherichia coli (as an important bacterium in commonly used fertilizers) under the condition of saline water application. Materials and methods The laboratory studies were conducted in a preferential flow system with artificial macropores with different diameters (1 and 2 cm) and varying salinity treatments (1, 2 and 4 dsm-1) under a saturated flow condition. The leaching test was performed at 20°C within several phases. Microbial transfer tests were carried out in two phases with boundary conditions and flow velocities similar to the zero-phase condition. In order to evaluate the bacteria in the soil profile, after the end of the bacterial transfer test, the soil column was divided and cut into 3 layers. Two samples were collected from 3 depths and at macropore and matrix zones. The experiment was conducted in a factorial format and completely randomized design with three replications. The results showed that the mutual effect of salinity and macropore diameter was significant (at 5%) on mean output concentration (Cav), soil filtration coefficient (fλ), relative absorption index (SR), and maximal predicted depth of bacteria transfer (Zmax). Results The results indicated that the bacteria were affected by the treatments during the transfer, so that with increasing the salinity and reducing the diameter of macropores, the average bacterial concentration output decreased. The presence of macropores and the integrity of pores in a column with a diameter of 2 cm accelerated the bacterial movement and increased the pollutant outflow index due to high porosity; therefore, more bacteria passed (compared to the control column without macropores). The salinity treatment, however, served as an inhibitor and hindered further transmission of bacteria. Moreover, The macropore-free column with a salinity of 4 dsm-1 exhibited a higher refining coefficient (0.85 cfuml-1) compared to other treatments. A salinity treatment involving a 1 dsm-1 salinity and a pore diameter of 2 cm showed the least filtration coefficient (0.82 cfuml-1), so by doubling the ionic strength, 30% reduction can be seen in the bacterial filtration coefficient. Increasing the salinity up to 2 dsm-1 and decreasing the macropores diameter increased the relative absorption index. The macropore-free treatment with a 2 dsm-1 salinity showed the highest relative sorption index (0.92). Although the bacterial growth and mortality are unknown during the bacterial transfer process, according to the results, it is expected that the bacterial mortality rate increases by the salinity enhancement from 2 to 4 dsm-1 and the relative adsorption index reduction which may result in lower surface sorption. The significant treatment for the maximum predicted depth of bacterial transfer was the mutual effect of salinity and diameter at a probability level of 5%, which confirmed the significant impact of salinity on the bacterial filtration and transfer. The maximum depth of predicted bacterial transfer was obtained in the macropore-free treatment with the salinity of 1 dsm-1 (16.81 cm). The role of the underlying layers in the bacterial refinery seems to be more profound compared to the surface layer. Conclusion Overall, the results showed that the main source of transmission of bacteria is the preferential flow due to the macropore continuity. However, the salinity reduced the amount of bacterial refining by increasing the ionic strength of the soil solution. The salinity had a significant effect on the average output bacterial concentration, bacterial refining coefficient, relative sorption index, and maximum predicted bacterial transmission depth. The results of this study revealed that increased ionic strength of soil solution can enhance the bacterial refining and the further elimination of bacteria which can be effective in controlling the pollution of underground water by saline irrigation management. Regarding the quantitatively and qualitatively critical water status in the country, conditions can be provided for the use of unconventional water sources, without threatening the environment and contaminating the underground water.
Volume 42 - Issue 2
Micromorphology and Clay mineralogy
Masoumeh Pourmasoumi Parashkouh; Farhad Khormali; Shams Ollah Ayoubi; Farshad Kiani; Martin Kehl; Eva Lehndorff
Abstract
Introduction The loess-paleosol sequences in Northern Iran are important archives that represent several cycles of Quaternary climate change and can be used to complete the information gap on loess between Europe and central Asia. Last interglacial soils derived from loess in northern Iran is represented ...
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Introduction The loess-paleosol sequences in Northern Iran are important archives that represent several cycles of Quaternary climate change and can be used to complete the information gap on loess between Europe and central Asia. Last interglacial soils derived from loess in northern Iran is represented by strongly developed Bt horizons of forest soils. In Golestan and Mazandaran area, soils under the forest are mainly classified as Alfisols or Luvisols. Interestingly, E horizons are generally not found in these soils. In the Caspian Lowlands, a pronounced precipitation gradient is reflected in mean annual precipitation rates decreasing from about 1850 mm at Bandar Anzali in the west to about 435 mm at Gonbad- e Kavoos in the east. The results of the loess climosequence in Northern Iran showed that with increasing precipitation, soil pH and calcium carbonate contents decrease, whereas soil organic carbon, clay content, and cation exchange capacity increase. For years, many efforts to quantify the soil properties led to the provision of indices of soil development. Among these indices are forms and ratios of iron, morphological, and micromorphological indices. Many studies have been carried out on the loess-paleosol sequences and modern loess soils in Northern Iran with focus on micromorphology, mineralogy, and dating but more investigation is needed with an emphasis on the forest soils with well-pronounced clay illuviation as a proxy for paleo-moisture. For this purpose, we used micromorphology and soil color indices to report the effects of precipitation gradient on the variability in the formation of soils under forest vegetation. Materials and Methods The study area is located at the northern slopes of Alborz Mountain Ranges, covered with Caspian or Hyrcanian deciduous forests. Field sampling started in summer 2015. More than ten soil pedons with loess parent material were investigated based on former studies. Finally, six representative modern pedons were selected and dug in an east-west direction on loess deposits. The climate data shows that precipitation varies from 500 mm in Qapan (Pedon 1) to up to 800 mm in Neka. Physiochemical properties of soils were studied using standard methods. Thin section prepared for soil micromorphological studies were studied and interpreted based on Bullock et al. and Stoops guideline using a polarizing microscope. The micromorphological index of soil development (MISECA), suggested by Khormali et al (2003), was calculated. Also, color indices were calculated based on Hurst (1977), Torrent (1983), and Alexander (1985) by using the Munsell color chart. In all color indices, Munsell color hue converts to a single number. Results and Discussion The results showed that the downward decalcification and the subsequent clay illuviation were the main criteria influencing the assessment of soil development in this study. So, all of the soils host argillic and calcic horizons and are classified as Alfisols and Mollisols. Micromorphological studies confirmed the morphology studies in the field and the results of physico-chemical analyses. MISECA index showed pedological changes in different pedons in the studied areas. A significant positive relationship between climate gradient (increasing rainfall) and MISECA index was found. The area and thickness of clay coatings show an increasing trend with rainfall. Occurrence and preservation of clay coatings are more pronounced in more humid regions with illite and vermiculite as the dominant clay minerals. These minerals reduce the shrink/swell potential and increase the number of clay coatings present. In Argillic horizons of all pedons, except Toshan, dominant b-fabric is speckled due to carbonate leaching, while in Toshan, it is striated b-fabric. In calcite horizon, b-fabric is crystallitic. The correlation of various forms of iron with three color indices of Hurst, Torrent, and Alexander showed that Torrent and Alexander indices were better than the other one for the study area. Moreover, there was a good correlation between MISECA and Torrent color index. Conclusion The results showed that the soil evolution in the studied areas is strongly influenced by soil formation factors, especially in a climate which shows a change in the micromorphological characteristics of soils. With increasing the rainfall from the east to the west in this gradient, the amount and thickness of clay coating, as well as secondary calcium carbonate accumulation, change significantly. In addition, the micromorphological and color indices of soil evolution can be used as two indicators for assessing the effects of rainfall gradient on soil formation in northern Iran. On the other hand, knowledge of the development of modern loess-derived soils could help to better understand the paleoenvironment.
Volume 42 - Issue 4
T. Nazari; M. Baranimotlgh; E. Dordipour; R. Ghorbani nasrabadi; S. Sefidgar Shahkolaee
Abstract
Introduction One of the most important needs in crop planning is the evaluation of different systems of plant nutrition. plant nutrition in a correct way can preserve the environment and increase efficiency of agricultural inputs. Humic acid contains many nutrients that increase the soil fertility and ...
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Introduction One of the most important needs in crop planning is the evaluation of different systems of plant nutrition. plant nutrition in a correct way can preserve the environment and increase efficiency of agricultural inputs. Humic acid contains many nutrients that increase the soil fertility and soil organic matter content and thus affect plant growth and yield. In the present study, the effect of soil and foliar application as well as fertigation application of humic acid on iron and phosphorous availability of canola (Hyola 308) was evaluated. Materials and Methods The soil was air-dried and ground to pass through a 2-mm sieve and then was analyzed to determine soil physical and chemical properties using standard methods. A greenhouse experiment was carried out with 10 treatments in four replications. Treatments include humic acid soil application at three levels (1, 2 and 4 g.kg-1 soil), foliar application at three levels (0.1, 0.2 and 0.4%) and three fertigation levels (1000, 2000 and 4000 mg L-1) and control). Soil application in the form of humic acid powder and in cropping time based on the soil weight of the pots and for spraying and use along with irrigation water, each of the spraying and together with irrigation water levels is divided into three equal parts and in three stages (plant establishment, stem elongation and flowering). At the end of growth period (for 139 days), vegetative growth indices were determined and then plants were harvested and stem and leaves were separated. Phosphorous content in plant extracts was measured by molybdate vanadate method (yellow method) and iron concentration in the samples was determined by atomic absorption (AAS-Unicam-919). Statistical analysis was conducted via SAS software and mean comparisons carried out by LSD test at 5% probability level. Results and Discussion Results show that the application methods and the different levels of humic acid had significant impacts (p < 0.01) on the all parameters but they had no significant effects on the numbers of leaves. The maximum leaf fresh weight was 4.34 gr per plant which obtained water irrigated treatments with 2000 mg/lit. However, there was no significant difference between water irrigation with 4000 and 2000 mg/lit humic acid concentrations. Besides, maximum leaf dry weight was 0.37 gr in the plant that was water irrigated with 4000 mg/lit, however there was no significant difference between water irrigation with 4000 and 2000 mg/lit humic acid concentrations. Also, the maximum stem dry and fresh weight was 5.92 and 1.53 gr which observed in water irrigated with 2000 mg/lit. The application methods and the different levels of humic acid had significant impact (p<0.01) on the content and absorption of Fe and P excluding the Fe content in the root. The maximum Fe content in stem and seed were 321.25 and 85 mg/kg was observed in the treatment of humic acid with water irrigation of 2000 mg/lit. Also, in the treatment of spraying with 0.4 % of humic acid, the maximum of Fe concentration (245.46 mg/kg) was obtained. The humic acid molecules can pass from the cell membranes and cause iron reduction in the Apoplast and increase the availability of Fe. Because of the reduction effect of humic acid on the availability and accumulation of Fe in the plant tissue, increasing in the Fe absorption with humic acid treatment is observed. The increase in the accumulation of Fe by humic material might be due to the releasing phenolic material in the root rhizosphere. The maximum P concentration in the leaf, stem and seed were 0.40, 0.72 and 0.897 respectively that was observed in the treatment of water irrigation with 2000 mg/lit with humic acid. Due to the availability of phosphorus and other nutrients for wheat, humic acid increases the plant yield in the reproductive stage of seeding. Conclusion Results of the study show that humic acid can ameliorate the negative effect of a large amount of phosphorus on iron availability. In fact, humic acid, due to providing nutritional balance for the plant, prevents negative effects caused by the high amounts of specific elements such as phosphorus. Also, the results showed that all three humic acid application methods increased vegetative growth parameters, and iron and phosphate availability for canola plant compared to control. But in general, 2000 mg/L acid humic with irrigation water was more effective than two methods of soil and foliar application.
Volume 42 - Issue 3
M. Soleimanzadeh; F. Khormali; M. Sohrabi; R. Ghorbani Nasrabadi; M. Kehl
Abstract
Introduction Biological soil crusts are a widespread community of cyanobacteria, green alga, lichens, mosses, and other organisms. These crusts play important roles in arid and semi-arid ecosystems, such as carbon and nitrogen fixation, soil protection against water and wind erosion, and water retention. ...
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Introduction Biological soil crusts are a widespread community of cyanobacteria, green alga, lichens, mosses, and other organisms. These crusts play important roles in arid and semi-arid ecosystems, such as carbon and nitrogen fixation, soil protection against water and wind erosion, and water retention. In arid and semi-arid regions, the biological soil crusts also possess a key role in the global carbon cycle due to the carbon fixation (photosynthesis) and its release (respiration) into the atmosphere. These organisms increase the organic carbon content of the soil in arid and semi-arid regions by performing photosynthesis. Soil organic carbon is a mixture of various components and one of the important characteristics for soil quality evaluation. Biological attributes of soil quality include many soil components and processes related to the organic material cycle, such as total organic carbon and nitrogen, microbial biomass, carbon and nitrogen mineralization, labile fractions of elements, the activity of enzymes, and animals and plants in soil. These biological attributes respond rapidly to natural and human-derived changes, and therefore they are used as indices for quality of soils. Biological soil crusts are the main cover of the loess soil surface in the northern parts of Golestan Province. The region that was selected to be studied in the province was Maraveh Tappeh. This region has arid and semi-arid climate and is attributed to low vegetation, especially on the slopes to the south. In these slopes, biological and physical crusts are dominant. Therefore, a study was conducted to investigate the effect of lichen biological soil crusts on organic carbon and different fractions of labile carbon. Materials and Methods After extensive field studies, two species of lichen biological soil crusts were collected and transferred to the laboratory for identification. The results elucidated that the studied species were Diploschistes Diacapsis (Ach.) Lumbsch, and Fulgensia Fulgens (Sw.) Elenk, based on taxonomical identification. Soil sampling was done from 0-2 and 2-5cm depths under lichen biological and physical crusts. Soil samples were transferred to the laboratory, and then the organic carbon, carbohydrate, permanganate oxidizable carbon, microbial biomass carbon, cold-water extractable organic carbon, and hot-water extractable organic carbon were measured by standard methods. Results and Discussion Results show that lichen biological soil crusts led to the increase in soil organic carbon and different fractions of labile organic carbon related to the physical crust. As a result, the highest values for these traits were observed in soils affected by lichen biological soil crusts. Soil covered by the Diploschistes Diacapsis species had the highest amount of soil organic carbon and different fractions of labile organic carbon in comparison to the Fulgensia Fulgens species in 0-2cm depth, which had a significant difference at 5% probability level. the physical crusts had the least amount of soil organic carbon and different fractions of labile organic carbon related to the lichen biological soil crusts, which was caused by the loss of topsoil and the lack of biological coverage. There was a positive correlation between the measured traits. There was a high correlation between hot water-extractable carbon and carbohydrate. There were high correlation coefficients between organic carbon with microbial biomass carbon, hot water-extractable carbon, and carbohydrate. In general, there was a high correlation coefficient between hot water-extractable carbon with organic carbon and other labile fractions of organic carbon except for cold water-extractable carbon, whereas there was low correlation coefficient between hot water-extractable carbon with organic carbon and other labile fractions of organic carbon. Conclusion According to the results attained from the following study, the presence of biological soil crusts on loessial soils led to the increase in organic carbon, carbohydrate, permanganate oxidizable carbon, microbial biomass carbon, cold-water extractable organic carbon, and hot-water extractable organic carbon. Diploschistes Diacapsis Species have the highest impact on organic carbon and different fractions of labile organic carbon. The High correlations show that the best attributes to evaluate the quality of soil organic carbon in the studied area are microbial biomass carbon, carbohydrate, and hot water-extractable carbon and these may be used as a good indicator to evaluate soil quality. The studied area falls within the arid and semi-arid climate, and given the erosion-prone nature of loess deposits, improper management may lead to severe problems, such as erosion and dust production. Hence, protecting lichen biological loess crusts against human activity and livestock grazing may result in lower water and wind erosion, and increase soil quality in this region.
Volume 33 - Issue 1
Volume 33 - Issue 2
Volume 32 - Issue 1
M. Razzaghi; N Khademol Hosseini; M almasi; L Joukar; S.H. Ahmadi; A. Astakhr
Volume 43 - Issue 1
Hosna Kiafar; Mousa Mousavi; Ali Ebadi; Noorollah Moallemi; Mohamad Reza Fattahi Moghadam
Abstract
Background and ObjectivesPeach is one the most important horticultural crops in Iran. Peach has always been considered for its high nutritional value and its taste in the world. Therefore, improving its quantity and quantity is very important. Today, substances that improve the quality and quantity of ...
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Background and ObjectivesPeach is one the most important horticultural crops in Iran. Peach has always been considered for its high nutritional value and its taste in the world. Therefore, improving its quantity and quantity is very important. Today, substances that improve the quality and quantity of the product are very much considered, they are including materials such as hormones, nutrition elements(Ca). Nanoparticles are materials that their size are smaller than 100 nanometers. on the other hand the importance and role of calcium in improving the fruit quantity and quality are interesting for scientists. In this study, the effect of calcium nanoparticles on qualitative and quantitative characteristics of peach fruit was studied.Materials and methodsThis experiment was carried out during the years 2015 - 2017 as a factorial based on a randomized complete block design with three replications in a commercial garden located in Hashtgerd, Karaj. In this experiment, three concentrations 0, 10 and 20 mg/l of calcium chloride nanoparticles, at the time of flower popcorn, flower budding and twenty days after flower opening were sprayed. Then, when the fruits were harvested, the soluble solids, acidity, fruit set, vitamin C content, tissue firmness, calcium content of fruit tissue, fruit length, fruit width and fruit weight were measured.Results The results showed that calcium nanoparticles in both cultivars improved qualitative and quantitative traits. Result showed There was not significant difference between treatments and cultivars in flowering time and Calcium nanoparticles cannot have any effect on flowering time and flowering time is affected by the genetics and the environment. Treatments with calcium nanoparticles increased the fruit set rate in this study. The results showed that there was a significant difference between cultivars in length and width of fruit at 1% level, and Early Alberta fruits were larger than Valad Abadi cultivar. There was a significant difference between weight of two cultivars at 1% level and between treatments at 5% level. Early Alberta had a higher fruit weight than Valad Abadi cultivar and no difference observed between the control and treated trees. Increasing in concentration of treatment did not effective on fruit weight. On the other hand the highest amount of TSS, fruit set, vitamin C, calcium content of fruit flesh were observed in 20 mg/l concentration of calcium nanoparticle treatment. in the amount of vitamin C was significantly different between two cultivars at 1% level and between treatments at 5% level. Vitamin C in both cultivars increased with increasing treatment concentration. Among the two cultivars tested, the amount of vitamin C in early Alberta cultivar was higher than the Wald Abadi cultivar, and the highest levels of vitamin C were found in Early Alberta, at a concentration of 20 mg/l. Calcium content in fruit tissue of early Alberta cultivar was more prevalent than Wald abadi cultivar and the most effective treatments were treatment of calcium nanoparticles with concentration of 20 mg/l Calcium nanoparticles in the Valad Abadi cultivar increased the firmness of the fruit tissue, while there was no significant difference among treatments in Early Alberta cultivar. This difference can be attributed to the difference between genetically basis of the two cultivars. Calcium nanoparticles treatments did not affected the fruit length of Valad Abadi cultivar. There was no significant difference between treatments and control, while in Early Alberta, with increasing concentration of calcium nanoparticle, fruit length increased. Calcium nanoparticles treatment increased the weight in both cultivars while there was no significant difference between the concentration of 10 and 20 mg/l of calcium nanoparticles.DiscussionCalcium caused a change in the enzymatic activity of certain enzymes involved in metabolism and effective enzymes in nitrate absorption and can improve fruit quality and quantity. Calcium was considered as a binding agent between cell walls which result in higher fruit firmness and calcium nanoparticles can improve shelf life in peach fruit. calcium increases the strength of the middle blade and the cell wall by creating calcite packets, and decreases the activity of the polygalacturonase enzyme's. Calcium also reduces respiration, reduces the production of ethylene, and reduces the activity of the polyagalacturonase enzyme from appetite and softness of the fruit. Calcium increases the activity of antioxidant enzymes such as superdioxidase, catalase and peroxidase and calcium treatment can improve fruit quality and quantity. Our result showed calcium nanoparticles are effective in improving peach fruit quality and quantity.
Volume 44 - Issue 1
Precised Equipment
Hojat Hejazipoor; Jafar Massah; Keyvan Asefpour Vakilian; Mohsen Soryani; Gholamreza Chegini
Abstract
One of the most important issues in spraying fields and greenhouses is reducing the use of pesticides, reducing the dangerous effects of spraying, protecting the environment, improving the quality of spraying and increasing people's health. Children have weaker immune systems and are unable to detoxify ...
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One of the most important issues in spraying fields and greenhouses is reducing the use of pesticides, reducing the dangerous effects of spraying, protecting the environment, improving the quality of spraying and increasing people's health. Children have weaker immune systems and are unable to detoxify toxic and harmful compounds. For this reason, the adverse effects of poisons on children's health are more important than adults, and the need to reduce the use of poisons and follow the principles of spraying to prevent children from developing cancer is twofold. In this study, the robot sprays by measuring the volume of plant mass and in order to reduce the consumption of poisons. The robot is mechanically designed to be able to move between rows of products and open its manipulator step by step and take deep pictures of each plant in front of it, then analyze the image of each section and observe the plant volume. Detect and spray the same section based on the calculated volume. The process of imaging, volume detection and spraying of the solution based on the estimated volume is repeated at each stage of manipulator opening until the height of the plant is completed and at the end the whole manipulator is retracted.Robot acts intelligently in detecting plant height and closes in the last section after imaging and spraying the solution. The manipulator is able to assess and spray plants up to 270 cm in height. The above robot consists of different parts including camera chamber and nozzle, nozzle and Kinect American camera version 1, manipulator and manipulator actuator mechanism, pump and solution tank, processor, Arduino and relay boards, cart and robot actuator system. To design the above robot, first the static forces applied to the manipulators were examined and then the kinematic calculations of the manipulator were performed. The result of the calculations showed the accuracy of the kinematic equations. After performing calculations to design the robot, examining the environmental conditions and considering the construction cost, the three-dimensional model of the robot was designed in Solidworks 2016 software and based on the above model, the construction work was done step by step. The robot is controlled by Matlab 2010 software. The entire robot working algorithm is coded in Matlab software. For this reason, the main part of controlling the robot is the laptop processor. The laptop controlled by the robot is located in the built-in place behind the robot and transmits all the robot commands to the set of operators through the Arduino board and the relay board. The input information is transmitted to the processor by the Kinect camera, and the processor makes the necessary decisions according to the coded program. Finally, the output commands from the processor are transferred to Arduino board and the relay board to start the actuators. ADM A10-4655M APU processor was used. Developer Toolkit Browser v1.8.0, KinectExplorer-D2D, and Kinect for Windows Software Development Kit (SDK) were used to connect the Kinect camera to a Windows laptop. Two coefficients α and β are needed to determine the plant volume in each section. α is the average plant volume of several plants that has been calculated manually and β is the correction factor multiplied by the amount of plant volume estimated by the robot so that the actual volume of sprayed solution is more in line with the plant needs and the opinion of relevant experts. The volume estimated by the robot in each section is the product of the volume factor multiplied by the average plant volume of the plant (α). The volume factor is the average observed plant width (M) divided by the distance between two consecutive plants in pixels (D). Multiply the volume of the plant observed in the section by multiplying the volume factor by the calculated volume (α) using the Scale Invariant method (independent of the distance from the camera to the object).To calculate the average plant volume manually, several plants should be selected randomly and the plant volume should be calculated by computational methods or flooding method. Then introduced the average volume of these few plants as α to the program. Therefore, the more accurately the manual volume is calculated, and the greater the number of selected plants, Finally, the value of α and the final volume of the plant will be calculated more accurately. The robot should be able to spray the right amount of solution depending on the type of plant and its conditions. Spraying the solution to the plant may not be scientifically justified by experts and specialists according to the type of plant, time of spraying, poison concentration and plant needs. Therefore, the correction factor β should be multiplied by the volume estimated by the robot to the actual volume. Spray the solution to the plant according to the needs of the plant and the opinion of experts. The results of the evaluation show that the robot is able to spray different amounts of solution in the detection of plants with different volumes and the amount of solution sprayed by the robot was proportional to the volume of plants. The average volume of solution sprayed by the robot is 27.1 cc and the average volume of solution sprayed by the worker is 33.1 cc. Also, the standard deviation of the average volume of solution sprayed by the robot and the worker is 2.94 and 3.11, respectively. In other words, the robot is able to spray more accurately and the amount of poison consumption in the robot is estimated less than the worker. It was mentioned that the evaluation of the robot is reported in order to reduce the consumption of acceptable poisons. The feature of being online includes collecting plant information and spraying the solution moments after data processing is one of the important features of the above research. Also, the ability of the robot in online and scale invariant (independent of the distance from the camera to the object) evaluation of the robot was considered acceptable and useful.
Volume 46 - Issue 1
Soil Biology, Biochemistry and Biotechnology
Mahboobeh Abolhasani Zeraatkar; Ahmad Tajabadi Pour
Abstract
Introduction: Plants are usually exposed to a wide variety of abiotic stresses which can seriously inhibit plant growth and development. To address this, numerous strategies have been proposed and used by researchers, including increased irrigation rounds, cultivation of salinity- and drought-resistant ...
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Introduction: Plants are usually exposed to a wide variety of abiotic stresses which can seriously inhibit plant growth and development. To address this, numerous strategies have been proposed and used by researchers, including increased irrigation rounds, cultivation of salinity- and drought-resistant genetically modified crops (GMO crops), and application of plant-growth-promoting rhizobacteria (PGPRs). PGPRs can act as an efficacious, long-lasting, and crucial option to ameliorate the negative impacts of abiotic stresses in crops. Plant growth promoting rhizobacteria can serve as key in sustainable agriculture by improving soil fertility, plant tolerance, crop productivity, and maintaining a balanced nutrient cycling. Consequently, search for new strains of PGPR for biofertilizer and development of microbial diversity map for any region is helpful. Hence, the present study investigates the effect of native salinity-resistant PGPRs on the physiological and biochemical characteristics and productivity of alfalfa plants in soil under salinity stress.Materials and methods: The present study was based on a completely randomized factorial design. The experiments were conducted on alfalfa plants (Bami variety) in four repetitions and under two levels of salinity (control and 200 mM sodium chloride and calcium chloride) with five strains of PGPRs from Sinorhizobium meliloti sp., two positive controls (i.e., 20 mg/kg of phosphorus and 70 mg/kg of nitrogen fertilizers), two negative controls (i.e., no fertilizer and no bacteria), and two treatments (including positive control and negative control). Growth parameters (dry weight of aerial parts, roots, and nodules), osmolytes (reducing sugars, soluble proteins, and proline), uptake of K+ and K+/Na+ ratio, and concentration of malondialdehyde (MDA) in alfalfa plants in non-saline and saline soils were measured at the end of 60-day experiments.Results and discussion: The analysis of variance (ANOVA) results revealed a significant effect of salinity on the dry weight of aerial parts and roots, the weight and number of nodes in each pot, the K+/Na+ ratio in roots and aerial parts, and the concentration of reducing sugars, proline, MDA, and soluble proteins in the aerial parts. The effect of PGPRs was also found to be significant on all the above traits. Under no salinity stress and compared to negative control plants, the dry weight of aerial parts in plants inoculated with superior PGPRs (SM89, SM16, and SM65) was raised by 2.3, 1.9, and 1.8 folds, while this increase in plants inoculated with mild (SM73) and weak (SM21) PGPRs was 1.4 and 1.2 folds, respectively. Under salinity stress (200 mM NaCl and CaCl2) and compared to negative control plants, the increase in dry weight of aerial parts of plants inoculated with superior PGPRs (SM89, SM16, and SM65) was increased by 4.2, 4, and 2.1 folds, while this increase in plants inoculated with mild (SM73) and weak (SM21) PGPRs was raised by 1.7 and 1.2 folds, respectively. Despite a drop in the growth of aerial parts in plants under salinity, salinity-resistant PGPRs were able to significantly enhance the growth of aerial parts of plants in saline conditions compared to the controls (receiving no fertilizer and PGPRs). Salinity stress reduced other growth parameters, the rate of K+ uptake, and the K+/Na+ ratio, while it contrarily increased the concentration of reducing sugars, soluble proteins, proline, Na+, and MDA in plants. Inoculation of alfalfa plants with two superior PGPRs (SM89 and SM16) was found to significantly improve growth parameters, uptake of K+, osmolytes, and K+/Na+ ratio in alfalfa plants under non-saline conditions and salt stress, compared to control plants (not inoculated with PGPRs and receiving no fertilizer). Ultimately, each inoculation of plants with all three superior PGPRs reduced the concentration of MDA and Na+ in alfalfa plants.Conclusion: Experiments on the biochemical and physiological plant–PGPR interactions revealed that plant responses to stresses are largely controlled by microbial communication. PGPRs can trigger systemic resistance in plants through their metabolites, which function as extracellular signals, thereby enabling plants to survive under abiotic stresses. In the present study, microbial inoculation was found to significantly improve the physiological functioning of the plants. The results revealed that adding native salinity-resistant PGPRs to the soil can diminish the negative effects of salinity stress on alfalfa plants. Likewise, inoculation and enrichment of the plant's rhizosphere with beneficial and resistant microbiomes were efficient for sustaining the growth of plants under abiotic stresses such as salinity.
Volume 47 - Issue 1
Land Evaluation and Suitability
Nikrooz Bagheri; Alireza Sabzevari; Ali Rajabipour
Abstract
Introduction: One of the decision-making methods using quantitative data is multi-criteria decision-making, which helps the manager make rational decisions by considering different conflicting criteria. Planning for the optimal use of water and soil resources, in addition to their conservation, involves ...
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Introduction: One of the decision-making methods using quantitative data is multi-criteria decision-making, which helps the manager make rational decisions by considering different conflicting criteria. Planning for the optimal use of water and soil resources, in addition to their conservation, involves increasing production, income growth for farmers, and rural economic prosperity. Given the limited resources, the optimal cropping pattern should be appropriate and effective for each region. The selection of an appropriate cropping pattern and, if necessary, adjusting the cultivation based on regional and national needs and the relative advantage of products in different regions is of great importance. So far, many studies have been conducted to optimize cropping patterns. The main reasons for the low productivity in agricultural production are the inappropriate allocation of resources and production factors. Although farmers are faced with various options for agricultural activities and crop selection, their production factors are limited. By formulating and implementing an optimal cropping pattern in a region, it is possible to familiarize farmers with the available potentials while considering the constraints of production resources, reducing risk, ensuring system stability, improving income in production, and creating the groundwork for the growth and prosperity of agricultural regions. This leads to agricultural development, increased profitability, and profitability. Decision-making is one of the most important and fundamental tasks of management, and the quality of decision-making determines the achievement of organizational goals. However, the main focus of research has been on improving the productivity of crops based on water and soil resources, with little attention given to the subject of agricultural mechanization and the criteria of regional operators. Considering the criteria of farmers in decision-making processes increases the acceptance of programs and better collaboration in implementing them. Additionally, most studies have only used one decision-making method, but each decision-support method provides a unique outcome and may differ from the results of other methods. Therefore, in this study, multiple decision-making methods were evaluated and compared to determine the best method to be used. Based on the given explanation, the objective of this research is to prioritize the factors influencing the determination of suitable cropping patterns for agricultural products using four different decision-making methods and introduce the best method. Materials and Methods:The research area is sited in Silakhour Plain, in Lorestan Province, between the cities of Doroud and Borujerd, at geographical coordinates 38 degrees 36 minutes north and 48 degrees 31 minutes east, in coordinate zone 39. In this study, Analytic Hierarchy Process (AHP), TOPSIS, VIKOR, and Simple Weighted Average methods were used for decision-making. The parameters investigated in this study included technical-agricultural, economic, macro-governmental, soil and climate, social, and production support factors. These factors included sub-factors such as the presence of mechanized planting and harvesting equipment, farming unit larger than one hectare, water requirements of plants, distance from the place of consumption, farming unit smaller than one hectare, crop profitability, required capital, suitable market for the product, customs and farmer habits, farmer education, crop cultivation experience, guaranteed purchase of the product, government incentive policies, physical characteristics of the soil in the region, chemical characteristics of the soil in the region, average temperature during the growing season, elevation of the region, average rainfall in the region, insurability of the product, sustainability of crop production, availability of seeds compatible with regional conditions, and prevalent pests in the region. To validate all judgments made in the analytic hierarchy process method, the inconsistency ratio was calculated using Expert Choice11 software. Based on this, the inconsistency ratio was calculated to be less than 0.1 in all steps of this method. If the consistency ratio is 0.1 or less, it indicates consistency in the comparisons and confirms the validity of the judgments. To reach a general consensus on the ranking of parameters, the method of merging average ranks was used. Results and Discussion: In this study, 22 indicators were identified, including the presence of mechanized planting and harvesting equipment (0.061), operational unit larger than one hectare (0.021), crop water requirement (0.014), distance from consumption site (0.008), operational unit smaller than one hectare (0.006), product profitability (0.125), required cash capital (0.116), suitable market for the product (0.020), agricultural customs and habits (0.028), education of the farmer (0.006), crop cultivation experience (0.130), guaranteed purchase of the product (0.3), government incentive policy (0.122), physical characteristics of the soil in the region (0.075), chemical characteristics of the soil in the region (0.022), average temperature during the growth season (0.022), elevation of the region (0.008), average precipitation in the region (0.006), insurability of the product (0.013), stability of crop production (0.007), availability of seeds compatible with the regional conditions (.0004), and common pests in the region (0.0002). Among the mentioned parameters, cash capital (0.236), water requirement for cultivation (0.233), product profitability (0.098), and operational unit larger than one hectare (0.039) are considered the most important factors. Certain purchase of the product (0.3), product profitability (0.0125), government incentive policy for products (0.122), and required cash capital for cultivation (0.116) were identified as the most important factors influencing the cropping pattern, respectively, using the hierarchical weighted method. product profitability and required cash capital are among the influential factors in the design of cropping patterns for agricultural products. The results showed that the ranking of agricultural products for inclusion in the regional cropping pattern differs in each decision-making method. Although grains and sugar beets have high rankings in all groups, it is necessary to validate and finalize these methods with integrated approaches to reach a general conclusion. In a multi-criteria decision-making problem, multiple decision-making methods may be used because decision-makers do not limit themselves to one decision-making method, and they may obtain different results using different methods. In fact, in such situations where the results of different methods of multi-criteria decision-making are not the same, the question is which option should be chosen. To reach a general conclusion, it is necessary to validate and finalize these methods with integrated validation and finalization approaches. Among the integration methods,
Volume 45 - Issue 2
gholamreza Adim; Elham Malekzadeh; Esmael Dordipour; Farshad Kiani; Hassan Mokhtarpour; seraj Moazzemi
Abstract
Introduction In recent years, ensuring the continuous and sustainable production of healthy food products along with environmental protection and paying attention to agricultural economic and environmental problems is very important. Although the use of chemical fertilizers has a high yield of plants, ...
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Introduction In recent years, ensuring the continuous and sustainable production of healthy food products along with environmental protection and paying attention to agricultural economic and environmental problems is very important. Although the use of chemical fertilizers has a high yield of plants, its destructive effects in the long-term are known on the soil biological, physical and chemical properties and environmental pollution. Therefore, a strategy must be considered that can improve soil health and quality as well as produce a high plant yield. Organic manures increase the growth, yield and quality of plants by improving soil conditions and the balance of essential elements. An integrated plant nutrition management system by reducing the use of chemical fertilizers is known as one of the ways to achieve the expected yield and meanwhile, minimize the adverse environmental effects of chemical fertilizers in the world.Materials and Methods The objective of this study was to evaluate the effect of single and combined use of chemical fertilizer (urea, triple superphosphate, potassium sulfate as NPK) with organic and biological fertilizers on the yield and yield components of transplanted canola (Brassica napus L.). Experiment was conducted in a randomized complete block design with six treatments and three replications (18 experimental units) in the 2019-2020 crop year at the Iraqi Agricultural Research Station in Gorgan, Iran. Treatments included: 1) Control (without fertilizer, T1), 2) Chemical fertilizer (T2), 3) Poultry manure (T3), 4) Compost (T4), 5) 50% Chemical fertilizer+ 50% Poultry manure+ 50% Compost (T5), 6) 50% Chemical fertilizer+ 50% Poultry manure+ 50% Compost+ Biofarm-1 biofertilizer (T6). Chemical fertilizer was applied based on soil test including nitrogen equivalent to 250 kg/ha urea was added in three stages during planting, stem elongation, before flowering; phosphorus equivalent to 150 kg/ha of triple super phosphate; potassium equivalent to 50 kg/ha of potassium sulfate, respectively. Organic fertilizers were calculated based on their total nitrogen contents and the equivalent of pure nitrogen recommended based on the soil test for chemical fertilizer and by assuming 50% mineralization rate of organic fertilizers in the soil. Biofertilizer was applied as seed inoculation plus spraying on the plant base in two stages of 4 to 8 leaves and stem elongation. Chlorophyll index was measured in the middle of the flowering stage by using SPAD. After physiological maturity, yield and yield components including pods per plant, numbers of seeds per pod, pod length, 1000-seed weight, seed yield, protein and oil contents of grain were recorded. Results and Discussion The results showed that the effect of fertilizer treatments was significant on yield and yield components (p <0.01). The highest 1000-seed weight, grain yield, protein content of the seed, number of seeds per pod, pod length and pods per plant were recorded in the treatment of 50% chemical fertilizer+ 50% Poultry manure+ 50% Compost+ Biofertilizer (T6) which increased by 21.9%, 43.7%, 33.8%, 29.2%, 37.2% and 37.6%, respectively, in compared to the control treatment (with the lowest values). The pods per plant, 1000-seed weight and grain yield were not significantly different between the combined treatments of chemical fertilizer+bio-organic fertilizers (T6) and integrated use of chemical and organic (T5) fertilizers (p <0.05). The control treatment (T1) by 2248.37 Kg/ha of grain yield (the minimum amount) decreased by 43.7% and 38.3% compared to T6 and T5 treatments, respectively. The chemical treatment (T2) and integrated application of chemical fertilizer+ bio-organic fertilizers (T6) showed the most positive effect on the chlorophyll index compared to other fertilizer and control treatments (with the lowest index, 43.66). Chlorophyll index in the T2 and T6 treatments increased by 35.6% and 33.7% compared to the control treatment (T1), respectively. The treated plants by alone use of organic fertilizers (T3 and T4) without notable difference produced the highest grain oil (by an average of 45.73%) which increased by 6.6% compared to the chemical fertilizer (T2) and control (T1) treatments by an average of 42.7%.Conclusion Combined use of chemical fertilizer with bio-organic fertilizers had the most positive effect on yield and yield components, and often showed significant difference with the single application of chemical and organic fertilizer treatments (T2, T3 and T4). Therefore, the combination use of chemical and bio-organic fertilizers is a better option to increase the yield and yield components of transplanted canola than the single use of chemical fertilizers. The highest pods per plant, pod length, number of seeds per pod, chlorophyll index, protein content, chlorophyll, 1000-seed weight, and grain yield were related to the integrated application of chemical fertilizer with bio-organic fertilizers (T6 and T5), so it can be inferred that the use of a mixture of organic, biological and chemical fertilizers is an effective approach to reduce the using of chemical fertilizers and their destructive environmental effects, as well as increase the yield of transplanted rapeseed
Volume 46 - Issue 2
Soil Biology, Biochemistry and Biotechnology
Elham Sadeghi; REZA GHORBANINASRABADI; Seyed Ali Reza Movahedi Naini; Mojtaba Barani Motlagh; Mostafa Khoshhal Sarmast; Mohammad Reza Pahlevan Rad
Abstract
Introduction Plant growth and crop productivity may be adversely affected under unfavorable environmental conditions, such as a lack of organic matter in the soil. To counteract the negative impacts of these challenges, a unique strategy is required. The paucity of organic inputs, which is common in ...
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Introduction Plant growth and crop productivity may be adversely affected under unfavorable environmental conditions, such as a lack of organic matter in the soil. To counteract the negative impacts of these challenges, a unique strategy is required. The paucity of organic inputs, which is common in conventional agricultural production, can lead to soil degradation, erosion, and loss of soil organic matter, which are unfortunate consequences. Soil organic amendments have been shown to have beneficial effects on crop production and a wide range of soil properties in agricultural systems. However, the limited availability of phosphorus (P) in soil can significantly restrict crop growth and productivity, particularly in maize crops. Adequate P supply has been found to enhance early maturity, crop quality, and yield. However, the prolonged use of chemical fertilizers such as NPK has been found to have adverse effects on soil fertility and crop quality. As a result, the combined application of organic and chemical fertilizers has been proposed as an effective approach compared to the single application of organic or chemical fertilizer alone. Therefore, this study aimed to assess the potential benefits of using compost and Triple Super Phosphate fertilizer (TSP) application on the chemical and biological properties of soil, as well as the properties of forage maize (cv. SC704), in loess soil.Materials and Methods A factorial experiment was conducted using a completely randomized design with three replications. A total of 36 samples were performed in two separate cultivated and incubated experiments. A pot experiment was conducted to invwstigate the effects of simple and enriched compost, containing urea and Streptomyces, and varying amounts of TSP fertilizer (0, 10, 40, and 100 mg/kg), on soil properties and maize plant growth. In addition, an incubation experiment was conducted to measure the effects of the same treatments on soil microbial biomass and activity. The effect of treatments were analyzed as factorial under a completely randomized design. The biomass of maize plants was measured at the time of harvesting (the time from planting to harvesting of forage maize was 80 days). Some parameters such as available phosphorus, substrate-induced respiration, microbial biomass carbon, and some enzyme activity (acid phosphatase, alkaline phosphatase, catalase and urease) were measured in soil.Results and Discussion The findings of this study indicated that the application of compost and TSP fertilizer had significant effects on plant biomass. Specifically, compost application led to an increase in microbial biomass carbon and enzymes activity (acid phosphatase, alkaline phosphatase, catalase and urease) in the soil, ultimately promoting plant growth. Moreover, the combined application of compost and TSP fertilizer increased the availability of phosphorus, substrate-induced respiration, and microbial biomass carbon in the soil. Based on the findings, the combined application of TSP and compost resulted in further increases in substrate-induced respiration (63-168%), microbial biomass carbon (72-167%), available phosphorus (29-103%), and enzyme activity (acid phosphatase (4-21), alkaline phosphatase (14-34%), catalase (13-32%), and urease(54-159%)) compared to the application of each amendment alone. This suggests that the addition of both TSP and compost promotes the availability of easily accessible nutrients for microbial growth and soil enzymes (acid phosphatase, alkaline phosphatase, catalase and urease) activity. The highest amount of available phosphorus, microbial biomass carbon, substrate-induced respiration, catalase activity and urease activity in cultivated soil (23%, 270%, 93%, 68%, 1.8%, respectively) and incubated soil (18%, 243%, 90%, 53%, 1.2%, respectively) were observed in C2P3 treatment. The results also indicated that the enriched compost+TSP treatment led to the highest substrate-induced respiration and microbial biomass carbon, followed by simple compost+TSP, enriched compost only, simple compost only, TSP fertilizer only, and the control. The increase in enzyme activity (P<0.01, r=0.90), and available phosphorus (P<0.01, r=0.60) in the soil positively influenced plant growth. Specifically, the simultaneous application of compost and TSP had a greater effect on maize plant biomass. The highest root biomass (2.80 g), stem biomass (10.4 g), and leaf biomass (2.27 g) were observed in the enriched compost and 100 mg kg-1 TSP treatment, which differed significantly from the other treatments.Conclusion The results of this study demonstrated that the addition of compost and TSP to loess soils can promote microbial biomass carbon, substrate-induced respiration, enzyme activity (acid phosphatase, alkaline phosphatase, catalase, and urease), available phosphorus, and maize plant growth. Moreover, the use of compost can protect soil microbial and enzymatic activities in loess soils. Thus, the simultaneous application of enriched compost with TSP can reduce the use of chemical fertilizers and their negative environmental impacts.
Volume 43 - Issue 2
Mostafa Jafarizadegan; Reza Amiri Chayjan; Roya Karamian
Abstract
Introduction Edible Button Mushroom (Agaricusbisporus) is one of the crops that is widely used today as a food source. Mushrooms after harvesting due to high humidity, high respiration rate, lack of cuticle and severe enzymatic activity, with persistence and quickly than other vegetables rot and discoloration ...
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Introduction Edible Button Mushroom (Agaricusbisporus) is one of the crops that is widely used today as a food source. Mushrooms after harvesting due to high humidity, high respiration rate, lack of cuticle and severe enzymatic activity, with persistence and quickly than other vegetables rot and discoloration begins immediately after harvest. To increase shelf life, edible mushroom must undergo processing processes. Drying is one of the most common methods of processing and preserving edible mushrooms. Vacuum-infrared drying is conducted by lowering moisture at low pressure to improve the quality of the high nutritional value product. Since button mushrooms have many applications due to their high nutritional value and medicinal uses, the best drying mode should be chosen to have the least negative effect on the quality properties and ingredients of the powder. Materials and Methods Fresh edible button mushroom After washing were cut by a cutter at 5 mm thickness and dried using a vacuum-infrared dryer at three temperature levels of 40, 55 and 70 ° C and three vacuum pressure levels of 20, 40 and 60 kPa. Then the dried mushroom slices were milled and powdered using a mill machine for one minute. To homogenize the particle size, the button mushroom powder was sifted by a laboratory sieve with mesh No. 50 (cavity size 0.5 mm).In this study, the effect of vacuum-infrared drying variables including indoor air temperature and vacuum pressure on the thermal properties (effective moisture diffusion coefficient and drying energy consumption) of button mushroom and chemical (total phenol content) and qualitative (color indices as ΔL *, Δa * and Δb*) button mushroom powders were studied. Statistical analysis of data and optimization of drying process were performed using response surface methodology and central composite design (CCD). After determining the optimum point of vacuum-infrared dryer, loose and compacted bulk density, work index, Hassner ratio, angle of repose, and button mushroom powder slides were measured at optimum point and Finally the flow-ability of the edible button mushroom powder was determined. Results and Discussion The results showed that as the chamber temperature increased, the rate of evaporation of tissue moisture increased, which resulted in a decrease in the drying time of the edible button mushroom thin layers with vacuum-infrared dryer. Effective moisture diffusion coefficient of drying of edible button mushroom thin films ranging from 1.8 ×10-9 m2/s (40 kPa pressure and temperature 40 °C) to 8.9×10-9 m2/s (20 kPa pressure and 70 °C temperature) was varied. The results showed that the air temperature of the drying chamber had a positive effect on the effective moisture diffusion coefficient. This is because increasing energy and heat consumption increased the activity of water molecules and, as a result, more moisture penetrated outside the product at higher temperatures. The maximum amount of specific energy consumption was 1269.73 MJ/kg (60 kPa pressure and 40 ° C) and the lowest amount was 408.36 MJ/kg (40 kPa pressure and 70 °C). The results showed that at constant pressure with increasing temperature, as the drying time decreased sharply, the amount of specific energy consumption also decreased. The phenolic content of button mushroom powder was in the range of 270 mg/g (20 kPa pressure and 40 ° C) and 1.3 mg/g (40 kPa pressure and 70 ° C). As the temperature increased, the total phenol content decreased. The results showed that increasing the temperature caused a greater difference between the color indices of L*, a * and b* of button mushroom powder than fresh mushroom. Increase in temperature caused more darkening (decrease in L* index), decrease in redness (decrease in index a*) and decrease in yellowness (decrease in index b*) of mushroom powder. In general, color indices were closer to the values of fresh fungal samples at low temperatures. The optimum drying point of button mushroom was obtained at 40° C and vacuum pressure of 40.823 kPa. The optimum value of the independent variables including effective moisture diffusion coefficient, specific drying energy consumption, total phenol content and final color indices of edible button mushroom ΔL*, Δa* and Δb* were 3.06×10-9 m2/s, 1088 MJ/kg, 2.76 mg/g, 15.28, 2.55 and 9.26, respectively. The results showed that drying under lower temperature and medium vacuum pressure increased the desirability index. The flow-ability of edible button mushroom powder was reported to be good. Conclusion According to the results of drying tests of edible mushrooms, the following results of this study are obtained in infrared vacuum drying: 1- The effect of air temperature on all variables of button mushroom response was significant in vacuum-infrared dryer. 2- The air inlet temperature to the dryer had a negative effect on the specific energy consumption of the drying process and the total phenol content of the button mushroom powder. 3- Increase in air temperature caused a greater difference between the color indices of L*, a* and b* button mushroom powder than fresh mushrooms. 4. The results showed that drying under mild conditions (lower temperature and medium vacuum pressure) increased the desirability index. 5-Flow-ability of edible button mushroom powder was reported to be good.
Volume 44 - Issue 2
Masoomeh Ahmadzadeh; Ebrahim Sedaghati; Roohallah Sabri-Riseh; Asghar Rahimi; Narges Hatami; Ali Akbar Mohammadi Mirik
Abstract
Introduction; Rising global demand for food, along with the limitation of arable land, has posed a major challenge for agricultural researchers. Given that the development of agricultural lands is not practically possible, most attention should be focused on increasing the production yield per unit area. ...
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Introduction; Rising global demand for food, along with the limitation of arable land, has posed a major challenge for agricultural researchers. Given that the development of agricultural lands is not practically possible, most attention should be focused on increasing the production yield per unit area. One of the basic approaches to increase crop yield is the consumption of more types of inputs, especially chemical fertilizers, despite their application poses problems for humans, soil and the environment. In addition to decreasing the use of chemical fertilizers, organic fertilizers can be considered as a suitable solution to solve this problem. Organic compounds and biomass are the main factors of soil fertility, maintain soil fertility as well as its productivity. One way to increase soil organic substance is the applying organic fertilizers such as living compounds (bacteria, yeast, Azolla) and non-living compounds (compost tea, amino acids, humic acid and fulvic acid). Arbuscular Mycorrhizal Fungi are cosidered as beneficial microorganisms. Arbuscular mycorrhizal fungi promote plant growth by establishing a symbiotic relationship with plants. The colonization of plant roots by these fungi increases plant resistance to biotic and abiotic stresses, enhances growth through increasing elements uptake, improves the water flow of plants, and protects plants against diseases. Due to the importance of some food products such as Zea mays, investigation of various aspects of the mycorrhizal fungi application and their effect on these products is important.Materials and Methods; In this study, in order to investigate the efficacy of some organic compounds and microorganisms on the colonization of arbuscular mycorrhizal fungi and uptake of some elements trough the plant roots, a factorial experiment in greenhouse conditions was conducted in a completely randomized design with three replications for 3 months. This study involved the fungal factor at three levels, Funneliformis mosseae (FM), Rhizophagus intraradices (RI), and Rhizophagus irregalaris (RIr), and the organic enhancer factor at seven levels (Azolla, P. fluorescens VUPf5 bacterial strain, Amino acid complex, Humic acid, Yeast, Bacterial siderophore and Compost tea).Results and Discussion; The results of this study showed that the highest root mycorrhizal colonization percentage by Funneliformis mosseae (FM) was observed in bacterial (93%), humic acid (90%) and Azola (76%) treatments, respectively. Treatments of Azola and humic acid with 96% and compost tea with 82% showed the highest effect on R. intraradices (Ir) colonization. Also, Azola (96%) and compost tea (90%) had the greatest effect on the root colonization percentage by R. irregalaris (Rir). According to the results, the main increase in root colonization percentage by three mycorrhizal species was observed in Azola, humic acid, compost tea and bacterial treatments. The results showed that some compounds increased the concentration of nutrients in the roots and shoots of the treated plant. The function of these compounds is as a stimulant in mycorrhizal fungi and it seems mainly via root stimulation and rooting and creating signals related to the roots of the plant and mycorrhizal fungi. According to the results, all mycorrhizal species significantly increased the amount of phosphorus (69.5%) in the shoot under the compost tea application. Treatment of amino acid along with R. irregaluris caused to increase in the concentration of iron, compared to the control. Application of R. intraradices along with amino acid increased manganese concentration by 2.87 times compared to the control. Simultaneous application of siderophore and RI, FM and Rir increased the concentration of zinc 2.16, 2.55 and 1.81 times compared to the control, respectively. Results of the present study indicated an increase in the uptake of elements by all three species of mycorrhizal fungi and the performance of these fungi accompanied with compost tea, amino acid complex and siderophore had a better outcomes compared to the control. The highest uptake of phosphorus, zinc and manganese was observed using R. intraradices and iron in inoculated plant with R. irregaluris. The mean comparison of different treatments effect revealed no significant differences between non- mycorrhiza and mycorrhiza-treated samples, while in comparison with the control, their differences were significant. Overall, concomitant use of mycorrhizal fungi with azolla, bacterial and humic acid has the greatest increase in the mycorrhizal root colonization and treatments of compost tea, amino acid complex and siderophore has the highest impact on nutrient content increase in plant.Keywords: Arbuscular mycorrhizal fungi, Elements content, Root colonization, Synergistic effect
Volume 44 - Issue 3
Houra Fayyaz; Nafiseh Yaghmaeian; Atefeh Sabouri; Ahmad Shirinfekr
Abstract
The rapid growth of population demands higher land use efficiency to ensure food security. The most appropriate way to reach this goal is to increase yield per unit area. In this regard, the assessment of soil fertility and productivity is a prerequisite for developing sustainable agriculture. Soil fertility ...
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The rapid growth of population demands higher land use efficiency to ensure food security. The most appropriate way to reach this goal is to increase yield per unit area. In this regard, the assessment of soil fertility and productivity is a prerequisite for developing sustainable agriculture. Soil fertility indicates the soil capability to provide optimum conditions for plant growth. Assessing soil fertility is an essential need to identify environmental-friendly strategies leading to more sustainability in agricultural systems. Soil fertility directly and indirectly affects the yield and crop quality. In order for food security and increased food production to be achieved, the development of a useful method for assessing soil fertility and productivity is fundamental. Various modeling techniques have been proposed as a useful tool to determine soil fertility. An assessment of the soil fertility status by using a soil index could provide key information to improve strategies and effective techniques for the future to achieve sustainable agriculture. The present study was conducted: (1) to determine the soil fertility index (SFI) using two methods which are conceptually different from each other including: Fuzzy-AHP and parametric methods; (2) to identify the main soil limiting factors for tea production; and (3) to compare two methods of quantitative assessment of soil fertility in relation to tea yield in tea cultivation with different productivities in west Guilan province.Materials and Methods Based on the mean annual tea yield, the selected tea cultivation were divided into low, medium, and high productivity. Sixty-six soil samples were collected from 0 to 30 cm depth. The green tea leaves were harvested at a 2 m2 plot at each site. In this research, clay, silt, and sand content, mean weight diameter of soil aggregates, bulk density, soil pH, electrical conductivity, soil organic carbon, total nitrogen, available phosphorus, available potassium, available copper, and zinc were measured by conventional methods. Then, the soil fertility indices of tea cultivation with different productivities were determined by fuzzy-analytical hierarchy process (SFI-Fuzzy AHP) and Parametric (SFI-Parametric) analyses. The Fuzzy analytical hierarchy process is a combination of factor weights of AHP with the fuzzy values of each parameter. The product of values generated from individual fuzzification of parameters with their corresponding factor weights. All soil parameters were tested using one-way analysis of variance and the differences among means were analyzed using Tukey's significant difference test at the probability level of 0.05.The coefficients of determination for the linear regression between the two SFI values and tea yields were conducted.Results and Discussion Results indicated that the effect of pH, available potassium and copper, mean weight diameter, and bulk density on tea yield was significant (p <0.01). The highest of organic carbon, mean weight diameter, available potassium and copper were obtained in high productivity. The highest of soil pH and bulk density were related to low productivity. The main soil limiting factors for tea production were soil organic carbon, available potassium, and soil pH. The results showed that for both SFI-Fuzzy AHP and SFI-Parametric methods, the highest and lowest soil fertility indices were related to high and low productivity, respectively. The mean SFI- Fuzzy AHP of the high productivity tea were significantly higher than low productivity tea cultivation. It was found that SFI- Fuzzy AHP is superior to SFI-Parametric to evaluation of soil fertility for tea production .So that, the correlations between crop yields and SFI- Fuzzy AHP (R2= 0.63) is higher than SFI-Parametric (R2= 0.50).Conclusion Understanding the soil fertility status is one of the important aspects of sustainable soil management in order to optimal crop production and prevent environmental degradation. Considering the importance of yield as an important indicator in the sustainable management of agricultural ecosystems, it is expected that there is great potential for increasing crop yield by improving soil fertility. The SFI- Fuzzy AHP of the high productivity tea were significantly higher than low productivity tea cultivation and created more differentiation between various soil fertility classes in tea cultivation. Therefore, determining the soil fertility index by Fuzzy-AHP method to evaluate the soil fertility of tea cultivation is superior to the parametric method. Based on the obtained results, it is suggested that for the optimal tea production, in addition to the application of potassium fertilizer, the exact amount of which should be estimated based on the soil test results, the organic matter application should also be considered.
Volume 43 - Issue 3
Maryam Izadi Bidani; A Jafari; Mohammad Hadi Farpoor; Mojtaba Zeraatpisheh
Abstract
Introduction: Soil digital mapping represents a set of mathematical computations to predict the distribution of soil classes in the landscape. . The digital identification of soils as a tool for creating soil spatial data provides ways to address the growing need for high-resolution soil maps. The use ...
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Introduction: Soil digital mapping represents a set of mathematical computations to predict the distribution of soil classes in the landscape. . The digital identification of soils as a tool for creating soil spatial data provides ways to address the growing need for high-resolution soil maps. The use of digital soil mapping technique has been expanded considerably; therefore, new methods of mapping and preparing digital maps have been developed by researchers to eliminate the limitations of traditional methods. This approach relies on statistical relationships between measured soil observations and environmental covariates at the sampling locations. Digital soil data is increasing based on new processing tools and various digital data. The present study was conducted with the purpose of digital soil mapping in Kouhbanan region of Kerman based on a Multinomial logistic regression model. Materials and methods: The study area is located in southeastern Iran, northwest of Kerman city, in Kouhbanan distinct. This study covers a 2000 ha area. In this study, a Latin hypercube sampling design was applied and the sampling was done according to the difference in landforms (geomorphology map), topography (including digital elevation map) and geology. Finally, the geographic locations of 70 profiles were identified. Soil profiles were described according to U.S. Soil Taxonomy (Soil Survey Staff, 2014) and finally, the soil samples were taken from their diagnostic horizons. The collected soil samples were transferred to the laboratory, and some physical and chemical analyzes were performed based on routine standard methods. Environmental data include the parameters derived from the digital elevation model, Landsat satellite images (remote sensing indexes), geology map, geomorphic units (geomorphology map) and legacy soil map of the study area. All environmental variables were derived using ENVI and SAGA software. In this research, a multinomial logistic regression model was used to predict soil classes and the modeling was done in R software using nnet package. It is worth noting that leave-one-out cross validation was used for validation. Estimation of predictive accuracy of soil classes was also done using the overall accuracy index and Kappa coefficient.Results and discussion: The results showed that the soils of the study area were mainly classified in the Aridisols and Entisols orders. The modeling results showed that the terrain attributes were recognized as the effective auxiliary variables in the prediction process of soil classes. This confirms topographic importance on soil genesis in the studied area. After that, geomorphology map was an important tool in soil mapping that helps to increase predictive accuracy. Among the soil classes, the prediction of Haplocambids was accompanied with low accuracy, while Haplosalids great groups were predicted with high accuracy. The low estimation accuracy of the great group of Haplocambids is probably due to the low sample size of this class of soil in the study area. A good identification of the relationships between the predictor variables and the target variable depends primarily on the size and distribution of the sample in the layers. There were only two examples of Haplocambids in the area. Therefore, low accuracy is expected because the model has failed to establish a relationship between this class with environmental variables and makes it difficult to identify threshold values for classifying soil classes and, consequently, a poorly trained model. It is also possible that low prediction accuracy is the result of the conceptual model being incomplete, since there is no characteristic feature that can help model training and ultimately prediction. Among the soil great groups, the best predictions were obtained for the great group of Haplosalids, which demonstrates high values of user accuracy and reliability. Accurate prediction of the class of Haplosalids is highly correlated with the spatial distribution of indices such as wetness index and NDVI. Kappa index and purity map were calculated 0.45 and 0.65 for digital soil map derived from multinomial logistic regression. In the predicted map, six major groups of Haplosalids, Haplocambids, Haplocalcids, Haplogypsids, Calcigypsids and Torrifluvents were identified. The great groups of Haplocalcids, Haplosalids, and Calcigypsids cover most of the area and the great groups Haplocambids and Haplogypsids occupy lowest of the area. The great group of Haplosalids is located in the north of the region and in the piedmont plain landform. Haplocalcids great groups were most commonly found in alluvial fan landform, while Calcigypsids are located in pediments, alluvial fans, and piedmont plain landforms. Haplocambids and Haplogypsids great groups are located more in the geomorphic surface of the alluvial fan and the piedmont plain, respectively. The parts of the region with the most variations or diversity of soil classes are exactly where the geomorphological map has the most segmentation. Therefore, the presence of different soil classes in the least-differentiated and most similar regions is resulted to an inefficient conceptual model and poor prediction results. Conclusions: The results showed that topographic parameters were the most important and powerful variable in modeling, and confirms that topography or relief is the most important soil forming factor in the study area. Predictive results of soil classes in Kuhbanan area of Kerman province showed that geomorphological map in the study area is very useful and necessary and also is effective in understanding and communicating between soil and landscape. Using this map as a qualitative auxiliary variable can explain much of the variability of soils in the study area. Careful field observation, satellite imagery consideration, study and interpretation of data obtained from soil profiles indicate that the study area has been evolved by geological, geomorphological, and hydrological processes that lead to the formation of various landforms including rock outcrops, hills, pediment , alluvial fan and plain. For the multinomial logistic regression model in the study area, terrain attributes have the most influence on the prediction of soil classes and soil properties than the remote sensing indices. The strong relationship between soil data and environmental parameters is one of the factors influencing model accuracy. Logistic regression models will have great potential in predicting soil classes if a complete understanding of the study area and proper selection of auxiliary variables are carried out.
Volume 45 - Issue 4
maryam sebti; F. Khormali; afshin soltani; kamran Eftekhari; abdolazim ghanghermeh; esmaeil dordipour
Abstract
Introduction Increasing concerns about global warming and climate change have led to special attention to soil and its capability in carbon sequestration in recent years. About 540,000 hectares of soils in Golestan province are under agronomic activities and so far no studies have been conducted on soil ...
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Introduction Increasing concerns about global warming and climate change have led to special attention to soil and its capability in carbon sequestration in recent years. About 540,000 hectares of soils in Golestan province are under agronomic activities and so far no studies have been conducted on soil organic carbon changes and its interactions with climate change. The total organic carbon in soils is approximately twice the amount of carbon atmosphere, so changes in soil carbon have significant effects on climate change. On the other hand, factors such as climate change or changes in land use and management affect soil organic carbon changes. As soil temperature increases, the rate of organic carbon decomposition will increase, which potentially increases the average release of soil carbon dioxide emission into the atmosphere. Therefore, finding low-cost and rapid methods for estimating soil organic carbon in large ranges and predicting its changes in the future has became a necessity.Modeling is a tool that can be used to evaluate the feasibility of various land management techniques, and with the help of the results, the best methods can be selected and researched. In the field of soil organic carbon studies, the RothC model is one of the most widely used models, which is of great interest to researchers due to its simplicity and availability of inputs. Climatic changes are also investigated using the output of general circulation models (GCMs) under greenhouse gas emissions scenarios. These data are used after exponential microscale, in which Lars-WG statistical method has been used in this research.Materials and methods The purpose of this study is to investigate the status of soil organic carbon storage in agricultural lands of Golestan province and the effect of climate change on soil organic carbon storage in the coming decades. Therefore, in order to conduct this research along the northeast_southwest of the province were selected 3 points in 3 arid climates, semi-arid and Moist climate. In selected points, soil samples were collected by digging 3 profiles and several augers and soil organic carbon, soil texture and soil apparent specific weight were measured (year 2018). The Roth C model has been used to investigate changes in soil organic carbon storage in the future. Roth C model has been used to investigate future changes in soil organic carbon storage. In order to validate the Roth C model, the results of previous studies (1997 and 2004) were used. Also, the climatic data used in this project were extracted from the statistics of 1371 to 1398 weather stations of Chat, Kalaleh and Ramyan and using the output of general circulation models (GCMs), scaled by Lars WG6 model and precipitation and temperature data were predicted of future decades.Results and Discussion The study of temperature changes showed that by 2040, based on scenario 4.5, the temperature will increase between 0.6 and 0.8 and based on scenario 8.5 between 0.6 and 1.3 °C. Also, by 2080, based on scenario 4.5, the temperature increase was predicted between 1.5 and 2.3 and based on scenario 8.5 between 2.2 and 3.2 °C. Climate change in different regions can reduce, increase or no change in precipitation. According to the forecast of the third report of the InterGovernmental Panel on Climate Change, precipitation will increase in winter and decrease in the summer. Based on the findings of this study, the amount of precipitation in the studied stations will increase in the future (in 2040 and 2080) based on two scenarios of 4.5 and 8.5. The results of prediction of soil organic carbon storage show that in 2040 based on scenario 4.5 the amount of soil organic carbon storage in agricultural land use will decrease between 0.5 and 5.3 tons per hectare. Also, based on scenario 8.5, the reduction of soil organic carbon storage in these lands was predicted between 0.8 and 6 tons per hectare. Based on these results, the greatest reduction in soil organic carbon storage was predicted in the humid and rainy areas of the province in 2040. According to this research, in the three investigated stations, in 2080, based on scenario 4.5, the amount of soil organic carbon storage in agricultural land use will decrease between 1.5 and 13.1 tons per hectare. However, in this year, based on MIROC5 and MPI-ESM-MR climate models in Sufian station, we will see an increasement in soil organic carbon storage between 0.6 and 3.9 tons per hectare. Also, according the scenario 8.5, in 2080, the reduction of soil organic carbon in these lands is predicted between 0.5 and 10.5. According to these results, the greatest reduction in soil organic carbon storage in 2080 was calculated in wet and rainy areas (Ramian station).Conclusion According to the obtained results, the Rothamsted model has been able to simulate the dynamics of soil organic carbon storage in the study area with appropriate accuracy. The output of the four climate models showed that future temperature changes will increase in 2040 and 2080 based on scenarios 4.5 and 8.5. these findings are consistent with the results of most climate studies that have predicted temperature enhancement in the future decades. According to the findings of the current research, the amount of precipitation in the studied stations will increase in the future (in 2040 and 2080) based on two scenarios of 4.5 and 8.5. The results of Roth C model simulations for predicting soil organic carbon storage showed that soil organic carbon storage will decrease in 2040 and 2080 in both climatic scenarios. According to these results, with increasing of temperature, the rate of decomposition of soil organic carbon increases. Increasing the rate of decomposition in agricultural land use due to the lack of surface vegetation in periods of the year causes the waste of soil organic carbon in the form of CO2 in the upper layers of the soil. Some studies have shown that low vegetation cover (agricultural compared to rangeland) areas will be severely affected by climate change and will lead to soil organic carbon waste in these areas.
Volume 44 - Issue 4
Marzie Tabibi; Seyed Mohammad Safieddin Ardebili; Mohammad Javad Sheikhdavoodi
Abstract
Introduction Cooling systems such as refrigeration and air conditioning are considered as basics of everyday life. However, the required energy for the above-mentioned applications is mainly generated by non-renewable electricity. Due to the depletion of fossil fuels as a source of electricity, the development ...
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Introduction Cooling systems such as refrigeration and air conditioning are considered as basics of everyday life. However, the required energy for the above-mentioned applications is mainly generated by non-renewable electricity. Due to the depletion of fossil fuels as a source of electricity, the development of renewable energies for such systems is necessary. Considering all these issues, as cooling needs, most of the time coincides with the solar radiation availability; therefore, exploring solar energy seems an exciting idea. A number of investigations were performed to design/develop new cooling techniques using solar energy. A solar cooling system is capable of considerably reducing the environmental effects of traditional refrigerating machines while allowing significant energy saving. The present work searches for the best choice of configuration/design factors of food refrigeration systems combined with solar-powered absorption chillers unit in Ahvaz as a case study. Materials and Methods In the present study, a linear parabolic collector with specific dimensions, was made, so that first, the initial design of the collector with longitudinal dimensions of 1 and a width of 0.6 meters was selected by Katia software, and then using related relations and calculations of other structural parameters based on which the collector was built, the collector simulation was performed using NASA radiation data for the place and time of the experiments and by using the Transient Simulation Software and its performance in the days of the month July, August and September 2019 were reviewed and evaluated. Also, the necessary calculations were performed on the results of performance tests by Excel software, and diagrams of changes in the radiant energy absorbed by the collector and the efficiency of the radiated energy absorbed were drawn from 10:00 AM to 6:00 PM. Using the diagrams obtained from the system simulation in TRNSYS software, it is concluded that the built-in collector has the ability to produce a fluid with a temperature above 98 degrees Celsius required for the absorption chiller in July, August, and September. Results and Discussion According to the evaluations of the collector's performance in the three months of July, August, and September from 10 AM to 6 PM showed that collector energy and efficiency reached their maximum values in July with 318.240 w-h/m2 and 63.05 %, respectively. While in August, the amount of energy and efficiency was found to be 299.311 w-h/m2 and 61.94%, respectively. The minimum value of the parameters were recorded as 283.379 w-h/m2 and 61% in September, respectively. The potential analysis conducted showed an excellent saving potential in terms of energy obtained. According to the results, the useful collector energy was achieved to be 227.664 w-h/m2, 217.006 w-h/m2, and 210.406 w-h/m2 in July, August, and September, respectively. According to the obtained results, the maximum refrigeration load needed for the studied cold storage was about 126324 w. According to the results, the average energy obtained for the collector in the three months of July, August, and September was about 216.054 w-h/m2. Finally, the area of the collector was calculated, the results showed that the required surface of the collector was found to be 584.687 m2.Conclusion Solar cooling system for food products cold storage in Ahvaz city is a promising and innovative alternative to decline the peak energy consumption generated by the combustion of fossil fuels, especially during the summer months.
Volume 43 - Issue 4
Zahra Amiri; Seyed Mehdi Nassiri; Mohammad Hossein Raoufat; Mohammad Amin Nematollahi
Abstract
Introduction: Oilseeds after cereals ranked at second place as human’s food sources. Among them, sunflower is one of the main oilseed for cultivation. Because of increasing demand rate for edible oil import, it is necessary to avoid any grain loss during harvesting and processing of oilseeds. In ...
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Introduction: Oilseeds after cereals ranked at second place as human’s food sources. Among them, sunflower is one of the main oilseed for cultivation. Because of increasing demand rate for edible oil import, it is necessary to avoid any grain loss during harvesting and processing of oilseeds. In some sunflower fields, mechanical harvesting is hardly done by combines due to difficulty for movement as well as the small-cultivated area. Then, manual harvesting and processing of sunflower heads and grains are appropriate and most used field operations. Detachments of grains from heads is a tedious work and labor-intensive operation. Also, form medical and ergonomic point of views it makes physical problem for workers. All commercial equipment thrash field dried sunflower heads, entirely. Therefore, some wastes are produced at preharvest (in field), threshing and separation processes. Some research have been conducted to adjust combine to decrease grain losses. Cylinder rotational speed and type, distance between cylinder and concave, heads moisture content and threshing unit feed rate were such adjustment. However, none of the detached grains from head without head threshing. On the other hand, losses to about 46% during harvesting the sunflowers with the combine, a partially mechanized approach for grain detachment was chosen in this study. Materials and methods: To do this an existing sunflower seed detacher unit (Jahani, 2014) was equipped with cleaning unit. In addition, the unit efficiency was improved by optimizing the device settings. This device consisted of a feeding conveyor belt, two series detacher cylinder with 8 cm rubber fingers covered all through their peripherals in segregated patterns, cleaning unit, two electric motor and deriving mechanism (belt and pulley). Cleaning unit comprised an axial flow fan and an inclined guide canal for grain movement. Fan was selected in such a way that separate the gross waste materials mixed with grain, detached from heads by laboratory test using a terminal velocity test rig. Slope and material of canal was determined by laboratory trials using a test rig to measure sliding coefficient of grain batches. For evaluating the unit performance, laboratory experiment was carried out at four levels of rotational speed of the detacher cylinders (300, 450, 510 and 600 rpm) and four levels of grain moisture content (7, 15, 20 and 27% db) in three replications. Cylinder rotational speed and feeding belt speed were selected based on Janani’s research results. Feeding belt speeds were adjusted in such a way that the speed ration of linear velocity of cylinders to feeding belt were constant and about 72.2 as reported by Jahani (2014). Moisture content levels were considered based on harvesting, processing and storage conditions of sunflower grains. Raw data were used to compute percentage of seed detachment, percentage of separation and grain fracture percentage. Results: ANOVA revealed that main factors of cylinders rotational speed and moisture contents and their interaction significantly affected percentage of separation (p < 0.01). Increasing in moisture content reduced the amount of detached grains from head due to flexibility of grains at higher moisture content and damping impact of rubber fingers. In addition, it was reported that lower moisture content produced lower adhesive force between grain outer surface and the pod. On the hand, increasing in rotational speed increased the amount of detached seed because of impact of rubber fingers and stored kinetic energy in shelled grains. The most detaching was obtained at 600 rpm and 5% moisture content. The rotational speed and grain moisture content and their interaction significantly (p < 0.01) affected percentage of fractured grains. Moisture content had more share for grain failure than rotational speed. Higher fracture was observed at lower moisture contents and higher cylinder speeds, so that it was around 6.4% at 600 rpm and 7% moisture. According to the results, cleaning was affected by moisture content alone and higher percentage took place at lower moisture contents because of lighter produced wastes. Overall, considering all above aforementioned indices, cylinder rotational speed of 600 rpm and grain moisture content of 20 % was the appropriate adjustment set for grain detaching. In such adjustment, detachment rate was as high as 94.6 %, grain fracture was limited to 0.27 %, cleaning was 68 % and the output capacity of the machine of 268 kgh-1 was achieved. More adjustment on fan speed is required to increase the rate of cleaning to approach hundred percent of cleanness.
Volume 31- Issue 1
S. Rajaee; F. Raiesi; H.A. Alikhani
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 35 - Issue 1
M. Mohammadi; M.A. Asoodar; A. R. Abdali Mashhadi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 25 - Issue 1
N. Lovemi; M. Almassi; M.J. Sheikhdavoodi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 32 - Issue 1
A. Mostaan
Volume 35 - Issue 2
Shaheen Noorbakhsh; Ali Doaguei; Ahmad Ghazanfari Moghaddam
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 13-23
Abstract
Rose water residues are by-products of rose water industries. These residues do not have any industrial usage and they are returned to soil as crop fertilizer. In this research, the effects of adding rose water distillation residues to soil in different particle sizes and weight proportion were investigated ...
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Rose water residues are by-products of rose water industries. These residues do not have any industrial usage and they are returned to soil as crop fertilizer. In this research, the effects of adding rose water distillation residues to soil in different particle sizes and weight proportion were investigated and changes in mechanical strength, and water holding capacity of soil and the growth of barley were determined. The experiments were performed using a 3 × 3 factorial design in which the weight proportions of the residues were in three levels of 4%, 8% and 12%. The second factor was the size of the residues in three sieves meshes of 6, 16 and 20. The results indicated that with increase in the weight level of residue more moisture was retained by the soil, and the size of the soil particles had lower effect on water holding capacity of the soils. The mechanical strength of the soil decreased with increase in both weight proportion and the particle size of the residues. The length of the stems and roots did not show any definite trend with the variations in factors. In this research, the change in moisture content of the soil was expressed as a linear function of time and residues weight proportionas well as the particle size. The resulting model was well fitted to the experimental data (R2>0.98).
Volume 36 - Issue 1
Saeid Hojati; Ahmad Landi; Heyam Alekasiri
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 13-22
Abstract
Wastewaters from different industries contain great amounts of heavy metals which can contaminate the ground water after entering the soil. Few studies have been conducted on the application of clay minerals such as sepiolite in preventing the leaching of these elements. This study was conducted to evaluate ...
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Wastewaters from different industries contain great amounts of heavy metals which can contaminate the ground water after entering the soil. Few studies have been conducted on the application of clay minerals such as sepiolite in preventing the leaching of these elements. This study was conducted to evaluate sepiolite as a strong and inexpensive adsorbent in preventing the leaching of lead and zinc from sandy soil columns under laboratory conditions. Therefore, 400 ml of solutions containing lead and zinc with a concentration of 75 mg/l, were passed through pre-saturated soil columns with different amounts of sepiolite (2, 4, 6 and 8 weight percent) in two sizes, < 2 and 20- 50 microns, under a flow rate of 1.2 liter h-1. The concentration of lead and zinc in the successive 20 ml leachate was then measured using atomic absorption spectrophotometer. Results showed that application of sepiolite in soil columns decreased leached amount of Pb and Zn as compared to control treatments. Also, with increasing sepiolite application rate, and decreasing its particle size, leaching of zinc and lead from the soils was reduced. However, the amount of lead leached was less than that of zinc. It seems that sepiolite mineral could be utilized as suitable materials to reduce the leaching of lead and zinc from soil to ground waters.
Volume 37 - Issue 1
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 13-22
Abstract
This study was conducted among dates’ packinghouse workers with the objectives of a) determining of MSDs prevalence and b) evaluating level of exposure to MSDs risk factors. The results of this study can be used to develop MSDs preventive strategies in the workplace and improve workers’ health. ...
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This study was conducted among dates’ packinghouse workers with the objectives of a) determining of MSDs prevalence and b) evaluating level of exposure to MSDs risk factors. The results of this study can be used to develop MSDs preventive strategies in the workplace and improve workers’ health. This study was a descriptive- analytic approach performed on 98 workers at 6 activities and 29 working postures by using REBA method. The prevalence of MSDs was obtained by using Nordic Musculoskeletal Questionnaire (NMQ). The data were analyzed by independent t-test, Chi-square and proportions test with P<0.05 as the limit of significance. The average of age and job tenure was 34.9±14.86 and 7.01±5.79 years, respectively. The 69.4% of the workers suffered from some kind of symptoms during the last 12 months. The highest prevalence was reported in lower back (30.6%), knees (25.5%) and ankles/feet (23.5%). The result of REBA evaluation method showed that 19 postures were at average risk and in need of necessary corrective action and 4 postures were at high risk and possible correction actions were necessary. This study demonstrated that WMSDs occurred at a high rate in the study population. Major ergonomic problems were found to be awkward postures, manual material handling, back rotation and bending. Furthermore, based on the REBA results, implementation of interventional corrective measures to reduce level of workers' exposure to WMSDs risk factors was essential.
Volume 34 - Issue 1
E. Zangene Usefabadi; M. Behzad; S. Boroomand Nasab
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 13-28
Abstract
Transmission of water through a magnetic field will cause some changes in water characteristics, affecting the overall behavior of water molecules including increasing solubility of some of compositions and decreasing water surface tension. This study was conducted with the aim of examining the effects ...
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Transmission of water through a magnetic field will cause some changes in water characteristics, affecting the overall behavior of water molecules including increasing solubility of some of compositions and decreasing water surface tension. This study was conducted with the aim of examining the effects of magnetic water on the level of remaining cations and anions of saline soil, in laboratory conditions, in a compeletly randomaized design. Soil with loam silt texture was poured in pipes with the height of 50 cm and diameter of 10 cm while the end of each pipe was closed with a filter paper and a plastic net. By passing water through the magnetic field with different intensities (6500 Gaousses in first magnetic treatment, 8000 Gaousses in second magnetic treatment), leaching was performed alternatively. At the end of the leaching experiment, the experimental soil was divided into three equal depths and amount of cations ana anions was measured. The result of chemical analysis showed that the avrage amount of the remaining sodium of the soil in the first magnetic treatment, 11.7 %, and in second magnetic treatment, 22.8 %, was lower than the controlled treatment. The avrage amount of the remaining potassium of the soil in the first magnetic treatment, 2.8 %, and in second magnetic treatment, 8.5 %, was lower than the controlled treatment. The avrage amount of the remaining calcium of the soil in the first magnetic treatment, 2 %, and in second magnetic treatment, 16 %, was lower than the controlled treatment. The avrage amount of the remaining magnesium of the soil in the first magnetic treatment, 6 %, and in second magnetic treatment, 13 %, was lower than the controlled treatment. The avrage amount of the remaining chlorine of the soil in first magnetic treatment, 14 %, and in second magnetic treatment, 14.7 %, was lower than the treatment. The avrage amount of the remaining sulfate of the soil in the first magnetic treatment, 2 %, and in second magnetic treatment, 5.8 %, was lower than the controlled treatment.
Volume 40 - Issue 2
Energy and Renewable Energies
M. Soleymani; Alireza Keyhani; Mahmood Omid
Abstract
Introduction Replacing fossil fuels with renewable and environmentally friendly fuels is so essential, due to issues such as climate change, increasing fossil fuels prices, energy security and limitations of fossil fuels resources. Alternatives are wind energy, solar energy, geothermal energy, hydropower, ...
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Introduction Replacing fossil fuels with renewable and environmentally friendly fuels is so essential, due to issues such as climate change, increasing fossil fuels prices, energy security and limitations of fossil fuels resources. Alternatives are wind energy, solar energy, geothermal energy, hydropower, biomass and biofuel. Currently, ethanol produced from sugarcane in Brazil or from corn in USA is the most dominant bioufuel in the world. However there is no comprehensive agreement on the environmental benefits of alternative fuels including ethanol. The aim of this study was to conduct a LCA (Life Cycle Assessment) on ethanol produced from sugarcane molasses in Iran and also to compare its environmental impacts with a conventional fossil fuel. Materials and Methods All required data was obtained from Sugarcane Agro-industry and ancillary Industry Development, Karoon Agro-Industry and also from recorded databases. Economic allocation was chosen to allocate emissions between the main product and the byproducts. Also, Simapro software was applied to model and evaluate the life cycle environmental effects in the life cycle of sugarcane molasses based ethanol (from cultivating sugarcane to burn ethanol into the engine). Two different scenarios of ethanol production (existing system and modified system) were considered and the environmental impacts of these two systems were compared with each other. Finally the environmental impacts of whole life cycle of molasses based ethanol were compared to that’s of diesel as a conventional fossil fuel. Results and Discussion Life cycle inventory results showed that electricity, P2O5 and urea respectively had the most negative environmental impacts through the life cycle of molasses based ethanol. Replacing the fossil fuel originated electricity with electricity from renewable resources can have a significant effect on reducing the amount of these negative impacts. Also, producing electricity in the nearest location to the consumption sites will reduce the power transmission losses and consequently reduce these impacts. Since the major share of electricity is used for pumping water to the field, better management of water consumption is so essential. According to the results, in case of emissions, there was significant difference between diesel fuel and sugarcane molasses ethanol in the base scenario. But by modifying the production system and using bagass to produce biogas or electricity (scenario 2), the environmental impacts of life cycle of sugarcane molasses based ethanol would reduce by 10%. Even now, the amount of greenhouse gas (GHG) emission of ethanol is 60% lower than these emissions of diesel fuel. This reduction will reach 70% if wasted bagass in ordinary production system is used to produce biogas and electricity. Comparing with diesel fuel, Molasses based ethanol had less negative impacts on impact categories such as Respiration Inorganics, Climate Change, Acidification/Eutrofication, and fossil fuels and more negative impacts on categories such as Land Use and Carcinogens, only because of using land and also using herbicides and pesticides to cultivate sugarcane. Greenhouse gas emission in the life cycle of one mega joule molasses based ethanol, estimated by Biograce model, is respectively 69, 70 and 60 percent lower than that of gasoline, diesel and natural gas. Due to undeveloped industries to process sugarcane and its byproducts in Iran, studies on the production of ethanol from molasses or electricity from bagass are in the area of waste management. Therefore, in these cases, even if it there was suitable energy or environmental indicato, continuing the production of these products is justified according to other side issues including environmental benefits and employment. Conclusion In terms of environmental aspects, in the current situation there are no significant differences between ethanol and diesel. But if bagass is used to generate electricity, the environmental impact of ethanol production will reach reduced by 10%. Greenhouse gas emissions of ethanol is 60% lower than that of from diesel and this amount will be 70%, if wasted bagass is used to produce biogas or electricity. It is possible to obtain more environmental benefits by applying appropriate management strategies in ethanol production system (such as producing value added products from bagass or other waste materials). Since sugar is the main product in sugarcane industry in Iran and approximately all other byproducts are wasted, to prevent the loss of this valuable byproduct, producing ethanol from molasses, even if in current situation and with current production system is acceptable.
Volume 42 - Issue 1
Soil Chemistry and Pollution
Narges sousaraeS; Mojtaba Baranimotlagh; Farhad Khormali; Esmaeil Dordipour
Abstract
Introduction Biochar is a charcoal, pyrolyzed from a wide range of carbon-rich biomass materials, such as crop and wood residues, animal manures and a range of industrial wastes and once added into soil, it can store the soil carbon for a long period, improve the soil structure and increase the crop ...
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Introduction Biochar is a charcoal, pyrolyzed from a wide range of carbon-rich biomass materials, such as crop and wood residues, animal manures and a range of industrial wastes and once added into soil, it can store the soil carbon for a long period, improve the soil structure and increase the crop yield. However, the physical and chemical characteristics of biochars are influenced by the properties of the feedstock and pyrolysis conditions, such as highest temperature treatment and furnace residence time. Considering the large variation in biochar properties, it is not surprising that crop yields vary with different biochars. We investigated the effects of biochars on corn growth in the greenhouse. The specific objectives were (a) to assess whether feedstock properties or pyrolysis temperature are important in preparing of biochar and (b) to quantify the effects of varying biochar characteristics on corn growth and chlorophyll index in a calcareous soil under greenhouse condition. Materials and Methods Biochar was produced from crop residues including rice, cotton and canola. Feedstock was oven-dried before pyrolysis. The pyrolysis process was conducted for 1 h at 10°C min‒1 heating rate to produce biochars at different temperatures of 350 and 700 oC under oxygen-limited conditions. All biochars were ground and passed through a 2-mm sieve before experimentation. Ash content and char yield was calculated and biochar pH and electrical conductivity (EC) were measured using 1:20 solid: solution ratio. The soil used in this experiment was taken from the Research Farm of Gorgan University of Agricultural Sciences and Natural Resources. The soil was air-dried and ground to pass through a 2-mm sieve then analyzed for various soil physico-chemical properties using standard methods. A greenhouse experiment was set up using pots with 5 kg prepared soil. Various treatments comprising of 3 biochars type produced at different pyrolysis temperatures (350 and 700°C) from three crop residues (rice, cotton and canola) at three application rates (0, 2 and 5% w/w). A completely randomized design was used in factorial arrangement and treatments were replicated four times. After the soil had been prepared and biochar added, six seeds of maize were planted approximately 20 mm deep in the center of the pots and thinning to seedlings of four plants pot‒1 was done at plant establishment. Distilled water was used to maintain moisture contents of the soil in all the pots during the experimental period. Plant stem and leaves were harvested 96 days after planting. Washed with distilled water then dried with tissue paper. The leaf and stem samples were air-dried and then oven dried at 65˚C to a constant weight in a forced air driven oven. The studied traits included leaf and stem fresh and dry weight, plant height, number of leaves, time to first flowering, chlorophyll index (SPAD), concentration of chlorophyll a, chlorophyll b and total chlorophyll. The analysis of variance (ANOVA) with the factors biochar type, application rate and pyrolysis temperature were performed using a completely randomized design. Significantly different treatment means were separated using least significant difference (LSD) test at PResults and Discussion The results showed that pyrolysis temperature significantly influenced the measured chemical properties of biochars. EC values were tended to increase with pyrolysis temperature. The pH of the biochars was also influenced by temperature. Biochars pH ranged from 6.8 to 9.6. The pH of the biochars was increased with increasing temperature and highest pH (9.6) was observed at 700°C of rice residues. These increases in pH values are mainly due to separating of alkali salts from organic materials by increased pyrolysis temperature. The results showed that the yield of biochars was reduced by increasing pyrolysis temperature and ranged from 19.4% to 40.1%. This decline in yield content is mainly due to the destruction of some compounds such as cellulose and hemicellulose as well as combustion of organic materials with increased pyrolysis temperature. By contrast to biochar yield, the biochar ash content increased with increasing pyrolysis temperature. The lowest values of leaf and stem fresh and dry weight was observed at 700°C of canola residues. These results suggest that biochar produced at high pyrolysis temperature (especially at 700°C), when applied to the soil, may increase soil salinity and subsequently provide undesirable impacts on the plant growth. It has been reported that the negative impacts of high salinity on the plant growth could be due to the following reasons: (1) the low osmotic potential of the soil solution, resulting in water stress, (2) specific ion effects, resulting in salt stress, and (3) nutrient imbalances. Addition of each three types of biochars caused a significant increase in chlorophyll concentration compared to control. Conclusion The type of feedstock material is an important factor that determines the final application of the biochar and its effect on plant growth papameters. Therefore, there is further need for research focusing on the effects of biochar addition on soil properties and plant growth in order to assess biochar as a valuable resource for agriculture.
Volume 33 - Issue 2
Volume 38 - Issue 1
M Alizadeh; M Chorom; N Enayatizamir
Abstract
Introduction: After salinity, drought is of the most common environmental stress for plants in the world and a significant proportion of natural ecosystems and agricultural world is located under salt stress. In general, preventing plant growth of salinity may be due to improper plant photosynthesis, ...
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Introduction: After salinity, drought is of the most common environmental stress for plants in the world and a significant proportion of natural ecosystems and agricultural world is located under salt stress. In general, preventing plant growth of salinity may be due to improper plant photosynthesis, and stomata closure due to the limitation of carbon dioxide is absorbed. Previous studies have shown an increase in the electrical conductivity of the soil with microbial biomass, microbial respiration, and plant residue decomposition rate is negative. The results of studies have showed that the organic matter in soils with high salinity levels even with low vegetation can cause grow the microbial populations resistant to salinity, rapidly. Therefore, the increase residual plants enhance the activity of soil microbes which are beneficial to decompose and release carbon dioxide, nitrate and other ingredients. In arid and semi-arid lands soil organic matter in the soils is generally poor, because of the high temperature maintain and preserve organic matter in these soils is very difficult. Although the use of mineral fertilizers is apparently the faster way is to maintain soil fertility, but the high cost of fertilizer, and cause soil pollution and environmental degradation, is unfavorable act. The aim of this study was to evaluate the effect of plant residues on soil microbial characteristics such as carbon, nitrogen and phosphorus biomass influence on barley plant growth at different levels of soil salinity. Materials and Methods: To make salty soil 40 liters of salinity effluent collected with EC about 33.4 dS /m and after the initial analysis, was diluted and three levels of salinity (2, 4, 8 dS m) were created. After preparing the soil with 3 levels of salinity (2, 4, 8 dS/m), 2 types of debris from wheat straw and alfa alfa (2 levels, zero and 100 g per pot) with 3 replications (total of 36 pots) were prepared. After cultivation of barley seeds, the pots were irrigated. The experiment was conducted in a completely randomized design in a greenhouse. Wet pots were kept at 60 percent of field capacity and irrigation was done by weight. To evaluate the plant's response to the effects of crop residue added at the end of the experiment, after 60 days, shoot and root samples were collected. All samples of barley leaves and stems of the plants were collected two months after planting. The amount of chlorophyll by chlorophyll meter was measured manually by Spad units. Plant height was determined by ruler from the surface to the end of the cluster. For the measurement of pH and EC plant debris from shattered remnants extract ratio (1: 8) was used. Carbon and nitrogen biomass by fumigation extraction method was measured. Results and Discussion: Effect of salinity and crop residue application on barley plant height was significant at 1% level. But, there was no significant interaction between salinity and treated straw. The effect of wheat residue treatment was significant on plant height, but showed a decreasing trend with increasing salinity. Comparison of means of salinity levels showed the greatest reduction in leaf area in 3 salinity levels of the treated straw and the lowest was of the hay treatment. The comparison of means of salinity levels showed that the treated straw had the lowest chlorophyll compared to other treatments. The effect of the addition of plant residues in different levels of salinity on microbial biomass carbon was significant at 1% level. Adding mineralization of organic waste leads to increased precursor enzymes and microbial growth increases. The results showed that moderate amounts of carbon, nitrogen and phosphorus microbial biomass was affected by increasing salinity in reverse. The amount of phosphorus added to the soil was deeply influenced by phosphorus ratio of carbon to biomass and biomass is phosphorus. P ratio of carbon to biomass increased by reducing the availability of phosphorus. Changes in the ratio of carbon to microbial biomass P refers to changes in microbial communities in soil. Reduced microbial biomass carbon in soils containing straw because of organic compounds toxic like phenols produced the soil micro-organisms. Increased alfalfa and crop residue as organic fertilizer to the soil salinization significantly affects the microbial biomass nitrogen. Comparison of the results showed that microbial biomass phosphorus in 3 salinity levels was, at 1%, significantly different from control and treatment straw and in between treatments; alfalfa treatment significantly increased microbial biomass phosphorus. Conclusion: The results indicated that salinity reduced height, leaf area and plant chlorophyll content of barley. Added plant residues at different levels of salinity, while increasing soil organic matter and soil microbial, somewhat affected the barley crop yields. This effect was different depending on the type and quality of plant residues. Hay debris due to available nutrients, especially nitrogen and phosphorus, reduced soil salinity, and crop yield was somewhat increased, but the impact of wheat residues was not observed on the plant atmosphere. The results also showed that with increasing salinity of soil, microbial indexes such as microbial biomass carbon and nitrogen was decreased.
Volume 34 - Issue 2
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 15-28
Abstract
In order to investigate the effect of Sewage Sludge (SS) application on the amount of micro elements in soil and absorption of these elements in plant organs of medical plants mint (MenthaPipperata), an experiment was carried out in split plot based on a complete randomized block design in three ...
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In order to investigate the effect of Sewage Sludge (SS) application on the amount of micro elements in soil and absorption of these elements in plant organs of medical plants mint (MenthaPipperata), an experiment was carried out in split plot based on a complete randomized block design in three replications in the field of the University of Agricultural Sciences and Natural Resources of Sari. Five levels of fertilizer treatments (T1= control, T2= 20 tons per hectare mix SS and 1/2 fertilizer, T3= SS 20 tons per hectare, T4= 40 tons per hectare mix SS and 1/2 fertilizer and T5= SS 40 tons per hectare) and six levels of fertilizer years one year fertilizer (1385), two unconsecutive years fertilizer (1385 and 1387), two consecutive years fertilizer (1385 and 1386), three unconsecutive years fertilizer (1385, 1386, 1388), three consecutive years fertilizer (1385, 1386 and 1387) and four consecutive years fertilizer (1385, 1386, 1387 and 1388) were considered. The fertilizer treatments were carried out before planting in the land. The results of these tests showed that as the level of consumption and Sewage Sludge increased, the amount of absorbent micro-elements in the soil and the concentration of these elements in the mint plant increased. Most of too the micro-dements were observed in the 40 tons/ha treatment of SS in three consecutive years with more consumption compared to others. The interaction between the years of fertilizer consumption and fertilizer treatment on the rate of absorbent micro-elements except Mn in the soil and root of mint were significantly different, where, as, in the plant leaves, the interactions had a significant effect on the amount of Mn, but no significant effect was observed in the absorption rate of Cu, Fe and Zn.
Volume 40 - Issue 1
H. Tazikeh; F. Khormali; A. Amini; M. Barani Motlagh
Volume 41 - Issue 4
Soil Chemistry and Pollution
Somayeh Sefidgar shahkolaie; Mojtaba Baranimotlagh; Farhad Khormali; Esmael Dordipour
Abstract
Introduction At present, contamination of water and soil resources is an important environmental challenge. Therefore, decontamination of such is a prerequirement for using these resources. Cadmium (Cd) and lead (Pb) often coexist in contaminated soils and there is currently no effective means for their ...
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Introduction At present, contamination of water and soil resources is an important environmental challenge. Therefore, decontamination of such is a prerequirement for using these resources. Cadmium (Cd) and lead (Pb) often coexist in contaminated soils and there is currently no effective means for their concurrent removal. Concerns about their mobility and bioavailability have increased because of food safety, potential health risks and its detrimental effects on the ecosystems. The stabilization/solidification is a cost effective remediation method that prevents spreading of heavy metals in soil and water resources. In this process, contaminated soil reacts with amendments such as organic and liming materials to form low soluble or non-soluble stable materials. The objective of this study was to evaluate the effect of several low cost amendments on Cd and Pb stabilization by a sequential extraction method. Materials and Methods In this research, in order to investigate the effect of organic amendments (biochar 640°C, and biochar 420°C) and inorganic amendments (Pumice, Leca, Zeolite, and Bentonite) on Pb and Cd stabilization in a contaminated soil, an incubation experiment was carried out. One kilogram of each amended soil and the control soil were packed into respective pots. Soils were amended in the laboratory using biochar 640 (BI1), biochar 420 (BI2) bentonite (BE), pumice (P), leca (LE), and zeolite (Z). A control treatment (C) without adding amendment was also prepared. The amendment materials were applied at 1 and 5 percent wt. Each treatment was performed in three replicates and the samples were incubated in the dark at 14°C for 6 months. At the end of the incubation time, the potential bioavailability of Cd in non-amended and amended soils was evaluated by extraction with DTPA and ethylenediamine tetraacetic acid (EDTA). Total Cd (CdT) and Pb (PbT) was extracted by aqua regia (HNO3 + HCl) extraction. The chemical fractions of Cd and Pb were determined by a sequential extraction method which is a five-step chemical fractionation based on the work of Tessier et al. (1979). All statistical analyses were performed using SAS software. Means of different treatments were compared using LSD (P ≤0.05) test. Results and Discussion The results indicated that the additions of amendments to soils reduced the concentration of DTPA and EDTA-extracted Pb and Cd. The smallest concentration of Pb-extracted DTPA and EDTA was observed in organic amendments treated soil (biochar 640°C, and biochar 420°C) and treated with 5% biochar 640°C, respectively. The high sorbent capacity of the BI used in this study could be due to its high pH, high content of organic carbon and cation exchange capacity (CEC). The highest decreasing rate of DTPA and EDTA-extractable of Cd was observed in treated with 5% pumice and zeolite, respectively. Application of the amendments (except for 1% LE) decreased exchangeable fraction (F1) of Pb compared to the non-amended soil. Also, the amendments (except for 1% P, Z and BE) decreased exchangeable fraction (F1) of Cd compared to the non-amended soil. Although the biochar 640 (5%) showed the highest decreasing rate of exchangeable fraction (F1) of Pb and Cd, they increased the oxide (F3) and organic (F4) fractions, which might be due to its rich O-containing functional groups and high alkalinity leading to an increase in the binding of Cd and Pb to organic compounds and mineral oxides. Conclusion Results indicated that application of amendments was successful in lowering the potential bioavailability of Pb and Cd soils. The 5% biochar 640 treatment had the greatest decrease in extractable Pb. Also, the 5% zeolite and pumice treatment had the greatest decrease in extractable Cd. Application of BI resulted in a significant decrease in both Pb and Cd exchangeable fraction (F1). This reduction in the exchangeable fraction (F1) of Cd and Pb in the soil was due to an increase in the fraction of heavy metals bound to the soil organic matter (F4) oxides (F3) after BI addition. Enhanced precipitation or co-precipitation and complexation of metals with amendments led to the reduction of the solubility of the metals. The P, LE, BE, and Z altered the exchangeable fraction (F1) of Cd and Pb to the oxide fraction (F3) and the carbonate fraction (F3), respectively. Application of BI amendment causes the highest decreasing rate of solubility Cd and Pb, suggesting this as the suitable amendment for the remediation of Cd and Pb in contaminated soils.
Volume 42 - Issue 4
S. Rostami; B. Hosseinzadeh; O. Bahrami
Abstract
Introduction Clutches are widely used in various vehicle powertrains system. Unlike cars, tractors use a dual clutch system for smooth operation of the external power takes off shaft. The dual clutch system allows the operator, while working with an implement, to change gears without affecting on the ...
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Introduction Clutches are widely used in various vehicle powertrains system. Unlike cars, tractors use a dual clutch system for smooth operation of the external power takes off shaft. The dual clutch system allows the operator, while working with an implement, to change gears without affecting on the operation of implement. When the pedal of clutch is fully pushing, the drive was be interrupted in transmission system and PTO shaft. Because the torque of the tractor’s engine is more than the car’s engine, the extra force is be need to hold the tractor’s clutch. The nature of tasks on a tractor, necessitates a number of actions to be performed by the operator, which puts varying physiological demands on his body. Examples of these tasks are: steering of the tractor, looking backward to observe and control the machine/implement, and force required to operate the clutch, brake, and hydraulic control system. This tasks and workplace, was determines the postures and load distribution on the body structures of the operator. Pedals are one of the most important controllers used in vehicles. Dupuis (1995), reported that a driver pushes the pedal of clutch 230 times per hour on average. Lehmann (1958), pointed out, that the force is exerted on the pedal generally is far greater than the required force. If the force exerted on the pedal is high, the driver cannot detect the moment that the clutch is actually released. Forasmuch as, the clutch is operated by a leg force, and it is mounted on the left side of the tractor driver. Then it’s more important to use a mechanism to amplify the force that applied on the clutch by the driver. use a booster is an appropriate way to amplify the force. Materials and Methods First of all, before installing the booster, the force required for pushing the clutch was calculated. Keeping in mind that no change should occur on the tractor body and pedal position. Then, the booster was installed between the clutch pedal and clutch plug lever. Since the force from clutch to clutch plug lever is tensional, the booster was initially in compression, the direction of the force attached to the clutch was changed using a lever. The direction of resulting force from booster was changed using another lever that to be applied to the clutch plug lever. In order to, providing vacuum for booster, the booster’s vacuum chamber was connected to the engine’s input manifold by a plastic tube. Forty experiments were conducted to calculate the requirement force for pushing the clutch. These experiments were carried out for 5 engine speeds (800,1100, 1400, 1700 and 200 rpm), and 8 inlet diameters of manifold (15, 20, 25, 30, 35, 40, 45 and 50 mm). Experiment was repeated 3 times. Finally, the mean results from three experiments was considered as the true value for each experiment. A load cell (ZEMIC (H3)) was used to calculate the force required for pushing the clutch and data of each experiment was saved in computer distinctively. For measuring the suction in connecting tube that placed between the booster and air manifold, the water column upwelling method was used. Results and Discussion Results of analysis of variance shows that the interaction effect of inlet diameter × engine speed and force, as well as, interaction effect of inlet diameter × engine speed and suction was significant (P <1%). This means that by increasing the engine speed and decreasing the inlet diameter of manifold, more air is sucked in, and therefore, the pressure inside the manifold was be reduce. by decreasing the pressure in the manifold, the difference pressure on both sides of the booster diaphragm was increased, and cause increasing the auxiliary force of booster, thereby, the force required to press the pedal was reduced. Maximum reduction on the force required to push the pedal by using this system is about 170 N, that occur in 15 mm inlet manifold diameter and 2000 rpm engine speed. Conclusion In this paper, a brake booster was installed on the MF285 clutch to reduce the force required to push the clutch pedal. It was observed that this force was about 33.6 kg in the normal state while by using of this system, the required force was reduced to 26 kg.
Volume 33 - Issue 1
Volume 43 - Issue 1
Mehdi Karimi; Mohammad Zaremehrjardi
Abstract
Introduction Annually around 2 million tons of nitrogenous fertilizers is used in Iran. It was reported that increasing trend of chemical fertilizers application over the last 30 years with some fluctuations. So, proper fertilizer management in Iran has great effect on soil and water quality. Salinity ...
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Introduction Annually around 2 million tons of nitrogenous fertilizers is used in Iran. It was reported that increasing trend of chemical fertilizers application over the last 30 years with some fluctuations. So, proper fertilizer management in Iran has great effect on soil and water quality. Salinity stress is known as a worldwide abiotic stress responsible for reduced crop production. It is estimated that annual losses of yield due to salt induced land degradation is US$ 27.3 billion globally. Social and economic dimensions of salinity stress can be employment losses as well as environmental degradation. In addition, it is well documented that application of chemical fertilizers usually improve plant performance under saline conditions but results in plant fertilizer requirement under salt affected soils are contrary. While there is little evidence of yield benefits due to application of fertilizers in salinized fields at rates beyond optimal in non-saline conditions, there is enough evidence indicating that soil salinity does not affect or decrease plant fertilizer needs. It is well documented that salinity stress negatively affects wheat growth rate and it postpone the ripening in wheat plants. While flowering happened at 59. 33 days after planting at non-saline conditions, it occurred 62.22 days after planting for salt affected plants. The negative effect of salinity on wheat nitrogen content is reported. This is due to the negative effect of salinity stress on root growth and the chloride on nitrogen uptake. A hypothesis that salinity stress can adversely affect nitrogen uptake pattern of wheat has been proposed, but, contradictory results have been reported. Thus nitrogen fertilizer management may need to be modified under arid and semiarid conditions of Yazd province with wide range of irrigation water qualities. Accordingly, the objectives of this field study were to elucidate the effect of salinity stress on nitrogen uptake pattern and nitrogen timing in wheat. Materials and methods A field experiment was conducted on wheat at Sadooq Salinity Research Station, Ashkezar, Yazd, Iran. Mean annual temperature is 18°C and precipitation is 70 mm. The treatments, nitrogen fertilizer sources (ammonium sulphate and urea) and three irrigation water qualities (1.7, 7.22 and 12 dS m-1), arranged in a randomized block, split plot design with three replications. Consisting 20 rows of wheat, each field plot was 6*4 m. All plots received common agricultural practices including tillage and fertilizer application. Regarding typical recommendations and guidelines for this region and soil type, all fertilizers, except urea that applied in 2 splits, were soil-applied before planting. Nitrogen was applied at a rate of 105 kg ha-1 at two stages (90 and 120 days after planting). As soil phosphorous and potassium content was above threshold level, these elements were not applied for wheat production. Plant samples were provided at four growth stages including tillering, stem elongation, flowering and harvest. The samples were analyzed for nitrogen content. Plant nitrogen content was determined using kjldal method. The analysis of variance for different parameters was done following ANOVA technique. When F was significant at p ≤ 0.05 level, treatment means were separated using DMRT. Results and discussion The soil at the experimental site was calcareous with 31.5% total nutrient value, sandy loam texture, high pH (8.06) and low organic carbon (0.51 %). The results showed that wheat top yield depends on irrigation water salinity level as well as nitrogen management. While a sigmoidal trend in wheat top yield for all treatments observed over time, increasing irrigation water salinity from 1.7 to 7.22 and 12 dS m-1 decreased wheat yield at harvest from 11058 to 7183 and 7933 kg ha-1. In other words, salinity stress significantly decreased wheat performance by 35.04 and 28.26 percent. The results also showed that nitrogen content decreased over time. While nitrogen content was more than 5 percent at tillering it decreased to 1 percent at harvest. Nitrogen uptake was not affected by nitrogen source but it was affected negatively by irrigation water salinity. Depending on salinity levels and the application rate of nitrogen, nitrogen uptake by wheat ranged from 81 to 189 kg ha-1. However, nitrogen uptake was not affected significantly by nitrogen sources. Conclusion Overall, it was concluded that salinity stress did not affect nitrogen uptake pattern of wheat under field conditions of the experiment. As more than 80 percent of nitrogen was uptaken from mid tillering onward, it is recommended that just only 15 percent of nitrogen fertilizer be applied at planting. This would increase nitrogen uptake efficiency and prevent soil, water and air pollution.
Volume 36 - Issue 2
Atefeh Esmaili Dastjerdipour; Mohammad Farpoor; Mehdi Sarcheshmehpour
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 17-35
Abstract
Cyanobacteria play an important role in providing biological soil crusts in sandy soil of desert areas. The aims of the present research are to investigate the possibility of crust formation under three cyanobacteria (Nostoc. sp (N), Phormidium.sp (Ph) and combination of two genus (Ph + N), two polymer ...
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Cyanobacteria play an important role in providing biological soil crusts in sandy soil of desert areas. The aims of the present research are to investigate the possibility of crust formation under three cyanobacteria (Nostoc. sp (N), Phormidium.sp (Ph) and combination of two genus (Ph + N), two polymer treatments [blank (S0) and 0.3 g per 250 g soil (S1)] and two moisture levels [FC (M1) and 80% FC (M2)] in three separated parts. Crust thickness, increase in soil organic carbon and resistance to penetration of crusts after complete coating (60 days) were measured in the first part of the experiment. Then the effects of time (15, 30, 45 and 60 days) on crust thickness and micromorphological investigations of crusts were performed in the second and third parts of the experiment respectively. Results of the study showed that simultaneous application of two genus at FC level with polymer creates the thickest (6.83 mm) and the most resistant crusts (0.27 MPa) to penetration. Both cyanobacteria genus with polymer and FC level caused the highest organic carbon contents (1.89% and 1.66% respectively). Also the thickest crust (6.8 mm) was formed by simultaneous application of two genus during 60 days. Micromorphological observation showed decrease in macro pores in treated samples compared to control and this decrease of pore space size with application of both cyanobacteria genus was higher than each of them alone.
Volume 37 - Issue 2
E. Asgari Asli Ardeh; M.J. Sheikh Davoodi; Z. Basati; N. Babamiri
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 17-31
Abstract
The aim of this research was to investigate the effect of grain soaking time (at two levels in 2 and 4 days), grain soaking temperature (at two levels 10 and 25 °C) and grain final moisture content (at three levels 8, 11, 14%w.b.) on the percentage of broken grain during husking and whitening processes ...
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The aim of this research was to investigate the effect of grain soaking time (at two levels in 2 and 4 days), grain soaking temperature (at two levels 10 and 25 °C) and grain final moisture content (at three levels 8, 11, 14%w.b.) on the percentage of broken grain during husking and whitening processes for three paddy rice varieties (Hashemi, Hasani and Khazar) which are common in Guilan Province. The results revealed that the effect of main factors and their intractions was significant on the broken grain percentage during husking and whitening processes. The Hashemi variety had the highest broken grain with values 42.99% and 38.48% at husking and whitening processes, respectively. By increasing grain soaking time from two to four days, broken grain mean values at husking and whitening processes decreased significantly from 20.23% to 15.59% and 29.53% to 27.19%, respectively. By increasing soaking temperature from 10 to 25 °C, broken grain mean values at husking and whitening processes decreased significantly from 19.26% to 16.57% and 29.64% to 27.38%, respectively. The increase of final grain moisture content from 8 to 14%w.b. caused a significant decrease of broken grain at husking from mean value 21.39% to 14.88% and a increase significant in broken grains at whitening from mean value 25.91% to 31.05%. Comparison of the mean results of quaternary interactions showed that the least broken grains percent of husking process (4.736%) was obtained at test with Hasani variety, soaking time of four days, soaking temperature of 10°C and grain moisture content of 14 (%w.b.). Also, the hightest broken grain percentage of husking process (56.8%) was obtained at test with Hashemi variety, the soaking time of two days, the soaking temperature of 10 °C and the grain moisture content of 8 w.b.%. The least broken grain percentage of whitening process (9.44 %) was obtained at test with Khazar variety, the soaking time of four days, the soaking temperature of 25 °C and the moisture content of 11 w.b.%. The highest broken grain percentage of whitening process (57.85%) was obtained at test with Hashemi, soaking time of 2 days, soaking temperature of 10 °C and grain moisture content of 14%(w.b.).
Volume 39 - Issue 2
Energy and Renewable Energies
M Rekabi; M. H Abbaspour Fard; H Mortezapour
Volume 41 - Issue 1
Soil Physics, Erosion and Conservation
Motahareh Noorzade Roshan; Reza Ghorbani Nasrabadi
Abstract
Introduction Soil quality has been defined as a “The potential of soil to play a positive relationship with the other parts of ecosystem”. Soil biological indicators provide insight into the living component of the soil. Similar to physical and chemical indicators, biological indicators have ...
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Introduction Soil quality has been defined as a “The potential of soil to play a positive relationship with the other parts of ecosystem”. Soil biological indicators provide insight into the living component of the soil. Similar to physical and chemical indicators, biological indicators have a relationship to soil functions and can evaluate soil functions to assess soil quality. Between biological indicators, an index that can be measured quickly and easily is more useful to show the changes. In many studies an indicator of microbial respiration, microbial population, nitrogen mineralization and enzymes activity can be used. Special ability is required to measure quickly and show the quality of soil microorganisms and reaction to environmental changes. Soil health is defined by chemical and physical parameters such as soil texture, soil pH, electrical conductivity, etc., that are not quantifiable completely. Therefore, conservation practices planting and forestry may directly or indirectly affect a organism’s activities. The results of land-use systems without consideration of the consequences on soil quality have been environmental degradation. Agricultural management systems have been generally adopted without attending to soil conservation and soil quality, and this therefore causes significant decline in agricultural soil health worldwide. Different methods of soil conservation have been proposed to prevent erosion and improve soil quality destructive phenomena. In Golestan province due to topographical and climatic conditions and less soil sensitivity to erosion, more attention should be given to this issue. But it remains unclear how far this conservation practice can take to prevent damage. This study aimed to investigate the role of conservative practices to improve the soil quality indicators.Materials and Methods The watershed of Chehelchai is located between North latitudes 36° 59´ and 37° 13´ and Earth longitudes 55° 23´ and 55° 38´. The history of land use in the region shows that more than about 40 years ago, all the study area was covered by forest. Agricultural land use changes occurred on a large scale. With emphasis on conservation operation, parts of the agricultural land were changed to productive gardens, partly forested, partly pasture with native species. Different land uses were selected in loess formations, and slope of 41 %, with life operations was about 6 to 7 years. Protective Operations Garden species, terraces and forestry were selected and quality of soil was compared with agricultural land, pasture and natural forest. In this regard, 10 soil samples were taken. After preparation of the samples, physical, chemical and biological analysis were measured. Additionally, soil properties (pH, Electrical Conductivity, Calcium carbonate, organic matter, texture, bulk density, aggregate stability, microbial respiration, microbial biomass population count of micro- arthropods, biological soil quality) were analyzed. The data were analyzed using software SAS. Ver 9. and the results were compared in a randomized complete block design. Analysis of variance in the form of randomized complete block design was done using the LSD multiple comparison. Results and Discussion Our results showed that the dominant soil texture class in land uses was silty loam. It seems that soil texture is less affected by the land use changes. The results showed that the changes of forest and pasture to agricultural lands have destroyed the soil quality. Soil quality indicators such as organic matter and aggregate stability have declined by 60 and 70 percent respectively. Like wise, biological indicators such as microbial respiration, microbial biomass carbon and QBS (biological soil quality indicators based on the population of micro- arthropods) and EMI (index dependence of soil to soil organisms) showed a similar trend. In contrast, the Conservation practices improved the indices. Biological indicators in the forestry and gardening showed an increase of 40 percent in EMI Microbial biomass carbon and 80 percent in microbial respiration. Terracing had less improvement than other operations in about 11 to 20 percent in EMI and microbial biomass carbon. Conclusion Conservation operations had fewer effects on indicators such as aggregate stability and organic matter. Under estimation of effects in certain indicators maybe due to short time of conservation practices. It seems that these operations will show better results in the future Received: 19 July, 2016Accepted: 10 April, 2018
Volume 41 - Issue 3
Soil, Water and Plant Relationships
Javad Zamani; Mohammad Ali Hajabbasi
Abstract
Introduction Due to the difficulties in observing root growth in soil, our knowledge regarding soil-root system is limited. The roots are the hidden half of the plants but our knowledge of root’s growing is limited. Now, there are some methods and devices that have been used to analyze and monitoring ...
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Introduction Due to the difficulties in observing root growth in soil, our knowledge regarding soil-root system is limited. The roots are the hidden half of the plants but our knowledge of root’s growing is limited. Now, there are some methods and devices that have been used to analyze and monitoring roots architecture and growth and their relation with soil. The assessment of the root growth of plants is possible with some photographic techniques such as neutron radiography and tomography, as well X-Ray imaging, but the use of these methods for root studies is very costly especially in Iran. The use of the rhizotron can also be one of the most practical and cost effective methods. The rhizotron is a box with a transparent side and uses to study the roots growing by photography or drawing roots on transparent acetate sheets. Here we aimed to introduce the rhizotron as a technique for studying plant roots, and conducted this study to investigate the effects of heterogeneous petroleum pollution in soil and endophytic fungus on growth and distribution of maize root. Materials and Methods In order to bring rhizotron forward as a method for in situ assessment of growth, establishment and distribution of plant roots a greenhouse experiment was performed. The effect of Piriformospora indica and soil petroleum polluted layers on the growth and distribution of maize (Zea mays L.) roots was studied. The rhizotrons had a wooden frame and back plate, and a removable front cover made of a 4 mm thick glass plate. The inner space was 30 cm high, 20.5 cm wide, and 1.5 cm thick (Figure 1a). The rhizotrons were placed on a rack with a 45˚ inclination to induce roots growing along the front glass to enable visual growth monitoring. The front glass plate was covered with an opaque black plastic to prevent light entering except for the times of observation. Two different patterns of soil-petroleum contamination layering were generated in the packings of the rhizotrons. 1) a shallow layer of 2.5 cm thick petroleum-contaminated soil, underlying of a 2.5 cm and above a 22.5 cm layer of uncontaminated soil (NSC), and 2) 27.5 cm of uncontaminated soil (‘control’). The packing procedure was layer by layer using uniform filling in all three cases. The contaminated soil layers were covered with a 2.5 cm layer of uncontaminated soil in order to facilitate plant establishment. The experiment with three replications was included as the packing methods each for growing maize plants inoculated with and without P. indica, and plant-free controls. The root development was recorded 12, 16, 22, 26, 33, and 45 days after transplanting by tracing all roots that were visible through the front glass on acetate transparencies, then were scanned at 300 dpi and analyzed for parameters such as root length, number of root tips and depth of rooting using the SmartRoot plugin of the software package ImageJ. After the last recording, the experiment was terminated. Roots and shoots were separated after harvesting, weighed and oven-dried. Rhizosphere soil samples were taken from the layer 2.5–5.0 cm below the soil surface for total petroleum hydrocarbons analysis. Results and Discussion The results well showed that root length, root depth and number of root tips could be monitored by this method. The presence of petroleum pollution in the soil significantly decreased the growth and distribution of roots but inoculated plants had more root length and root depth than uninoculated plants. The number of root tips which representing lateral distribution of roots had similar trend with root the length and they were significantly increased in the inoculated plants as compared with uninoculated ones. Results showed that inoculation of maize by P. indica increases root biomass more than the aboveground biomass. Conclusion Despite the limitation in the study of the effect of soil treatments on the growth and distribution of plant roots, the use of rhizotron could be a technique to solve this limitation. Our study proved that by using of rhizotron we can show the growth and 2-dimension distribution of plant roots, while the effects of treatment and root-soil interaction could also be assessing by this device.
Volume 38 - Issue 2
R. Taghizadeh-Mehrjardi
Volume 42 - Issue 3
H. Mehregan; Sh. Ghavami Jolandan; M. E. Khorasani Ferdavani
Abstract
Introduction Today, in modern agriculture, the use of agricultural machines is inevitable. the tire is the last part of the power transmission system, which plays an essential role in controlling the tractor and transferring the tractor's reaction to the soil. Tires used in agricultural implements and ...
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Introduction Today, in modern agriculture, the use of agricultural machines is inevitable. the tire is the last part of the power transmission system, which plays an essential role in controlling the tractor and transferring the tractor's reaction to the soil. Tires used in agricultural implements and tractors should be able to transport appropriately and have sufficient adhesion and slip. Several parameters affect these abilities, including tire diameter and width, tire shape, tire tread modulus, tire pressure and load on the tire, with the last two parameters, tire pressure and load on the tire two very important factor is the tire and surface contact, the tire's contact between the tire and the ground, the tire's involvement in the direction of travel, as well as the tensile and fuel consumption of cars and motor vehicles. Given the fact that the tire pressures/load of agricultural machinery are less attractive to the users, Due to the many benefits that the use of electronic control systems. Due to the many benefits that the use of electronic control systems, Today, the use of electronic control technologies is considered as an innovation. the automatic tire pressure control system could ensure the pressure stability. Tire pressure drop is detected, and the system automatically refills the tire according to the tire pressure requirements. Therefore, the main aim of this paper is to set the tire pressure at the optimal value by designing an electronic control system for measuring and controlling tire pressure and evaluating the response speed of the system. Materials and Methods This research work is mainly aimed at designing a tire pressure control the tire pressure. BD pressure sensor, Arduino board, voltage/pressure regulator, 5-volt double-channel relay module was utilized. Moreover, Solenoid valve, rotary joint along with compressor and reservoir was employed for controlling tire pressure. In this paper, a laboratory tire pressure control system was designed which can operate in both manual and automatic modes. In automatic mode, a series of ideal pressure (P1) is defined as the soil type, and the driver selects an ideal pressure for the system. If the tire pressure (P0) differs from the set pressure point (P1), then the control unit determines a time duration (T1) for the decrease/increase the pressure level to achieve the optimal setpoint. Besides, a manual mode allows the system to provide a wide range of pressure for the driver depending on the terrain encountered. It is worthy of mentioning that the operation of the system in manual mode is the same as that of automatic mode. In this work, experiments were performed at three levels of output pressure (43.5, 65.2, 87 psi), two tire pressure reduction levels (20- 16 and 16 -12 psi), and two tire pressure increase levels (8 -12 and 12 -16 psi). The tests were laid out as a factorial in a completely randomized design with three replicates. Results and Discussion The ANOVA results indicated that the effect of reservoir outlet pressure on the timing function and tire pressure was significant at the level of 1% (p-value <0.01), while the dual and triple impacts of the factors were not significant. The results also illustrated an increase in the speed of the system response at the output pressure of the reservoir of 87 psi. Also, two different scheduling functions were conducted to evaluate the speed of the system response to reduce the tire two levels of 20 to 16 and 16 to 12 psi. For this reason, two different scheduling functions were used. The ANOVA results indicate that the timing function and tire pressure level had a significant effect on the output parameters at the level of 1%. Furthermore, an increase in the speed of the system response in the second-order scheduling function was observed. Comparison of system performance with first and second time estimation functions at different reservoir pressures, as shown in Fig. 9, showed that the use of the second-order estimation function in all cases reduced the number of steps to reaching the desired pressure significantly. Conclusion According to the obtained results, it can be concluded that the replacement of the second-order scheduling function to control tire pressure, increased the speed of the system’s response, which results in keeping the right pressure at all times very accurately.
Volume 47 - Issue 1
Land Evaluation and Suitability
Nazanin Khakipour
Abstract
IntroductionSoil is a dynamic natural system and interface between land, air, water, and life, which performs vital services for human sustenance. The increasing population growth has led to the excessive use of this natural resource to provide food, clothing and other human needs. This has led farmers ...
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IntroductionSoil is a dynamic natural system and interface between land, air, water, and life, which performs vital services for human sustenance. The increasing population growth has led to the excessive use of this natural resource to provide food, clothing and other human needs. This has led farmers in different parts of the world to improper exploitation of inferior and marginal lands such as pastures and forests located on sloping lands. However, on the one hand, these lands have low potential and on the other hand, they have a high potential for erosion. Soil quality is usually introduced as the ability of the soil to interact with the ecosystem maintain the productivity of the quality of different parts of the environment and thus improve the health of plants, animals and humans. The quality of soil and its importance for the development of sustainable agriculture are more important nowadays. Land use change is one of the most important current problems of our country, especially in the Hyrcanian forest lands in the north of the Iran. The objectives of this study were to evaluate the effects of land use change on some soil quality indicators in north of Iran. Methods and Materials A part area in the south of Lahijan was selected including 3 land uses: Natural Forest (NF), Tea plantation (TP) and paddy rice (PR) cultivation. In each land use 10 soil samples were collected at 0-20 cm depth and transferred to the laboratory. Undisturbed soils samples by core was taken for measurement of bulk density. A part of sample passed through the 4 mm sieve for measurement of aggregate stability and three indices comprised mean weight diameter: MWD, geometric mean diameter: GMD and water stable aggregates: WSA were calculated. Other soil properties such as pH, Calcium carbonate equivalent (CCE), soil organic matter (SOM), particulate organic carbon (POC), and soil respiration also measured.Results and Discussion The statistical results in this study showed that due to the change of land use from forest to tea and rice cultivation, the amount of organic carbon decreased, while the amount of pH and calcium carbonate increased. As a result of changing the use of forest land to other two land uses, the indicators of stability of soil aggregates (MWD, GMD and WSA) have significantly decreased, and as a result, the bulk density of the soil has increased. The amount of MWD was 1.95 mm in the forest, 1.2 mm in the tea plantation, and 0.45 mm in the rice cultivation. The amount of particulate organic carbon as one of the indicators of soil quality in forest lands was observed in the maximum amount. In addition to the reduction of particulate organic matter, this change is also caused by the excessive traffic of machines. Soil microbial respiration was analyzed as a soil biological indicator. The results showed that the average microbial respiration in the natural forest was equal to 300 mg C/ day.g soil, and in the two other land uses of tea and rice cultivation, it was calculated as 200 and 120 mg C/ day.g soil, respectively. Positive and significant relationship between SOM and MWD confirmed that soil organic matter had high contribution for soil aggregate formation and its stability. Conclusion This research was conducted to investigate the impacts of land use changes in the north of Iran in Gilan province on some soil quality indicators. The results of this research showed that the soil’s chemical, physical, and biological characteristics have shown significant differences due to land use change. In forest soils, the highest amount of organic carbon, and the lowest amount of pH was observed, which is due to the high accumulation of organic matter and high leaching of cations. Due to the degradation of organic carbon in the other two uses, the bulk density and aggregate stability indicators have decreased. The intense cultivation operations in the other two uses, especially in the paddy fields, have destroyed the soil structure. Also, more organic carbon in forest soils has led to more microbial respiration. In total, all soil quality indicators have decreased with the change in land use in the study area. Therefore, land conversion and especially deforestation in the studied region should be avoided. In total, the results showed that land use change in the study area has caused land degradation and reduced the soil quality and soil health indicators, and it is necessary to consider it in land use planning, land improvement, and sustainable land management.
Volume 39 - Issue 1
M. Safari; R. Amiri Chayjan; B. Alaei
Abstract
Introduction Almond (Amygdales Communist L.) is a perennial plant growing in the cold and xeric environments of Iran. The kernels of almond form an important source of energy and protein. An infrared- vacuum dryer with microwave pretreatment benefits includes high mass transfer coefficients and high ...
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Introduction Almond (Amygdales Communist L.) is a perennial plant growing in the cold and xeric environments of Iran. The kernels of almond form an important source of energy and protein. An infrared- vacuum dryer with microwave pretreatment benefits includes high mass transfer coefficients and high quality and the appropriate control on dryer conditions. The aim of this study was to evaluate the effect of air temperature, microwave power and vacuum pressure in drying process of almond kernels and calculate the effective moisture diffusivity, activation energy, energy consumption, shrinkage and color changes. Materials and Methods Fresh almond kernels were obtained from a field located in Asadabad (Hamedan Province), Iran and stored in a refrigerator at 4±1˚C for experiments. The initial moisture content of almond kernels was determined by drying of 10 g of sample in an oven at 105±1°C until constant weight was attained. In this study, the drying properties of almond kernels with moisture content of 47% (d.b.) in an infrared- vacuum dryer with microwave pretreatment were investigated. Three levels of air temperatures (45, 60, 75 °C), three levels of microwave powers (270, 450 and 630 W) and three levels of vacuum pressures (20, 40 and 60 kPa) were applied to perform the experiments. Seven mathematical models were fitted to the experimental drying data of almond kernels. Weight loss of samples was measured and recorded every 20 seconds in microwave dryer and every 300 seconds in infrared-vacuum dryer, respectively. Drying time was defined as the time required to reduce moisture content of samples to 0.1 g of water per g of dry mass. Results and Discussion It was observed that increasing the air temperature and microwave power decreased the time required to reach a certain level of moisture ratio. Also, by reducing the vacuum pressure, drying time for almond kernels was decreased. The results showed that the highest values of coefficient of determination were obtained with the Midilli et al. model. The Midilli et al. model gives higher R2 and lower RMSE and . Therefore, the Midilli et al. model may be supposed to demonstrate the drying behavior of the almond kernels in an infrared-vacuum dryer with microwave pretreatment. The maximum value of Deff (5.33×10-9 m2/s) during the experiments was depending on the air temperature of 75˚C, vacuum pressure of 20 kPa and microwave power of 630W. The minimum value of Deff (8.03×10-10 m2/s) depended on the air temperature of 45˚C, vacuum pressure of 60 kPa and microwave power of 270W. Air temperature had a larger effect on the Deff values of almond kernels drying. Minimum and maximum values of activation energy (Ea) for almond kernels were 28.73 and 51.84 kJ/mol, respectively. The highest and lowest values of energy consumption were 0.26 at air temperature of 45˚C, vacuum pressure of 20 kPa and microwave power of 270W and 0.07 kWh at air temperature of 75˚C, vacuum pressure of 60 kPa and microwave power of 630W, respectively. Increase in inlet air temperature demonstrated an exponential decrease in energy consumption. It was also observed that increase of inlet air temperature, vacuum pressure and microwave power decreased specific energy consumption. Maximum and minimum values of shrinkage were 14.14% at air temperature of 75˚C, vacuum pressure of 60 kPa and microwave power of 630W and 7.78% computed at air temperature of 45˚C, vacuum pressure of 20 kPa and microwave power of 270W, respectively. The results indicated that the shrinkage increased with increasing air temperature, vacuum pressure and microwave power but the effect of air temperature was more than other parameters. Raising the drying temperature increased the movement of water molecules and made increasing the distance between the molecules in the structure of the sample. The highest and lowest values of total color change were 8.85 at air temperature of 75˚C, vacuum pressure of 60 kPa and microwave power of 630W and 2.61 at air temperature of 45˚C, vacuum pressure of 20 kPa and microwave power of 270W, respectively. Results showed that total color change increased with increasing air temperature, microwave and vacuum pressure. Conclusion With respect to the quality indices of shrinkage and color changes, the recommendation is to dry the almond kernels under air temperature of 45 °C, microwave power of 270 W and vacuum pressure of 20 kPa.
Volume 42 - Issue 2
Post Harvesting Technology
Poya kohansal makvandy; Majid Rahnama; Rasol Memar dastjerdy; Alireza Shafeinia
Abstract
Introduction Material conveying in the industries is carried out in the different ways. Pneumatic conveyors are widely used in industries. The special benefits of these conveyors have led them in the short term to widely used in different industries. Transfer of materials without dust dispersion, the ...
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Introduction Material conveying in the industries is carried out in the different ways. Pneumatic conveyors are widely used in industries. The special benefits of these conveyors have led them in the short term to widely used in different industries. Transfer of materials without dust dispersion, the flexibility to choose the vertical, horizontal or diagonal tubing, low maintenance costs and manpower, adequate safety and reliability during conveying at the high amounts of materials, easy and automatic control are the some benefits of the pneumatic conveying systems Materials and Methods The mean aperture and the coefficient of variation of sugar particles were determined by sugar crystal size distribution test. It is done based on the cumulative percentages of remaining sugar content on the sieve. The mean aperture (MA) and the coefficient of variation (CV) are obtained from the chart. 7 sieves are used for testing. The percentage of remaining sugar on each sieve was calculated. The amounts of D50% and D16% were calculated following the plotting the size of the sieves versus the cumulative percentage of the remaining sugar on each sieve graph. The conveying pressure drop includes the total pressure drop required for air alone (ΔPL), the material acceleration pressure drop (ΔPA), the friction and material collision pressure drop (ΔP*z), the pressure drop due to lifting and suspension of materials (ΔPG), and bends' pressure drop (ΔPB) in Pascal. Following determination of required power (293.42 w) to run the system, with a confidence coefficient of 3, a blower with a rated power of 700 w was selected. The amount of pressure produced by the selected centrifuge fan was measured by a pitot tube embedded in the blower outlet. The outlet air velocity was measured by a pressure gauge according to the principles of the pitot tube. Results and Discussion The treatments and their levels consisted of pipe lengths at three levels (2, 4 and 6 m), inlet air velocity at five levels (13, 16, 19, 22 and 25 m/s) and mass flow rate of sugar at three levels (160, 180 and 200 kg/h). The statistical analysis was done as a factorial based on a completely randomized design. Analysis of variance and comparison of means were done using Duncan's test at 5% level in each case. Then, the effects of the factors on pressure drop, mean aperture and coefficient of variation of particle size were investigated. Analysis of variance of data shows that the effect of conveying length, mass flow rate of sugar particles and inlet air velocity as well as their interactions and the interaction of three factors on air and sugar pressure drop is significant at 1%. In all conveying lengths, an increase in air velocity and consequently increased sugar particles' velocity at each mass flow rate causes an increase in frictional pressure drop due to the particle's collision with the wall as well as air collision with the pipe wall at each length and the sugar mass flow rate level. Also, total pressure drop has increased with mass flow rate at any velocity. Analysis of variance of data shows that the effect of conveying length, mass flow rate of sugar particles, inlet air velocity, and the interaction of mass flow rate and air velocity on qualitative properties of sugar is significant at 1% level. Considering the significance of the effects of the main factors and interactions between air velocity and mass flow rate, the effect of every main factors and the interaction of air velocity and mass flow rate on qualitative characteristics of the sample was investigated. With increasing velocity in each mass flow rate, the mean aperture and coefficient of variation significantly decreased and increased, respectively. Also, with increasing mass flow at any velocity, the mean aperture decreased and the coefficient of variation increased. By increasing the mass flow rate, the effect of the air velocity on the mean aperture reduction and increase in coefficient of variation increases, and at higher velocities, the mass flow rate effect is more pronounced. Conclusion The length of the pipe with a reduction by 15% in mean aperture and an increase of 137.5% in coefficient of variations than the initial sugar sample had the least effect on these two qualitative properties of sugar. With an increase in air velocity from 13 to 25 m/s, MA and CV values decreased by 20.27 and increased by 17.22, respectively. The velocity of 13 m/s with a reduction of 5.19% in the mean aperture and an increase of 6.69% in coefficient of variation compared to the initial sugar sample had the least effect on the size and the particle coefficient of variation size of the particles among all 5 velocity treatments. With the increase in particle mass flow rate of 160 to 200 kg/h, MA and CV values decrease by 16.49% and increase by 14.75%, respectively. The particle density increases with the mass flow rate.
Volume 44 - Issue 1
ُSaeid Hojati
Abstract
Introduction Khuzestan province in southwestern Iran is one of the most critical areas affected by dust storms due to the arid climate and the abundance of desert areas in its western and southern parts. Dust storms in these areas are among the most critical environmental issues. Air pollution, the development ...
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Introduction Khuzestan province in southwestern Iran is one of the most critical areas affected by dust storms due to the arid climate and the abundance of desert areas in its western and southern parts. Dust storms in these areas are among the most critical environmental issues. Air pollution, the development or increase of respiratory diseases, reduced soil fertility, damage to crops, and reduced solar radiation are among the most critical consequences of dust storms. Dust particles can absorb significant amounts of heavy metals, which facilitate their transport on a large scale due to their fine particle size distribution. Street dust is considered the major source of pollutants from a wide range of traffic, industrial emissions, pesticides, and mining activities. Although many studies have been conducted to identify the origin and pollution status of dust particles in the country, the assessment of pollution and source of street dust particles during dust storms, especially in Ahvaz city, has received less attention. .Thus, this study was conducted to: (1) identify the source of street dust in Ahvaz city, and (2): determine the level of contamination to Pb, Zn, and Cu.Materials and Methods Dust and soil samples were collected respectively at 69 and 23 points from streets and the surface soil (0-5 cm) in Ahvaz city in February 2015. To determine the particle size distribution pattern in the dust samples, they were first dispersed in 1 M sodium hydroxide and 10% sodium hexaphosphate solutions for 2 hours. Then, they were analyzed using A Malvern Hydro 2000g laser diffraction device. The ionic compositions of the dust and soil samples were also determined after extraction from 1 (dust/soil): 5 (water) suspension with an advanced Meterohm 861 model ion chromatography apparatus. The heavy metal contents of soil and dust particles were determined using inductively coupled plasma (ICP) spectroscopy. To determine the Pb, Fe, Cu, and Zn contents, 0.5 g of the dust or soil samples were digested with 60% nitric acid, and after 24 hours, the samples were heated for 0.5 hours at a temperature of 80 ° C. Then, they were filtered with Whatman 42 paper and finally were examined using an Agilent 7000 inductively coupled plasma (ICP) spectrometer. To assess the degree of street dust pollution in Ahvaz city, various indicators, including the single element pollution index and Nemerow integrated pollution index, were calculated. A pollution index is expressed as the ratio of the concentration of an element in soil or dust samples to the same component's baseline value in soil or dust sample. If this index is greater than 1, it indicates different levels of pollution.Results and Discussion The particle size distribution in the studied samples showed a bimodal pattern with more abundance of particles in the size of silt and fine sand. Accordingly, 57 to 89% of the particles were in the silt size, and 5 to 16% were in the size of fine sand. The results also indicated that the abundance of sodium, calcium, chloride, and sulfate ions was comparably higher than the local soils. Similarly, the average concentration of each heavy metal was higher than those of the local soils and the upper earth crust, which followed the order Zn> Cu> Pb. Accordingly, The average Pb, Cu, and Zn concentrations were 5.23, 6.37, and 6.89 times more than their corresponding values in the earth's upper crust. Accordingly, and based on the values obtained from the pollution index (PI), all the studied elements in the street dust of Ahvaz city could be categorized as highly polluted. The average of Nemrow integrated pollution index was found 7.26, which shows a high pollution level for street dust in Ahvaz cityConclusion It seems that dust particles collected from streets and sidewalks of the Ahvaz city are mainly originated from regional focal points in eastern and southeastern parts of the city. When Pb, Cu, and Zn concentrations in the street dust of Ahvaz city and those reported from different cities in Iran and other countries are compared, it is concluded that dust particles deposited over the streets and sidewalks in Ahvaz county have a higher degree of pollution. Therefore, Prompt actions are needed to lower the risk of these elements for the environment.
Volume 46 - Issue 1
Plant Nutrition, Soil Fertility and Fertilizers
Nasrin Teimoori; Mokhtar Ghobadi; Danial Kahrizi
Abstract
Introduction: Salinity stress reduces the yield of agricultural products. Water or soil salinity is caused by the increase in the concentration of soluble salts and minerals in water and soil, which leads to the accumulation of salt in the root area, to the extent that it prevents water absorption and ...
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Introduction: Salinity stress reduces the yield of agricultural products. Water or soil salinity is caused by the increase in the concentration of soluble salts and minerals in water and soil, which leads to the accumulation of salt in the root area, to the extent that it prevents water absorption and optimal plant growth. In general, tolerance to salinity is important during all stages of plant growth. Seed germination is the first stage of plant growth. Salinity stress reduces the percentage and rate of seed germination and also seedling growth. Crop yield is quantitatively and qualitatively dependent on the percentage, rate and uniformity of seed germination and also seedling growth. In recent years, a lot of attention has been paid to silicon due to its effect in reducing plant damage against some environmental stresses (such as drought, heat, heavy metals, salinity etc.). The studies show that silicon protects the plant against environmental stresses by stimulating growth and increasing the antioxidant enzymes activity. It has also been reported that the silicon is effective in increasing the chlorophyll content, stomatal conductance, photosynthesis rate and the resistance of plants under stressful conditions. Silicon increases the plant tolerance to the salinity by improving photosynthetic activity, increasing the relative selection of K+/Na+, increasing the soluble substances in the xylem, reducing sodium absorption, and mechanical protection against the toxicity of elements. Therefore, a research was carried out with the aim of investigating the effect of the silicon in increasing tolerance to salinity stress in camellia seedlings.Materials and Methods: A laboratory experiment was carried out in 2021 at Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran. The experiment laid out as a factorial based on a completely randomized design with three replications. The factors were camelina genotypes (Sohail cultivar and Line-84), salinity (four levels 0, -3, -6 and -9 bar) and silicon (five levels of 0, 2, 4, 6 and 8 mM). Salinity stress levels were prepared by different amounts of sodium chloride (NaCl) salt. Silicon factor levels were also prepared by different concentrations of sodium silicate (Na2SiO3). The experiment consisted of 120 petri dishes. Data analysis was done with MSTATC and SAS statistical softwares. Means were compared using Duncan's multiple range test (P≤0.05). Excel software was used to draw figures.Results and Discussion: The results showed that with the increase in salinity intensity, the growth characteristics and the amount of soluble proteins of camellia seedlings decreased, but the activity of catalase, peroxidase and superoxide dismutase enzymes and the amount of malondialdehyde increased. The lowest activity of catalase was observed under non-salinity conditions (control). But the highest activity of catalase enzyme (104.4 µM/min. mg protein) belonged to the treatment of -9 bar salinity. The use of silicon increased the seedling growth, the amount of soluble proteins, the activity of antioxidant enzymes, and the amount of malondialdehyde in camelina seedlings. The highest germination rate (23.97 seeds/day) was obtained in the treatment of 8 mM silicon. With the increase in silicon concentration, the amount of soluble proteins increased, so that in the 2, 4, 6 and 8 mM treatments, compared to the control treatment, the amount of soluble protein increased by 4, 8, 10.75 and 10.9%, respectively. By increasing the concentration of silicon, the activity rate of catalase enzyme increased. The highest activity rate of peroxidase enzyme (35.38 µM/min. mg protein) was observed in 8 mM silicon, which was significantly different from other treatments. The lowest activity of peroxidase was related to the control treatment. Line-84 had 8.65% higher activity rate of superoxide dismutase than the Sohail cultivar. With increasing salinity stress and silicon concentration, the activity rate of superoxide dismutase increased. On average, in the treatments of 2, 4, 6 and 8 mM silicon, the activity rate of superoxide dismutase was increased 11, 27, 44 and 57%, respectively, compared to the control (without silicon). The highest amount of malondialdehyde (44.42 µM/g fresh weight) was observed in the treatment of 8 mM silicon.Conclusion: The results of this experiment showed that the application of silicon, by increasing the activity of antioxidant enzymes, reduced the oxidative damage caused by reactive oxygen species and thus protected camellia seedlings against salt stress. In general, it seems that the use of silicon has been effective in reducing the adverse effects of salinity stress on growth and biochemical characteristics of camelina seedlings.
Volume 41 - Issue 2
Soil Physics, Erosion and Conservation
Hossein Kheirabadi; Vahidreza Jalali; Hormozd Naghavi
Abstract
Introduction: The trap efficiency of sediment catcher plays an important role in the study of wind erosion and its measurements. The sediment trap efficiency generally varies with particle size distribution and wind velocity. Worldwide, wind tunnel facility has been used by many researchers to determine ...
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Introduction: The trap efficiency of sediment catcher plays an important role in the study of wind erosion and its measurements. The sediment trap efficiency generally varies with particle size distribution and wind velocity. Worldwide, wind tunnel facility has been used by many researchers to determine the efficiency of sediment samplers designed for the measurement of the deposition of Aeolian dust. Therefore, this study was conducted to investigate the efficiency of BSNE sampler, the transportability of sediment particles per wind velocity, using wind tunnel facility under laboratory conditions. In addition, a new parameter by which sediment transportability can be quantified was introduced. Materials and Methods: The wind tunnel experiments were carried out in an open circulation wind tunnel at the Soil Erosion and Conservation Laboratory, Shahid Bahonar University of Kerman, Iran. The wind tunnel consists of three sections including 1) wind generator section for producing different wind velocities, 2) test area section in which soil sample is placed and 3) sediment collector section. The wind tunnel has a uniform cross section with width and height of 80 cm by 80 cm and a total length of 12 m, with a working section of 7 m in length. The wind velocity can be varied continuously from 1 to 30 m s-1 at 40 cm height equal to 175 km/h at 10 m height. The soil used for the experiments is taken from the surface layer (0-20 cm depth) of a cultivated land from Kerman province (30 14 N and 57 06 E). The soil sample at first was air-dried, thoroughly mixed and then crushed to pass separately through 2, 4.75 and 8 mm sieve sizes in order to prepare three subsamples with different max size of 2 (D2mm), 4.75 (D4.75mm), 8 (D8mm) mm. Experiments were done as factorial based on completely random design with three replications. The factors were the height of sampler, wind velocity and soil aggregate size. Three wind velocities of 6, 10, 14 m s-1 at 40 cm height were introduced over the leveled soil surface with 7 m length and the sediment was collected using BSNE sampler at different heights of 10, 30, 50 and 70 cm at the outlet of the wind tunnel. Also, the total mass of soil loss was measured by differential weighing method for each erosion event. Results and Discussion: Results showed that the sediment flux decreased with increasing height at different wind velocities and was quantified using an exponential function, satisfactorily. The sediment transport rate near soil surface for soils D2mm, D4.75mm and D8mm ranged from 0.28 to 2.11, 0.19 to 1.06 and 0.23 to 0.65 g cm-2 min-1, respectively. This implies the soil having coarser aggregates exhibits less erodibility. Moreover, sediment flux at all heights was increased with increasing wind velocity, whereas it was reduced as soil surface roughness increased. In general, the efficiencies of the BSNE samplers varied from 53.2% to 82.1%, depending on soil aggregate size and wind velocity. The efficiency of BSNE obtained for D2mm, D4.75mm and D8mm, at wind velocity of 6 m s-1 was 61.4, 53.2 and 77.5%, at wind velocity of 10 m s-1 was 56.5, 78.7, 69.5% and at wind velocity of 14 m s-1 was 62.4, 79.1, 82.1%, respectively. Also, the results indicated that the transportability of sediment particles per wind velocity decreased with height, which was described through an exponential function. Overall, the particles in the size range of 125 to 500 micron exhibited the maximum selectivity and frequency in the sediments collected at 10 and 30 cm heights. The finding of this study revealed the high importance of vertical distribution of sediment size particles and their selectivity in wind erosion studies. Conclusion: The finding of this study indicated that most sediment particles were transported near the soil surface, this means that by appropriate conservation practices such as making sufficient roughness through this height, wind erosion can be reduced, significantly. Also, it was found the soils containing coarser aggregates due to higher random roughness show less erodibility and wind erosion rates. Finally, the efficiency of sediment sampler was found to be affected by some other factors, therefore, more attention is needed in the application of these types of samplers while the calibration is of importance, as well.
Volume 45 - Issue 2
Mehdi Naderi Khorasgani; Ghasem Haj Hassani; Jahangard Mohammadi; Ahmad Karimi
Abstract
The Effect of Different Tillage Instruments on Some Soil Physical Characteristics and Soil TranslocationIntroductionTillage is defined as disturbing the soil and changing soil physical condition of seedbed and root zone and making it suitable for cultivation. Soil physical characteristics like soil moisture ...
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The Effect of Different Tillage Instruments on Some Soil Physical Characteristics and Soil TranslocationIntroductionTillage is defined as disturbing the soil and changing soil physical condition of seedbed and root zone and making it suitable for cultivation. Soil physical characteristics like soil moisture and temperature conduction, bulk density, porosity and particle size are changed in the following of soil tillage. Tillage also increases water infiltration rate and plays an important role in soil moisture protection and decreasing flood hazards in arid and semi-arid regions. Molboard plough is currently implemented for tillage in different parts of Iran including Chaharmahal va Bakhtiari province. There are evidences which show Moldboard plough triggers physical soil characteristics deterioration and soil tillage erosion. Tillage translocation coefficient, as a component of tillage erosion, is defined as the amount of soil transition for 1 m width of tillage instrument. Comparing the impacts of available tillage instruments on physical soil characteristics, soil transition and their efficiency with of Moldboard plough may encourage field managers to substitute other instruments with Moldboard plough. This research aimed to: 1) study the impacts of the currently available tillage instruments (Moldboard, Disk and Chisel plough) on some prominent physical soil characteristics and 2) compare soil translocation coefficients of the mentioned tillage instruments. Materials and Methods This research was executed in Research-Training Field of Shahrekord University, Shahrekord county, Chaharmahal va Bakhtiari Province, Iran. A split plot experimental design with complete randomize block was considered with 3 major treatments of tillage instruments (Molboard, Disk and Chisel plough), minor treatments of slope (0, 3, 6 and 8%) and tillage speeds (2, 5, and 8 km h-1) and 3 replications. The conventional tillage depth of 25 cm was adjusted for all three tillage instruments. Standard protocols were applied and soil electrical conductivity (EC), pH, calcium carbonate equivalent (CCE), organic matter and soil texture components were measured before tillage application and soil field capacity (FC), mean weight diameter (MWD) of aggregates, geometric mean diameter (GMD) of aggregates, aeration porosity (Fa), bulk density (ρb) and water stable aggregates (WSA) were measured using standard protocols after tillage implementations. Colored gypsum cylinders were used as indicators for detecting soil translocation. The transition distance of the colored gypsum cylinders of each layer of tillage depth (0-9, 9-18 and 18-25 cm) was measured using tape meter or ruler and mean transition for each layer were calculated. In the next step the depth weight soil translocation was calculated for each tillage instrument. Results and Discussions Chemical analysis of soil samples showed that soils were non-saline, soil OM content was less than 1% and CCE of soil samples was relatively high. Physical soil analysis of soil samples before tillage implementation indicated that there was not any restriction for plant root development and aeration as ρb was relatively low and aeration porosity was 10% <, respectively. Analysis of variance (ANOVA) indicated that the effects of tillage type on MWD and ρb were significant (P < 0.05). Comparing the means of MWD and ρb induced by tillage instruments (Duncan method) revealed significantly higher values of MWD and lower values of ρb for soils which were treated by MB plough, the results were corresponded to the finding of other researchers. There were not significant differences between MWD and ρb of soils which were treated by disk and chisel plough. The results also showed that tillage instruments did not impact on physical characteristics like FC, WSA, GMD and FA. Non-significant impact of MB plough on soil moisture condition also was reported by other researchers in the northwest of Iran. The ANOVA was calculated for soil translocation and showed that the effects of tillage instruments were significant (P < 0.05) for all three layers of soil depth. Mean soil translocation of surficial layer of tillage depth (0-9 cm) was significantly higher than of other layers of tillage depth. Despite other researchers' findings, our research indicated that the slope levels were not significant for soil translocation. This research also revealed that tillage speed significantly (P < 0.05) impacted on soil translocation which was corresponded to findings of other researches in different parts of the world. Interaction of slope-speed and tillage type-speed were significant (P < 0.05) which could be due to accelerated impacts of speed on soil translocation in steep areas. Amount of coefficient of translocation for MB plough was 141 kg m-1 per application. This value was about one third of soil translocation which was reported by others from Belgium (545 kg m-1 y-1) or Denmark (456 kg m-1 y-1) and very closed to the finding of Spanish researchers (164 kg m-1 per application). The coefficient of translocation for disk and chisel plough were 114 and 93 kg m-1 per application, respectively. According to researchers from Portugal, the coefficients of translocation for disk and chisel plough were in ranges of 0-333 kg m-1 and 18-770 kg m-1 per application, respectively. The magnitude of soil translocation coefficients for tillage instruments were in order of MB plough > disk plough > chisel plough. Keywords: Aggregate mean weight diameter, Bulk density, Soil coefficient of translocation
Volume 46 - Issue 2
Soil Genesis and Classification
Vahideh Sadeghizadeh; seyed ali abtahi; Majid Baghernejad; Azam Jafari; Seyed Ali Akbar Moosavi
Abstract
Introduction The number of environmental variables used in digital soil mapping has increased rapidly, which has made it a challenge to select and focus on the most important covariates. No environmental covariates have the same predictability in modeling, and some covariates may introduce noise that ...
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Introduction The number of environmental variables used in digital soil mapping has increased rapidly, which has made it a challenge to select and focus on the most important covariates. No environmental covariates have the same predictability in modeling, and some covariates may introduce noise that reduces the predictive power of the models used. On the other hand, it is beneficial to identify all environmental variables to obtain spatial information that can improve predictions. In this regard, the feature selection algorithms help reduce the dimensions of the predictive model by identifying the associated covariates. Therefore, this study aims to investigate different feature selection algorithms in the selection of auxiliary variables and evaluation their effect on the predictive model. Materials and Methods The area under study is a part of Darab city in the southeast of Fars province with an area of about 31000 hectares. In the study area 140 profiles were determined and excavated according to the diversity of geomorphological units and thus the type of soils. After excavating the profiles and checking the morphological characteristics of each soil profile, a sufficient amount of soil samples were collected from the genetic horizons and transported to the laboratory for further analysis. Some of the physical and chemical parameters of soils were tested using accepted techniques after air drying and passing through a 2 mm sieve. Finally, all profiles up to the great group level were classified using the U.S. Soil Taxonomy based on the data collected from field observations and the outcomes of laboratory analysis. Environmental variables include the parameters derived from the Digital Elevation Model, Landsat 8 images, geology and geomorphology maps of the study area. All parameters were derived using ArcGIS, SAGAGIS and ENVI softwares. In the present study, four different feature selection techniques including Variance Inflation Factor (VIF), Principal Component Analysis (PCA), Boruta and Recursive Feature Elimination (RFE), were used to identify an optimal set of covariates for predicting spatial classification of soil classes at the great group level. In addition, a Random Forest model (RF) with 10-fold cross-validation and the 5-repeat method, was used to compare different feature selection strategies in soil class mapping. The comparison of different feature selection techniques in estimating soil classes, was based on the evaluation criteria of accuracy and Kappa coefficient between observed and predicted values.Results and Discussion The results showed that the prediction accuracy increased by using variables selected with different feature selection methods compared to using all variables in the model. In addition, the improvement in predictive performance is different between the four types of feature selection. The VIF and PCA methods had the highest and lowest accuracy index and Kappa coefficient, respectively. The Boruta method, with the lowest number of variables, improved the model's performance after the VIF method. However, the Kappa coefficient showed poor agreement between predicted and observed values for all approaches. The imbalance of soil classes could be a reason for decreasing the accuracy index and Kappa coefficient. However, the random forest model, with and without feature selection methods, identified all soil great groups in the study area. Therefore, it can be concluded that the Random Forest algorithm is a very powerful technique for spatial prediction of soil classes in the study area. Although the performance of the model varied using different feature selection algorithms, the predicted soil maps had similar spatial patterns. Based on the prediction of model with the variables selected by the VIF, the resulting map indicates that Ustorthents soils are mainly located in high altitude regions with steep slopes. Haplustepts, Calciustepts, and Calciusterts great groups have developed in places with low to medium slopes. Haplosalids have developed downstream of the salt dome. Great groups of Ustifluvents were discovered in fluvial sedimentary plains. Endoaquepts were found in the floodplains, which had the smallest area on the predicted map. Conclusion Overall, the findings indicate that the feature selection methods can utilize significant dependencies among relevant covariates to predict soil classes and to improve modeling accuracy. In the current study, the environmental factors, obtained from the Digital Elevation Model, were selected as key variables, showing the importance of topography and morphology in the classification of soil types in the area. Although the selected variables improved the performance of the model, the prediction of soil classes was random. This could be attributed to the imbalance of soil classes.
Volume 44 - Issue 2
Mansoreh Bameri; Farhad khormali; Hossein kheirabadi
Abstract
Introduction. Soil is an essential part of the environment. It is important for the production of food and other crops. Soil erosion and sedimentation are complicated and least well-known environmental problems worldwide (Mahmoodabadi et al, 2014). Recently, the application of compounds that modify and ...
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Introduction. Soil is an essential part of the environment. It is important for the production of food and other crops. Soil erosion and sedimentation are complicated and least well-known environmental problems worldwide (Mahmoodabadi et al, 2014). Recently, the application of compounds that modify and improve soil quality and also reduce soil erodibility has been more thoroughly researched. These compounds are known by the common name of soil amendments with a relatively high variety such as gypsum, basanite, zeolite, chemical amendments, organic additives, a variety of chemical, biological and composite polymers, soiltac, fungi, polyvinyl acetate, vermicompost and cattle manure, biochar, straw mulching and cyanobacteria and bacteria (Behzadfar et al, 2017). The objective of this study was to investigate the influence of bentonite clay and slope gradient on runoff and sediment concentration and some hydraulic Characteristics in the Loess soil using a rainfall simulator. Materials and Methods The experiments were conducted using a rainfall simulator at the Soil Erosion and Conservation Laboratory, Gorgan University of Agricultural Sciences and Natural Resources, Iran. The soil used for the experiments is taken from the surface layer (0-30 cm depth) of loess lands from Golestan province (37° 55ʹ N and 55° 29ʹ E). The soil sample at first was air-dried, thoroughly mixed and then crushed to pass through 10 mm sieve size. Experiments were done as factorial based on completely random design with three replications. The factors were the bentonite clay at four level (0, 2, 5 and 10 % weight) and slope steepness at three level (10, 20 and 30%). In all experiments, each soil sample was put in the flume, then was saturated from the bottom for 24 h. Afterwards, the drainage water was removed out of the tray, and the experiment lasted for 45 min. For each rainfall event, the sediment-laden overland flow was sampled at selected time intervals and volumetrically measured. The sediment-laden overland flow was sampled at several time intervals and the sediment concentration was determined . The sediment in the collected samples was allowed to settle, separated from the water, and dried in an oven at 105 °C for 24 h. The sediment concentration was determined as the ratio of dry sediment mass to sampled runoff volume for each time interval.Different hydraulic parameters including flow depth, shear stress, stream power, and unit stream power were measured.Results and Discussion The result showed that the sediment concentration decreased with increasing levels bentonite at all slopes. At 10 % slope steepness, the mean sediment concentration varied 32.48 in the control treatment to 24.67 kg m-3 at level 3 bentonite treatment. At 30% slope the corresponding value were 474.52 and 224.14 kg m-3. Therefore, with increasing slope steepness the sediment concentration increased. Totally, the use of bentonite at level 10 % weight could decrease 46% of sediment concentration in comparison with control treatment. Defersha and Melesse (2012) found that rain intensity and slope gradient had significant influences on sediment concentration. Slope gradient is important as more soil particles are splashed down-slope than up-slope (Dunne et al. 2010; Grismer 2012). According to Fig. 2, the obtained flow depth was 1.92×10−4, 1.92×10−4, 1.92×10−4 and 1.92×10−4 m for 0, 2, 5, 10% clay treatment, respectively. Also, the depth flow ranged from 3.6×10− 4 to 1.96×10−4 m on 10 to 30 % slopes. Totally, the depth of flow decreased with increasing slope steepness for all treatments. In fact, due to higher flow velocities at steeper slopes, shallower flow depths were achieved. Statistical analysis (Table 2) confirmed a significant positive main effects of application levels of bentonite and slope on shear stress, power flow and unit power flow. The clay treatment showed significant reductions ranging from 2 to 50% compared to the control treatment for all slopes. Unit stream power varied from 0.0084 to 0.0095 ms-1, 0.0176 to 0.0241 ms-1 and 0.030 to 0.057 ms-1 for 10, 20 and 30 % slope, respectively. Totally, with increasing slope steepness, all the hydraulic parameters, except flow depth, increased. While with increasing percentage of bentonite clay, shear stress and depth flow and stream power, decreased. Consequently, the maximum values were observed at the steepest slope (30 %) and control treatment (0%). Conclusion Based on the results obtained during the present study, it can be concluded that the bentonite can be considered as an effective modifier of soil physicochemical properties leading to better performance in soil and water conservation in loess lands. Keywords: Bentonite, Simulator Rain, Slope, Sediment Concentration, Hydraulic Characteristics
Volume 43 - Issue 2
Mohammad Zeinvand; Afsaneh Alinejadian; Mohammad Feizian; Omidali َAkbarpour
Abstract
IntroductionDue to the use of fossil fuels, land use changes, and deforestation, it increases atmospheric carbon dioxide, which affects greenhouse gas emissions, results in global warming, effectively. Since crop production directly depends on climate, agriculture is one of the first sectors affected ...
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IntroductionDue to the use of fossil fuels, land use changes, and deforestation, it increases atmospheric carbon dioxide, which affects greenhouse gas emissions, results in global warming, effectively. Since crop production directly depends on climate, agriculture is one of the first sectors affected by climate change. Increasing greenhouse gas emissions leads to warming up and warming has devastating effects on organisms life, damaging natural ecosystems, causing floods, droughts, and disrupting the climate and ecological balance. Total soil organic carbon is the ability of trees and other plants to absorb carbon dioxide from theatmosphere and store it as carbon in wood, roots, leaves, and soil.Total soil organic carbon of plant biomass and Total soil organic carbon under this biomass is the simplest and most economically feasible solution to reduce atmospheric CO2. In this regard, an experiment was carried to investigate the effect of three amendment materials (alfalfa residues, straw and wheat straw, and poultry manure) on some soil characteristics, soil and wheat organ Total soil organic carbon potential. Materials and MethodsTo investigate the possibility ofimproving soil carbon sequestration, carbon content of plant and soil and some soil characteristics, an experiment was design in a randomized complete block design (RCBD) in the crop year 2018-2019, in a farm in Dasht-e Aramou, Dare Shahr-Ilam province, in three replications on the wheat plant. Trial factors include two factors, the types and amount of amendment materials (alfalfa residues at 5, 10 and 15 t/ha, straw and wheat straw at 5, 10 and 15 t/ha, poultry manure at three levels of 2, 4 and 6 t/ha and chemical fertilizer is 100 percent fertilizer requirement). The studied traits included root carbon, shoot carbon, root total organic carbon, and shoot total organic carbon, total organic carbon, soil organic carbon percentage, total soil organic carbon, soil nitrogen, soil phosphorus, soil potassium, soil pH and soil Electrical Conductivity (EC). Results and DiscussionThe use of amendment materials had a positive effect on most of the studied traits compared with the lack of application of amendment materials. The results showed that the amount of Total soil organic carbon and the percentage of carbon in shoots were higher than roots. The highest total organic carbon, percentage of carbon in plant and soil phosphorus were observed in 6 t/ha poultry manure (M6) while the highestTotal soil organic carbon and soil carbon content was obtained in 15 t/ha straw and wheat straw (G15). Also, the highest amount of soil nitrogen and potassium was obtained in 15 t/ha (Y15) alfalfa residues and the lowest amount in control treatment which were 47and 64 percent higher than the control, respectively. Contrary to all measured traits, pH and EC values were decreased by adding soil amendment materials. The highest was obtained in control treatment and lowest was observed in 15 t/ha (G15) straw and wheat straw which was 4.4 percent and 50.8 percent lower than the control, respectively. Conclusion Gradual degradation of organic matter increases the efficiency of nutrients, the effect of these compounds on the plant's yield and soil properties for several years. The use of high quality plant residues, if combined with optimized management, will have a good result, especially if the timing of the release of nutrients from decomposing plant debris coincides with the need for the crop. Under such conditions, the time gap between the release of elements from plant residues and absorption of elements by the plant will be reduced and by reducing nutrition elements, it will increase absorption efficiency. In general, the effect of fertilizer type and plant residue on the amount of carbon of the plant and soil as well as the amount of nutrients in the soil was significant at 1% level. Among the different treatments, 6 ton/ha of poultry manure had the most effect on total soil organic carbon and carbon storage in plant organs, and treatment of 15 ton/ha wheat straw had the most effect on total soil organic carbon and carbon storage in soil. Alfalfa residue treatment had the most effect on soil phosphorus and potassium content and poultry manure had the most effect on soil nitrogen. Regarding to the lower price of plant residue, it is more appropriate than poultry. Due to availability of poultrymanure in the most parts of the country, it recommends more than other fertilizers.
Volume 44 - Issue 3
Fatemeh Hassani; Ataallah Khademalrasoul; Hosein Shekofteh
Abstract
IntroductionSoil is the upper layer of earth in which plants grow and is consequently very important for organisms and human nutrition. The protection of the soil against degrading processes, such as soil salinization and alkalization, is one of the main challenges in sustainable land management. Soil ...
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IntroductionSoil is the upper layer of earth in which plants grow and is consequently very important for organisms and human nutrition. The protection of the soil against degrading processes, such as soil salinization and alkalization, is one of the main challenges in sustainable land management. Soil salinization and alkalization are two major environmental concerns leading to soil degradation especially in arid and semi-arid regions across the world. The balance of organic carbon in the soil is important for soil sustainability. Intensive cultivation enhance soil organic carbon (SOC) depletion. In order to alleviate the detrimental effects of SOC depletion, carbon-rich organic amendments such as biochar or compost are often applied to the soil. Therefore application of organic amendments to soil is an effective strategy to improve soil properties and to mitigate the negative impacts of inappropriate management strategies. Biochar is a carbon-rich compound produced by the pyrolysis of biomass in oxygen-limited conditions. Its use as an organic amendment to soil with specific inherent characteristics has been recognized. In this regard recent studies have shown that application of biochar to soil as an organic amendment can improve soil physical properties and help to keep the carbon balance in the soil. Moreover, compost as an organic amendment is capable to improve soil properties and increase the soil productivity. Methods and MaterialsThe soil sampling was carried out near Kabutar Khan in Rafsanjan, Iran (56°22′N, 30°18′E), on a saline-sodic soil with Silty Clay soil texture (42% silt, 50% clay and 8% sand). The biochar was obtained from three different feedstocks consist of Conocarpus erectus, bagasse of Sugarcane and hard shell of Pistacia Vera. The obtained feedstocks were pyrolyzed at 400°C for 2 h with increasing rate of 7 °C/min in a sealed reactor to prevent O2 input (Muffle Furnace, SEF-101 Model). Afterwards the produced biochar was cooled slowly to the room temperature, then the EC, pH, specific surface area and CHNS of biochars were measured using the standard methods. The required amounts of soils and biochars were weighed by a total 5000 g dry weight of sample and mixed in the dry state. The soil samples were received three doses of biochar (0, 2, 4 % biochar, w/w). The mixtures of soil and biochar were packed into pots and controlled a bulk density of about 1.5 g cm-3 by artificial compaction. Treatments were replicated three times. The soil without any biochar was used as the control. The mixtures were wetted at three soil moisture contents (25, 50 and 75% field capacity) during incubation time (120 days). The treatments were kept at a temperature-controlled glasshouse. After 120 days of incubation, the untreated soils and biochar-amended soils were taken for physical and chemical analyses.Particle size distribution was measured by hydrometer method and soil organic carbon by oxidation method with potassium dichromate. The consistency limits (liquid limit and plastic limit) of soils were determined according to the ASTMD4318 procedure. The field capacity was measured using the pressure plates with the standard rings in the lab. Mechanical strength is a sensitive indicator of the soil physical condition and has been commonly used to evaluate soil water erosion, structural stability, tillage performance, and root penetration. Higher strength found in saline-sodic soil often impedes seedling emergence and root penetration. Results and discussionOur results revealed that application of organic matter in the form of biochars and compost was effective on soil aggregation. The formation and stability of the soil aggregates play an important role in the crop production and soil degradation prevention. Moreover, the biochar application showed two main effects including direct and indirect effects. Our results confirm the addition of biochar to soil can cause a substantial and significant change in the soil physical characteristics of the strongly acidic Ultisol, namely a significant increase in LL and PI, higher water-holding capacity, and reduction in mechanical strength. These changes are undoubtedly associated with the particular properties of biochar and in particular with its high porosity and low bulk density. The beneficial effect of biochars on soil physical properties is mainly due to the dilution effect of biochar with higher porosity and lower density. When the biomass is heated, volatile matters may release out of the biomass to create micropores on the surface, and meanwhile those trapped inside the biomass are evaporated to expand the microstructure. Thus, the resulting biochar has much higher surface area and porosity. These properties are particularly useful for soil application of biochar especially for enhancing soil water-holding capacity, reducing mechanical strength, and increasing soil aggregation. The dilution effect can be attributed to the increased volume of pores as well as the decreased particle density in soil amended with biochar. The effectiveness of different biochars in improving the soil physical properties can be explained by their porosity and bulk density.ConclusionOur results depicted that application of biochars and compost as an organic amendments improved mechanical quality of the saline and sodic studied soil. Indeed all organic treatments decreased bulk density and enhanced soil aggregate stability while the biochar of Conocarpus illustrated the greatest effectiveness on soil physical and mechanical properties. Therefore it is a possibility to apply this biochar to the soil in the field scale but regarding the accessibility of biochar of Pistachio skin in the study area therefor we have another alternative to utilize in the soil. This research was conducted in the small scale and in a short time. Therefore, it is suggested that supplementary studies are carry out on farm scale for a longer periods.
Volume 43 - Issue 3
Shamim Shirjandi; A Khademalrasoul; Adel Moradi Sabzkuhi; Hadi Amerikhah
Abstract
IntroductionSoil degradation is a phenomenon which destructs the soil structure and mitigates its capacity for production. Among several processes that cause soil degradation, soil erosion as one of the most common forms of soil degradation leads to loss of soil surface and including on-site and off-site ...
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IntroductionSoil degradation is a phenomenon which destructs the soil structure and mitigates its capacity for production. Among several processes that cause soil degradation, soil erosion as one of the most common forms of soil degradation leads to loss of soil surface and including on-site and off-site effects. Although soil erosion is a natural process on the earth, but destructive human activities such as burning agriculture residue, deforestation, overgrazing, and lack of proper soil conservation practices; accelerate the soil erosion and enhance the negative outcomes of erosion. Selecting and implementing of management scenarios requires assessment of soil losses from different management operations. Generally, management practices consist of structural and non-structural methods that used to reduce erosion, prevent nutrient removal, and increase soil infiltration capacity. Application of simulation models is an appropriate technique to evaluate erosional conditions. GeoWEPP is a process-based, distributed parameters and continuous simulation model of water erosion in watersheds with the possibility to simulate hillslopes and hydrographical network. Locating problems in real world usually face with a large amount of information and decision space that need to be optimized using evolutionary algorithms due to the variety of aims considered. Considering diversity of evolutionary algorithms, NSGA-II is one of the most common and a usable multiobjective evolutionary algorithm (MOEA) which is very powerful tool for solving problems with conflicting objectives. Development of simulation models along with optimization algorithms that are capable of analyzing very complex systems, have found to be very efficient in real world problems. Simulation-optimization models are powerful tools for solving problems for least cost and best performance.Methods and materialsTo predict sediment yield and runoff in the studied watershed, the GeoWEPP integrates WEPP model with TOPAZ (Topography Parameterization), CLIGEN (Climate Generation) and GIS tool (ArcGIS). The GeoWEPP model provides the processing of digital data including DEM ASCII file, soil ASCII file and landcover ASCII file. To generate climate file, the CLIGEN module which is a stochastic weather generation model was utilized. Furthermore in TOPAZ part the CSA (critical source area) and MSCL (minimum source channel length) to delineate streams and also the outlet point of studied watershed were defined using GeoWEPP linked to ArcGIS. Using the basic maps including DEM, slope, soil great groups and soil database the GeoWEPP model simulates and generates the hillslopes automatically; therefore this is an important advantage of GeoWEPP compared to WEPP model which is capable of performing the simulation of watershed components spontaneously. In this study in order to optimize the placement of Gabions, 118 channels and 5110 candidate sites for gabion construction were simulated and evaluated. For optimization process; regarding the number of objectives firstly the AHP technique was used to prioritize the effective factors on the placement of Gabions. Analytical hierarchy process is a structured technique for organizing and analyzing complicated decisions based on mathematical calculations. The AHP depicts the accurate approach for quantifying the weights of criteria and estimates the relative magnitudes of factors through pair-wise comparisons. The AHP technique includes creating hierarchical structure, prioritizing and calculating relative weights of the criteria, calculating the final weights and system results compatibility. The main criteria (objectives) for our study were minimum distance from road, minimum distance from residential area, maximum length of main channel, maximum sediment yield, maximum discharge volume and maximum volume structure. Indeed using the AHP technique it was possible to restrict the decision making space and the number of possible options, therefore simplify the optimization process. Then NSGA-II (Non-dominated Sorting Genetic Algorithm) was applied in order to find the best solutions, i.e. the Pareto front, of alternatives for optimal location of structures based on the two objectives with higher priority and distance constraint. Results and discussionThe results of paired comparison matrix and prioritizing showed that the length of main channel in the watershed is the main effective criterion in locating Gabion structures. The first priority is considered as the most critical channel which produces the highest sediment yield; therefore the most expensive structure is established on that channel. After channel length, the volume discharge was the second priority of effective factors for gabion placement. Using the results of AHP, based on channel length and discharge volume the non-dominated sorting genetic algorithm (NSGA-II) was performed and the priority of critical channels and the specific position was determined from 1 to 35 among 5110 candidate sites for Gabion construction. Using the ArcGIS, slope map and the lowest width of the critical channels the place for gabion construction as a point was determined. Moreover the main output of GeoWEPP is the spatial distribution of sediment yield and based on this map the sediment yield was classified in the watershed. Based on this map the red color was the highest amount of sediment yield (more than 4 ton) in the watershed. ConclusionResults confirmed that application of simulation-optimization techniques helps to select the best sites to construct the Gabion as structural best management practice therefore is a cost-effective technique.
Volume 45 - Issue 4
Seyedh Sanaz Mousavi; ُSaeid Hojati; Ahmad Landi
Abstract
Introduction Soils at the earth crust could be considered as the result of interaction among five soil-forming factors. The strength and weakness of each of these factors causes formation of different soils with different properties and horizons. Previous studies have reported that Iranian agricultural ...
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Introduction Soils at the earth crust could be considered as the result of interaction among five soil-forming factors. The strength and weakness of each of these factors causes formation of different soils with different properties and horizons. Previous studies have reported that Iranian agricultural soils show different levels of zinc deficiency. Although the literature review confirms many studies in this regard, the number of studies compared the distribution of the chemical forms of micronutrients and especially zinc after the application of chemical fertilizers in the soils of Khuzestan especially in the common diagnostic horizons of these soils, is limited. Therefore, the purposes of this study were two-fold: (1) to measure and determine the chemical forms of zinc in selected diagnostic horizons (Mollic, Calcic and Salic) of Khuzestan Province, (2) to identify the contribution of some physical and chemical properties of these soils on availability of zinc.Materials and Methods In order to carry out this research, Mollic and Calcic diagnostic horizons were collected from the Karun 3 watershed in the east of Khuzestan province, with thermic and mesic temperature and xeric moisture regimes. However, Salic diagnostic horizon was sampled from the route between Ahvaz to Abadan in the southwest of the province, with hyperthermic temperature regime and an aridic moisture regime. After being transferred to the laboratory, the samples were first air-dried, and after passing through a 2-mm sieve and before carrying out the fractionation and speciation experiments, their physical and chemical characteristics including electrical conductivity (EC), pH, particle size distribution, organic C content, calcium carbonate equivalent, cation exchange capacity (CEC), specific surface area (SSA), and total and DTPA extractable Zn were determined employing common standard procedures (Table 2). Different forms of zinc in the solid phase of the Mollic, Calcic, and Salic soils were extracted using the method described by Tessier et al. (1979). In brief, 5 components including water soluble, exchangeable, carbonates, iron and manganese oxide, organic and residual forms were determined. The concentration of zinc in the extracts obtained from different stages of successive soil extraction was determined using an atomic absorption device. In order to estimate the accuracy of the extraction method described above, the recovery percentage was calculated. To do this, one gram of a certified soil from the state of Montana (ANIST 2711A) was used and the recovery percentage of zinc in our study was 94.5%. In order to determine the chemical forms of zinc in the solution phase of the soils, 100 g of each soil sample was saturated with double distilled water, and then extracted using a vacuum pump and Buchner funnel. The extracts were passed through filter paper and centrifuged at 2500 rpm for 8 minutes, then the values of pH, electrical conductivity, dissolved organic carbon, and dissolved cations and were determined using common laboratory methods described earlier (Table 1). These parameters were considered as input in Visual MINTEQ software to predict zinc species in soil solution (all free and complexed organic and mineral species). The data analysis was conducted considering a factorial design based on a completely randomized design through SAS software (v9.1). The comparison of means was also done using the Tukey’s test at the 5% probability level. Graphs were also drawn using Origin software (v2018).Results and Discussion Considering the critical level of zinc deficiency in the soil (1 mg/kg), all the soils are deficient in terms of available zinc. The studied soils are among alkaline and calcareous soils, but they did not show any differences from each other in terms of soil texture. It is noteworthy that the mollic horizon has a greater cation exchange capacity and specific surface area than the other two soils due to the higher amount of organic matter and the greater abundance of clay contents. The results of zinc fractionation in the studied soils showed that organic, carbonate and oxide forms in the Mollic and Calcic horizons, and carbonate, oxide and exchangable forms in the Salic horizon were the dominant forms of Zn which affects its supply to the plants. The results also showed that Zn2+, Zn(OH)2(aq), Zn-DOM (aq), and Zn (OH)+ species were the dominant species of Zn in soil solution of all diagnostic horizons. The result of Zn mobility factor calculations with the addition of 10 mg/kg Zn(SO4)2 showed lower values of mobility factor in the mollic diagnostic horizon than those of the calcic and salic.
Volume 44 - Issue 4
Ali Reza JAfarnejadi; Fatemeh Meskini-Vishkaee; Mohammad Hadi Mousavi Fazl; Gh. Lotfali Ayeneh; Leila Behbahani
Abstract
abstractIntroduction In Iran, salinity is a pervasive and limiting Factor of agricultural sustainable production. Plants in saline conditions are exposed to limited absorption of nutrients, water and toxicity of some elements and subsequently, their yield will be affected by salinity. Moreover, being ...
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abstractIntroduction In Iran, salinity is a pervasive and limiting Factor of agricultural sustainable production. Plants in saline conditions are exposed to limited absorption of nutrients, water and toxicity of some elements and subsequently, their yield will be affected by salinity. Moreover, being calcareous, the salinity of soil and irrigation water, low organic matter in the country's arable soils, and excessive consumption of phosphate fertilizers cause a lack of available nutrients for the plant uptake. As regards more than three billion people in the world suffer from a lack of micro nutrients, the bio-enrichment in strategic products such as wheat is necessary.Materials and Methods This study was carried out in Khuzestan province in a calcareous and saline soil with silty clay texture under wheat cultivation as a factorial experiment in a randomized complete blocks design with three replications. Factors included four levels of zinc (zero, 30, 60 and 120 kilograms per hectare of zinc sulfate) and the four levels of iron (zero, 2.5, 5, 7.5 kilograms per hectare of Fe- EDDHA). Zinc fertilizer treatments were used as application in soil and simultaneously with basic fertilizers (phosphorus and potassium fertilizers). While, iron fertilizer treatments were applied as irrigation fertilizer during wheat tillering stage. At the end of the growth season, wheat yield components (1000-seed weight, number of grains per spike, biomass weight, grain yield, number of tillers per square meter) and quality characteristics including hectoliters, seedling number, protein percentage, grain hardness and moisture content in different treatments were determined. MSTAT-C statistical software and Duncan's multiple range test were used to compare the means of the studied treatments.Results and Discussion The results showed that the interactions of zinc and iron on 1000-grain weight, number of grains per panicle and number of tillers and simple effects of zinc on total yield were significant (p< 0.01). The highest wheat grain yield was obtained in the treatment of 120 kilograms per hectare of Zn and 2.5 kilograms per hectare of iron and was equal to 6723 kilograms per hectare. The results showed that increasing one element alone had a negative effect on the number of plants per square meter. So that the lowest number of tillers per square meter (489 tillers per square meter) was observed when 60 kilograms per hectare of zinc fertilizer was consumed without iron fertilizer application. In other words, the imbalance in the amount of nutrients caused a significant reduction in the number of plants per square meter. Although the role of iron in yield and yield components of wheat in saline conditions was less than the element zinc, but the combined use of zinc and iron in a certain ratio had a positive effect on the yield components of wheat. Despite the less effect of iron application than zinc on wheat yield and yield components in saline conditions, the combined application of zinc and iron in a certain ratio had a positive effect on the wheat yield components. Combined and separate application of iron and zinc had no significant effect on wheat grain quality indicators including hectoliters, hardness and moisture. While the application of the most value of zinc caused a significant decrease in the wheat grain zeleny index. Higher levels of zinc fertilizer reduced the zeleny number of wheat grain, but the results showed that iron fertilizer levels followed the opposite trend rather than the element zinc. The least protein content (12.8%) was obtained in the treatment of 120 kg zinc fertilizer per hectare, which showed a statistically significant difference with the control treatment. Based on economic analysis, the application of 30 kg of zinc fertilizer per hectare, 2.5 kg of iron fertilizer per hectare and the combined application of both zinc and iron fertilizers resulted in a benefit-to-cost ratio of 2.3, 3.1 and 2, respectively.Conclusion Based on the economic analysis of treatments, their effect on qualitative and quantitative yield of wheat and the role of these micronutrients in human health, application of 30 kg ha-1 Zn fertilizer (as application in soil) and 2.5 kg ha-1 Fe fertilizer (as Irrigation fertilizer) in the wheat tillering stage was suggested in saline soil and climate conditions of khuzestan province.All right reserved. All right reserved. All right reserved.
Volume 43 - Issue 4
Amir Rahimi; Behnam Doulati; Saeid Heydarzadeh; Fatemeh Ahmadi
Abstract
Today, water scarcity is one of the biggest concerns of agriculture in arid and semi-arid areas. In order to investigate the effect of vermicompost, biofertilizers and nitrogen on the quantitative and qualitative performance of Badershob under different moisture conditions, a factorial experiment was ...
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Today, water scarcity is one of the biggest concerns of agriculture in arid and semi-arid areas. In order to investigate the effect of vermicompost, biofertilizers and nitrogen on the quantitative and qualitative performance of Badershob under different moisture conditions, a factorial experiment was performed in the form of a randomized complete block design with three replications. Experimental treatments, including irrigation (I) at three levels of 40, 60 and 80% moisture, can be used at the root development depth as the first factor and soil fertility at five levels: non-consumption of fertilizer (F0), urea (150 kg per hectare). Nitrogen-stabilizing release (NFB), vermicompost (V) and vermicompost + release nitrogen-fixing (V + NFB) release bacteria were applied as the second factor. The results showed that water scarcity led to a significant reduction in the amount of nutrients (zinc, manganese and copper) and photosynthetic pigments, while plants inoculated with V + NFB significantly increased the amount of zinc (Zn), manganese (Mn) and Copper (Cu) has become more fertile than soil. The combined use of V + NFB increased chlorophyll a (45%), chlorophyll b (50%), total chlorophyll (46%) and carotenoids (39%) compared to the control treatment. The content of total phenol, flavonoids, the percentage of radical inhibition of DPPH, the percentage of relative moisture content and dry yield of the plant led to an increase of 36, 37, 35, 29 and 31%, respectively, in optimal irrigation conditions and 31, 29, 30, 21 and 23%. Comparison of the average soil fertility treatments in different irrigation levels showed that soil fertility application led to a decrease in proline content. Accordingly, the highest amount of proline (31 micrograms of warmer weight) of the control treatment was observed in irrigation conditions after consuming 80% of the usable moisture in the root development depth and without the use of soil fertility treatments. However, the lowest proline levels of 15.61 micromoles per kg of body weight were obtained in irrigated conditions after consuming 40% of the moisture usable in root development depth and fertilizer and vermicompost treatment + nitrogen stabilizing release bacteria (V + NFB). According to the results of variance analysis, different irrigation levels and soil fertility treatments had a significant effect on the amount of malondialdehyde and hydrogen peroxide. According to the results of the comparison of the mean of the data, the delay in irrigation significantly increased the concentration of malondialdehyde. While the use of soil fertility treatments has shown an effective role in reducing the amount of malondialdehyde, the highest and lowest levels of this trait were observed in control treatment and combined treatment of vermicompost and nitrogen-fixing release bacteria (V + NFB), respectively. Combination treatment of vermicompost and nitrogen-fixing release bacteria (V + NFB) reduced the amount of hydrogen peroxide at all three different irrigation levels compared to the control treatment.Soil fertility combined with soil fertility treatments was less than the individual application conditions In moderate stress conditions and 21, 19, 18, 17 and 17% in severe stress conditions in plants inoculated with V + NFB. From the obtained results, it is inferred that the application of the combined system of organic, biological and chemical fertilizers due to the increase of compatible solutions and regulation of antioxidant systems, as an effective solution to soil fertility and increase nutrient uptake, improves environmental stress. Comparison of the average data obtained from the interaction of different levels of irrigation and soil fertility treatments clearly showed that the combined use of fertilizer and vermicompost + nitrogen-fixing release bacteria (V + NFB) and treatment application of vermicompost increased the effect of increasing irrigation at all different levels. The percentage of leaf moisture content showed. The lowest percentage of leaf moisture content (52.45%) in irrigation conditions was obtained after consuming 80% of the moisture that can be used in the root development depth and without the use of soil fertility treatments. A study of the results of this study showed that the combined use of vermicompost and nitrogen-fixing release bacteria (V + NFB) reduces the effects of drought stress. Many of the quantitative and qualitative characteristics of the plant are fragrant.Therefore, the results of this study showed that the use of soil fertilizers by improving plant tolerance in water stress conditions leads to improved plant performance.
Volume 31- Issue 1
N. Honarjoo; A. Alimohammadi; A.H. Charkhabi; S. Mahmoodi; A. Jalalian
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 35 - Issue 1
A. Mousavipour; M.J. Sheikhdavoodi; M. Ghanyan; Seyed N. Saeedi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 25 - Issue 1
A.A. Naseri; M. AAlimohamadi; A.R. Barzegar
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 36 - Issue 1
Yousef Abaspour Kalan; Mohammad Nikbakht; Majid Rahnama
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 23-34
Abstract
Drying grape fruit as a strategic product in Iran faces numerous challenges including color change, spoilage, and hygienic issues and long drying time. To this aim, the present research was conducted to kinetically study the thin-layer hot air drying of grape fruit together with mathematical modeling ...
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Drying grape fruit as a strategic product in Iran faces numerous challenges including color change, spoilage, and hygienic issues and long drying time. To this aim, the present research was conducted to kinetically study the thin-layer hot air drying of grape fruit together with mathematical modeling to cover the drying process. The results give a promising opportunity for an appropriate design of a dryer. Experimental setups included four levels of air temperature, 40, 50, 60 and 70 oC and air velocity of 1.2 ms-1. Ten semi-empirical and empirical models were subsequently fitted to the experimental data and statistical criteria, coefficient of determination (R2), Chi square (χ2) and Root Mean Square of Error (RMSE) were investigated. Results showed that air temperature of drying has a meaningful effect on the drying rate in a way that increasing the temperature from 50oC to 60oC led to a 59% reduction in the drying time. It was observed that the whole drying process was located in the falling drying phase. Modeling evaluation of data showed that Midili model fitted best (R2=0.9978, χ2=0.0001679 and RMSE=0.010234) to the experimental results. Additionally, the influence of air temperature on the constants and coefficients of the studied models was extensively assessed.
Volume 37 - Issue 1
Negin Hassanvandi; Ahmad Landi; Hamid Reza Matinfar; Mohammad Hassan Taherzadeh
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 23-34
Abstract
Soil salinity and salinization are destructive phenomena and limiting factors for agricultural development. Therefore, it is necessary to monitor and mange salinity. Identification of saline soils and production of saline soils maps are the first steps for their management. The objective of this study ...
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Soil salinity and salinization are destructive phenomena and limiting factors for agricultural development. Therefore, it is necessary to monitor and mange salinity. Identification of saline soils and production of saline soils maps are the first steps for their management. The objective of this study was to achieve a map of saline soils of the south of Ahvaz using ETM+ images. Soil sampling from 0-15 cm was accomplished using visual interpretations and differences in spectral reflection of various phenomena. Electrical conductivity (EC) was measured in soil paste. Spectral values of each sample were obtained in different bands and the relationship between spectral values and samples electrical conductivity was analyzed by determining correlated bands and selecting desirable bands for contributing to the model. The results showed that the correlation between electrical conductivity values with B4, B2 bands, brightness and SAVI was significant at 1% level. Using the correlation between satellite data (Landsat ETM+ 2010) and numerical value of soil salinity, salinity maps were produced in GIS. Finally, a salinity map was prepared using a multiple variable regression model. The accuracy of the produced map by electrical conductivity values showed that the correlation method in mapping soil salinity can be recommended.
Volume 32 - Issue 1
F. Mohajer Mazandarani; M.A. Asoodar
Volume 35 - Issue 2
Nasrin Zalaki Badili; Gholamabbas Sayyad; Kazem Hemadi; Samira Akhavan; Ali Abdi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 25-36
Abstract
In Iran, most mountainous watersheds do not have enough hydrometery stations and defective stations have sparse data. Because of limited availability of hydrologic data, watershed modeling plays a crucial role in development of local resources. In this study, SWAT was applied to simulate runoff in Marun ...
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In Iran, most mountainous watersheds do not have enough hydrometery stations and defective stations have sparse data. Because of limited availability of hydrologic data, watershed modeling plays a crucial role in development of local resources. In this study, SWAT was applied to simulate runoff in Marun dam (Idanak) watershed, a sub-basin of Marun catchment. Calibration and sensivity analyses were performed with SUFI-2 program. The model was run for period of 1994-2006and data of one hydrometery station at Idanak watershed were used for calibration and validation. For calibration of monthly runoff, the Nash-Sutcliffe, R2, p-factor and d-factor were 0.63, 0.73, 0.59 and 1.23 and for validation, these values were 0.70, 0.75, 0.67 and 1.05 respectively. The results showed that SWAT could be a proper tool for simulating the flow rate values of the river.
Volume 42 - Issue 4
H. Sorkheh; A. Moezzi; N. Enayatizamir
Abstract
Introduction In Khuzestan province, Iran, huge amounts of organic waste is generated annually, leading to challenges for its safe disposal, with the waste being usually either burned or land filled.Agro-industrial wastes such as sugarcane pith, have been recognized as important renewable sources ...
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Introduction In Khuzestan province, Iran, huge amounts of organic waste is generated annually, leading to challenges for its safe disposal, with the waste being usually either burned or land filled.Agro-industrial wastes such as sugarcane pith, have been recognized as important renewable sources of value-added organic products such as compost.Compost is a mixture of decayed organic material decomposed by microorganisms in a warm, moist, and aerobic environment that release nutrients into readily available forms for plant use. Recycling of organic wastes by the process of composting in agriculture brings in the much needed organic matter to the soils and improves the overall soil fertility and soil productivity Thus, composting is a process for appropriate disposal of waste and is also beneficial from ecological and economic point of view. Lignocellulosic materials are not easily degraded due to the lignin, crystalline and structural complexity of cellulose matrix. Application of chemical and biological treatments may increases waste degradation and decrease composting process time. Bacteria and fungi are the two main microbes that help in decomposition of organic waste and forces of composting. In addition, efficient composting is dependent on the microbial activity. The objective of this research was to investigate the effect of chemical (gypsum) and microbial treatments (consortium of bacteria and fungi) on reduce C/N and shortening process of compost maturity which is used in agricultural fields. Materials and Methods In this research, an incubation experiment was carried out in laboratory condition as a factorial experiment based on a randomized complete design with two factors: 1) gypsum application in three levels including, 1%, 5% and 10% w/w, and 2) microbial inoculation in four levels including control (without microbial inoculation), inoculation of substrate with consortium of bacteria, consortium of fungi and consortium of bacteria + fungi, with three replications. The sugarcane pith for compost production was collected from Dehkhoda sugarcane Agro-industry, Ahvaz, SW Iran. The sugarcane pith was initially boiled for 2h, then air-dried. Sugarcane pith samples were sterilized in an autoclave and 1% w/w urea were added to each samples to reduce their C/N ratio. Then, sterilized gypsum and microbial treatments were added to samples in plastic jars. Samples were incubated for 90 days at constant temperature of 25 ± 2 °C. Samples moisture content was maintained at 80% of field capacity. The samples were weighted every day and the required amounts of distilled water were added. At the end of incubation period, sample properties such as organic matters loss percent (OM loss), ash content, carbon (C), nitrogen (N), hydrogen (H) and sulfur (S) content were measured. Also oxygen (O) content and atomic ratio including carbon to nitrogen (C/N), hydrogen to carbon (H/C), oxygen to carbon (O/C) and hydrogen to oxygen (H/O) ratio were determined. All statistical analyses were performed using SAS software. Means of different treatments were compared using the Duncan’s test at probability level of 5%. Results and Discussion The results of variance analysis showed that the gypsum levels and microbial treatments significantly affected the organic matters loss percent, carbon, nitrogen, hydrogen and sulfur content and O/C, H/O and H/O ratio. In addition interaction effect of gypsum and microbial treatments was significant on nitrogen, hydrogen content and C/N ratio. The results indicated that the gypsum addition and inoculation of bacteria and fungi consortium to sugarcane pith significantly (P < 0.05) decreased the carbon content and C/N, H/C and H/O ratio, while significantly (P < 0.05) increased nitrogen, oxygen and hydrogen content as well as O/C ratio. With increasing gypsum levels (from 1 to 10% w/w) the carbon content and C/N, H/C and H/O ratio significantly (P < 0.05) reduced, while nitrogen, oxygen and organic matter loss percent, hydrogen content and O/C ratio significantly (P < 0.05) increased. Comparison of microbial treatments showed that consortium of bacteria + fungi had higher effect on changes in organic matter loss percent, carbon and nitrogen content and C/N, H/C, H/O and O/C ratio. Maximum organic matter lost and nitrogen content as well as minimum and C/N, H/C and H/O ratio were recorded for co-inoculation of bacterial and fungi consortium combined with application of 10% gypsum treatments. Reduction of C/N, H/O and H/C as well as increasing O/C in the above mentioned treatment, indicating that maturation of sugarcane peat composting was completed three months after composting process. Conclusion From the results of this study, it can be concluded that inoculation of consortium of bacteria and fungi with 10% gypsum led to hasten the sugarcane pith degradation and shortening composting process duration.
Volume 33 - Issue 2
Volume 34 - Issue 2
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 29-40
Abstract
The objective of this research was to design and develop an automatic device for displacing and placing the spherical-shaped fruits in the trays, with minimum damage to flesh. A planar two-degree-of-freedom tray mechanism was designed which placed the tray in the exact position when the gripper released ...
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The objective of this research was to design and develop an automatic device for displacing and placing the spherical-shaped fruits in the trays, with minimum damage to flesh. A planar two-degree-of-freedom tray mechanism was designed which placed the tray in the exact position when the gripper released a fruit. Two platforms with two independent linear motions, along perpendicular directions, were used. Finally, an electronic control system was developed to control the motion of the whole system and perform the motions in the pre-defined time sequences. Many tests on gripper, arm and tray performances were performed. In the tests, a spherical-shaped fruit such as apple with three different shapes, namely, oblong, conic and oblate were used. The results showed that the device had the ability to pick and release the oblong apples more effectively.
Volume 34 - Issue 1
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 29-42
Abstract
In recent years, many studies have been carried out on the biological changes of micaeous minerals and their potassium release by plant types and microorganisms. However, there is little information on the effect of organic matter (OM) on the biological transformation of biotite and its potassium release. ...
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In recent years, many studies have been carried out on the biological changes of micaeous minerals and their potassium release by plant types and microorganisms. However, there is little information on the effect of organic matter (OM) on the biological transformation of biotite and its potassium release. The objective of this study was to investigate the biological transformation of biotite and its potassium release influenced by organic matter treatments.A pot experiment was carried out in a completely randomized design with factorial combination and three replicates. Growth medium was a mixture of quartz sand, biotite and OM (0, 5 and 10 gr/kg cocopeat). During 120 days of alfalfa cultivation, plants were irrigated with either a complete or a K-free nutrient solution and distilled water as needed. At the end of the experiment, the dry matter of plants was determined and K uptake was measured by flame photometer, following dry ash extraction. Mica and its weathering products were separated from the quartz sand to analyze their clay fractions using X-ray diffraction (XRD). Under the K-free nutrient solution, an increase in plant dry matter and potassium concentration in shoot occurred in pots containing biotite and organic matter as compared to those with no organic matter amendment. Significant increase of plant K uptake occurred in pots containing biotite and organic matter, as compared to those without it, under both nutrient solutions treatments. XRD data showed the transformation of biotite under both nutrient solution treatments. Under complete nutrient solution, the addition of organic matter had a negligible effect on mineralogical transformation of biotite. However, under K-free nutrient solution, the addition of organic matter significantly increased the mineralogical changes.
Volume 38 - Issue 1
Maryam Jamshidsafa; Bijan Khalili Moghadam; Siroos Jafari; Shoja Ghorbani
Abstract
Introduction: Wind erosion is not only a basic geomorphic process of eroding and altering landforms but also one of the main causes of sandy desertification in arid and semiarid areas (Chepil 1945; Nordstrom and Hotta 2004). Single-grained, fine sand dunes are usually composed of none-strength materials ...
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Introduction: Wind erosion is not only a basic geomorphic process of eroding and altering landforms but also one of the main causes of sandy desertification in arid and semiarid areas (Chepil 1945; Nordstrom and Hotta 2004). Single-grained, fine sand dunes are usually composed of none-strength materials with a low water retention that make them susceptible to wind erosion. They lack organic matter and are inherently of low fertility (Ahmadi, 2002). Therefore, sand dunes and drift areas require non-oil artificial covers for their stabilization and that of the vegetation cover (Rezaie, 2009). The covering material types include oil (Rezaie, 2009), flat crop residues (Chepil, 1944; Bilbro and Fryrear, 1994), standing residues (Siddoway et al., 1965; Bilbro and Fryrear, 1994), pebble (Li et al., 2001), cotton gin trash, clay, gravel, picket fence, brush, straw, and hay (Fryrear, 1985). Soil properties including compressive strength, plasticity, compactibility, strength characteristics, elastic modulus, crushing strength, unconfined compressive strength, erodibility, shear strength, and permeability have been investigated for evaluating mulch effectiveness. Improvements have been achieved in sand dune stabilization by decreasing permeability and enhancing strength properties. The effect of soil properties on wind erosion has been studied through shear strength of soil surface which includes a frictional term (due to inter-particle frictional strength) and a cohesive term (due to intrinsic bonds among particles) (Koolen and Kuipers, 1983; Alizade, 2009). As regards the factors influencing soil shear strength, soil particle diameter, bulk density, cohesion, aggregate index, water content, crust, and organic matter have all been found to influence wind erosion (Raji et al., 2004; Homauoni and Yasrobi, 2011). Based on these observations, it may be hypothesized that soil cohesion caused by mulching operations could be effective in reducing wind erosion. Filter Cake is residue produced in huge amounts by the agro-industry that is composed of cellulosic substances, CaCO3, N, P, K, organic matter, and clay. The objective of this research is feasibility of Filter Cake using as a Khuzestan sugarcane residues for adopted-environmental mulch production. Materials and Methods For this purpose, Factorial experiments in completely random design form were conducted that factors included mulch kind(5 organic mulch and oil mulch), thickness(1 or 2 layers) and precipitation. In this study, Filter cake and clay soil samples (Albaji-Ahvaz) were used to make sugarcane mulches. A sand dune sample was selected as bed for applying the mulch. To select the right ingredient and treatments, Filter cake, clay samples were mixed with water in try and error, and producted suspension sprayed on sand dune bed. Surface surface soil shear strength, penetration resistance, soil adhesion and mulch’s internal frictional angle and erodibility were measured by shear vane, penetrometer, Zhang’s shear device, wind tunnel respectively. Results and Discussion The results determined that there is significant effect (p<0.01) on surface shear strength and penetration resistance in different much and thickness. But there is no significant effect on soil adhesion and mulch’s internal frictional angle because Zhang’s shear device hasn’t essential sensitive to differentiate them. Based on this research, Mulch 1(50g clay+150 g Filter Cake) is selected as superior mulch in Ahvaz sand dune stabilization because of higher surface shear strength and penetration resistance rate. It is defined as the resistance soil materials can offer against shear stress. This property is directly related to the cohesive and friction forces between soil particles (Koolen and Kuipers, 1983; Knapen et al., 2007; Khalilmoghadam et al., 2009) and, thereby, related to soil intrinsic properties such as clay content, salinity, and organic matter content (Horn et al., 1994). Sugarcane residues due to their effects on cohesive forces affect soil strength via the physical and chemical properties of Filter Cake. In this study, increases in SAR were found to be inversely proportional to SSS and PR. With identical values of SAR, treatments with higher EC values exhibited greater saturated SSS and PR. This shows the adjusting effect of EC on SAR effects. It is, therefore, concluded that the combined Filter Cake and clay soil could strongly affect soil resistance to erosive shearing stresses and wind erosion under environmental conditions. Conclusion Sugarcane mulches were shown to be effective in stabilizing sand dunes as compared to oil mulches. It is, therefore, concluded that the combined Filter Cake strongly influence to erode under environmental conditions.
Volume 40 - Issue 2
Soil Physics, Erosion and Conservation
Vajiheh Dorostkar; Reyhane Vali
Abstract
Introduction Crop production in arid and semi arid regions especially in saline soils always has many problems. Soil low organic matter content is one of the limiting factors in arid condition. Incorporation of plant residues is a good strategy for increasing the soil organic carbon and consequently ...
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Introduction Crop production in arid and semi arid regions especially in saline soils always has many problems. Soil low organic matter content is one of the limiting factors in arid condition. Incorporation of plant residues is a good strategy for increasing the soil organic carbon and consequently for improving soil physical quality (34). However, some studies have shown that addition of organic matter in to the soil can increase soil water repellency (17, 18). This study was conducted to investigate the effect of grape leaves and pomegranate peels on the soil structural stability and soil water repellency in different salinity levels. Materials and Methods The arable soil was collected from the soil surface layer (0–20 cm) of Bastam Agricultural Research field in Semnan province and passed through a 4 mm sieve. A greenhouse experiment was conducted with three treatments including plant residues type (Grape leaves and pomegranate peels), amount of plant residues (0, 2 and 5 g 100 g-1 soil ) and salinity (1.5, 7 and 15 dS m-1). Plant residues were collected from grape and pomegranate gardens and after drying, milled and passed through a 1 mm sieve. Plant residues were mixed with soil and salinity treatment was applied with calcium chloride salt. Pots were filled with mixture of saline soil and plant residues and incubated in the greenhouse for 50 days. The soil organic carbon, soil hot water and diluted acid carbohydrate, soil microbial basal respiration, water dispersible clay and soil water repellency were measured at the end of the experiment. Results and Discussion Pomegranate peels increased the soil organic carbon content and hot water and diluted acid carbohydrates more than the grape leaves (Table 5) due to greater C:N ratio and lower microbial decomposability (37). Soil microbial basal respiration was 15.5% lower in pomegranate peel treatments than grape leaves and (Table 5). Water dispersible clay decreased by increasing the amount of plant residues (Table 8). Soil organic carbon increased by the amount of plant residues. Soil organic carbon is an important factor in stability of soil aggregate and consequently decreases the soil water dispersible clay (7). Strong negative correlation between soil organic carbon and soil water dispersible clay can confirm these results. In addition, the soil carbohydrates are known as an important factor in stability of aggregate especially for macroaggregates (40). Salinity increment from 1.5 to 15 dS m-1 caused a reduction in water dispersible clay from 45.1 to 31.2 g kg-1 soil (Table 9). Calcium as a divalent cation is an important factor in soil structural stability and probably decreased the soil water dispersible clay (7). Soil repellency index was greater than 1.95 in all treatments and ranged from 2.3 and 5.9 in different treatments. These results indicated subcritical soil water repellency in soil. Soil water repellency index increased 38 and 67 percent in treatments with 2 and 5 g residues 100g-1 soil compared to control treatment (no residue) (Figure 3). In addition, soil hydrophobicity was 10% higher in the pomegranate peels treatments than in grape leaves treatments (Figure 4). Soil organic carbon and soil hot water and diluted acid extractable carbohydrates concentration increased by the plant residues addition. The soil organic components have a hydrophobic and a hydrophilic parts and the orientation of hydrophobic parts on the soil particle surface can make a repellent soil surface (6). Soil calcium (Ca+2) concentration increased by salinity. This divalent cation in the soil solution could act as a bridge between the soil particles and functional groups of dissolved organic matters. This bridge could facilitate covering of soil particles by hydrophobic compounds and make a more stable soil structure by flocculating soil particle at high salinity levels (7). The hydrophobic coatings on the soil surfaces increased the solid–liquid interfacial free energy (γsl) and decreased the solid surface free energy (γsg) as indirect effects of salinity on repellency. In addition, water entering into the soil immediately dissolved the soluble salts which had precipitated in the initially dry soil. There is some evidence showing that surface tension of water (γlg) increases with salts. Decrease of γsg and the increase of γsl and γlg might cause the repellency increment (43). Calcium bridge between soil particles could improve the soil structure with salinity increment. Increasing the SE by salinity in this study confirms this hypothesis. The soil SW depends on pore geometry and hydrophobic coating on soil particles, but the soil SE only depends on pore geometry. Thus, increasing the SE might be an indicator for better pores connection and stable structure (15). Conclusion Many grape leaves and pomegranate peels are produced in Iran every year. These plant residues are potentially a good source for increasing the soil organic carbon. Our results showed that incorporation of these plant residues in to the soil could increase the soil organic carbon and carbohydrate concentration and improve the soil aggregates stability. However incorporation of residues into the soil increased the soil water repellency. In addition salinity increment induced soil hydrophobicity. More detailed studies are needed to understand the positive or negative effects of this subcritical hydrophobicity development in saline soils.
Volume 41 - Issue 1
Design and Evaluation of Agricultural Machines
Davood Kalantari
Abstract
Introduction Tillage is a main operation for seedbed preparation and is one of the major items of energy and cost expenditure in crop production. In the conventional rotary tillers, using the L-shape blades has numerous problems such as severe vibrational problems, weeds wrapping around the blades, ...
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Introduction Tillage is a main operation for seedbed preparation and is one of the major items of energy and cost expenditure in crop production. In the conventional rotary tillers, using the L-shape blades has numerous problems such as severe vibrational problems, weeds wrapping around the blades, and lower performance due to the limited power of such small tillers. Therefore in order to overcome the addressed problems, design, fabrication and evaluation of a new rototiller adapted for small farms and gardens were considered in this research. Materials and Methods To start the design, the power requirement was estimated using a semi-theoretical model for the given working depth, working width, forward and rotational speed of the machine. Then a suitable engine was chosen based on the estimated power. The estimated power was 3.4 kW (4.5 hp); therefore, according to the available engines in the market for single cylinder gasoline engines, a Kato engine with 5.5 hp power and maximum speed of 3600 rpm was chosen. By reducing the rotational speed of the engine in three stages, rotational speed of the rotor was obtained in the range of 140-260 rpm. To transmit the power from the engine to the rotary axis, first, a pulley and belt mechanism (two V-shaped belt, type B) and then two chain mechanisms (roller chains 40 and 60) were used. Rotary axis with the diameter of 2.5 cm was made from steel E295. The fabricated rototiller has a working width of 60 cm, working depth of 7 cm, rotational speed between 140-260 rpm, forward speed equal to the operator’s translational speed, and maximum power equal to 5.5 hp. The maximum force exerted on each of the blades was calculated equal to 84.10 kgf (824.73 N) using the theoretical approach proposed by Bernacki (1972). In the next step, numerical simulation of blades, flanges and rotating shaft for stress and strain analysis was performed using the Ansys software. Farm experiments were carried out as split plots in citrus gardens based on randomized complete block design with three replications. The soil moisture content as the main plot varied in two levels (13.5-21.9 and 21.9-30.3 percent based on dry weight) and the rotational speed of blades as subplots varied in three levels (140-170, 170-200 and 200-230 rpm). The measured parameters consisted of clod mean weight diameter, soil relent percentage, soil bulk density and specific fuel consumption. To determine the diameter of aggregates, a set of standard sieves with the diameter ranging from 0.5 to 8 mm were used. Then a laboratory shaker was used to sift the samples. Each sample was shaken for 30 sec. To determine the fuel consumption during the experiments, the filled fuel tank method was used. Data analyses including analysis of variance (Anova), mean comparisons and interaction between the parameters were performed using the SPSS 16 software. Results and Discussion The numerical stress analysis of the flange showed that the maximum van - Mises stress occurred in the position of the blade-flange connections, with a magnitude of 52.98 MPa for the given working conditions, including soil engineering properties, working depth and other important parameters. The experimental results obtained in this study indicated that influence of soil moisture and rotational speed of blades on the clod mean weight diameter, soil relent percentage and specific fuel consumption were significant (p < 0.01). The clod mean weight diameter was measured equal to 8 mm at high rotational speed (200-230 rpm) and high soil moisture content (21.9%-30.3%) and equal to 15 mm at low rotational speed (140-170 rpm) and low soil moisture content (13.5%- 21.9%). The maximum soil relent percentage was obtained equal to 97% at high rotational speed (200-230 rpm) and high soil moisture content (21.9%-30.3%). Regarding the results obtained in this study, the specific fuel consumption increased first in a light slop, then in a steep rise with increasing the blades rotational speed. The reason can be the higher relent percent of the soil at higher rotational speeds and higher moisture contents, albeit at the examined range of 21.9-30.3. The specific fuel consumption was maximum at higher soil moisture content, i.e., 30 %. The results indicated that the blades rotational speed and soil moisture content had no significant effect on the field efficiency of the examined rototiller. Reduction of the rotational speed of the rototiller from high-to-moderate speeds yields decreasing the fuel consumption of 17 liter/ha, which could be significant in a wide scale soil tillage operations. As a general result, reduction of the rotational speed has some considerable advantages such as reducing the power requirements, reducing the blade wearing and maintaining the soil structure. Conclusion The stress analysis of the fabricated machine together with the experimental and field measurements indicated that the new proposed and fabricated blades were a suitable choice for construction of small rototillers. The fabricated machine with the new blades showed some additional advantages including less specific energy consumption, less weeds wrapping around the blades, and less vibrational problems.
Volume 41 - Issue 3
Soil Biology, Biochemistry and Biotechnology
Maryam Talebi Atouei; mohsen olamaee; REZA GHORBANI NASRABADI; seyed alireza movahedi Naeini
Abstract
Introduction Salinity is the most important challenge in arid and semi-arid regions. Salt stress, ionic and osmotic components, like other abiotic stresses, lead to oxidative stress that damage cellular membranes, nucleic acids, oxidizing proteins, and causing lipid peroxidation through overproduction ...
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Introduction Salinity is the most important challenge in arid and semi-arid regions. Salt stress, ionic and osmotic components, like other abiotic stresses, lead to oxidative stress that damage cellular membranes, nucleic acids, oxidizing proteins, and causing lipid peroxidation through overproduction of reactive oxygen species (ROS). Antioxidant capacities and osmolytes play a vital role in protecting plants from salinity that causes oxidative damages. Applying biological methods such as using of halotolerant plant growth promoting rhizobacteria (PGPR) is very important to reducing the harmful effects of salinity on plants. Also exopolysaccharide production by plant growth-promoting strains helps in binding cations, including Na+, and thus decreases the content of Na+ available for plant uptake. This is especially useful for alleviating saline stress in plants. Biochar can also alleviate the negative impacts of salt stress in crops. Biochar can enhance plant growth either by its direct or indirect mechanisms of actions. The direct growth promotion relates to supplying mineral nutrients, such as Ca, Mg, P, K and S etc., to the plant, whereas, indirect mechanisms involve improving soil physical, chemical and biological characteristics. Materials and Methods In this research, the effect of halotolerant plant growth promoting bacteria, biochar and gypsum was investigated on enzymatic and non-enzymatic defense mechanisms of barley such as Catalase, Superoxide Dismutase, Proline and Membrane stability under salinity stress. The experiments were carried out as a factoria with a completely randomize design in greenhouse conditions for 2016-2017. The factors included: bacteria (without inoculation (T0), bacterial isolate T5 (megaterium Bacillus), bacterial isolate T17 (licheniformis Bacillus ), biochar (0 and 5percent w/w), gypsum ( 0and 50 percent gypsum requirement ) and soil leaching (without and leaching with) with three replications. The activity of catalase (CAT) was determined by changes in absorbance at 240 nm (IUg−1FW) (Aeby, 1984). Superoxide dismutase (SOD) activity was determined by nitroblue tetrazolium (NBT) reduction, according to Minami and Yoshikawa (1979) and the enzyme activity was expressed as (IUg−1FW). Proline content was estimated according to Bates et al., (1973) and expressed as µ mol g−1 fresh weight (FW). Membrane stability was estimated according to Sairam and. Saxena (2001). All statistical analyses were performed using SAS software. The means of different treatments were compared using LSD (P ≤0.05) test. Results and Discussion The results showed that using halotolerant bacteria and biochar reduced the activity of antioxidant enzymes in barley plants. This reduction was higher in the treatment containing bacteria T17 (Bacillus licheniformis) biochar and with leaching. Also, inoculated plants with both bacteria had the highest concentration of proline, which was significantly higher in the treatment containing bacteria T17 (Bacillus licheniformis) biochar and gypsum. Also, application of halotolerant bacteria, biochar and gypsum improved the membrane stability of plant. This increase has been remarkable in inoculated treatments with T17 bacteria (Bacillus licheniformi) in saline soil with leaching associated with 50 percent gypsum requirement Conclusion Generally, results showed that halotolerant bacteria, biochar and gypsum can be used as a tool for reducing adverse effects of salt stress. Inoculation of soil with these bacteria has helped in alleviating saline stress by changing several physiological, enzymatic, and biochemical agents in plant. Bio-remediation of salt affected soils is one of the cheap and eco-friendly approaches for remediation of salt affected lands as the traditional physical and chemical techniques are becoming costly. The plant growth promoting halotolerant bacteria helps in Bio-remediation of salt affected soils and thereby improving the agricultural crop yields. Incorporation of biochar into salt-affected soil could diminish salinity stress by decreasing soil bulk density, increasing in soil cation exchange capacity, potassium and calcium concentrations, water holding capacity and nutrient and water availability in soil. Also, bichar due to high organic matter content can play a dramatic role in salt affected soil with organic compound defficiency. According to these amended features of biochar in soil, we suggest, more experiments conducted by biochar with different material and ratios under saline - sodic soils.
Volume 33 - Issue 1
Volume 41 - Issue 4
Soil Genesis and Classification
Mansooreh Khaleghi; Azam Jafari; Mohammad Hadi Farpour
Abstract
Introduction Soil digital mapping represents a set of mathematical computations to predict the distribution of soil classes in the landscape. This approach relies on statistical relationships between measured soil observations and environmental covariates at the sampling locations. The need for digital ...
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Introduction Soil digital mapping represents a set of mathematical computations to predict the distribution of soil classes in the landscape. This approach relies on statistical relationships between measured soil observations and environmental covariates at the sampling locations. The need for digital soil mapping as an addition to conventional soil surveys results from a worldwide growing demand for high- resolution digital soil maps for environmental protection and management as well as projects of the public authorities. Digital soil data is increasing based on new processing tools and various digital data. The digital identification of soils as a tool for creating soil spatial data provides ways to address the growing need for high-resolution soil maps. The main objective of this study is to generate the digital soil map based on the legacy soil data. Materials and methods The study area is located in southeastern Iran, 330 km from Kerman city, in Faryab distinct. In this study, a Latin hypercube sampling design was applied and the sampling was done according to the difference in landforms (geomorphology map), topography (including digital elevation map) and geology. The geographic locations of 70 profiles were identified. Soil profiles were described according to U.S. Soil Taxonomy (Soil Survey Staff, 2014) and finally, the soil samples were taken from their diagnostic horizons. The collected soil samples were transferred to the laboratory, and some physical and chemical analyzes were performed based on routine standard methods. Environmental data include the parameters derived from the digital elevation model, Landsat satellite images (remote sensing indexes), geology map, geomorphic units (geomorphology map) and legacy soil map of the study area. All environmental variables were derived using ENVI and SAGA software. In this research, a multinomial logistic regression model was used to predict soil classes and the modeling was done in two scenarios: 1- modeling without the legacy soil map and 2- modeling with the legacy soil map. Estimation of predictive accuracy of soil classes was also done using the overall accuracy index and Kappa coefficient. Results and discussion The result of the modeling with the multinomial logistic regression method in two sets of input variables showed that the topographic position index is the most effective variable in predicting soil classes. This confirms topographic importance on soil genesis in the studied area. After topographic variables, the legacy soil data is an effective parameter in modeling. The legacy data of soil is a strong and valuable database for predicting soil characteristics. The old soil map consists of the salt surfaces and Inceptisols order. Unlike the hot and arid climate of the study area, Inceptisols order was identified in the old soil map. Soil survey with very small scale was probably led to generalization of the studied soils and hiding the main soils of the study area. However, the small-scale mapping and the presentation of different soils in the region do not prevent the presence of the old soil map as an important predictor. It seems that there is a high concordance between the borders of old soil map and the described soils diversity in the study area. The matching and concordance between the boundaries of the old map and the described soil profiles help the model to differentiate different soils, although the correspondence between the soils type of the old soil map and the observed soils can play a more effective role in predicting by the model. Soil legacy information is a powerful and valuable database for predicting any feature of the soil. In both predicted maps, four major groups of Haplosalids, Haplocambids, Haplocalcids and Torriorthents were identified. The great group of Torriorthents is located in the north of the region and in the alluvial fan landform. Haplosalids great groups were most commonly found in clayey surfaces. Haplocambids and Haplocalcids great groups are located more in the geomorphic surface of the cultivated fan and the piedmont plain, respectively. The results of the predictive quality of the logistic regression model showed that the number of well-estimated soils in the presence of the old soil map is more than when there is no old soil map in the modeling. In addition, the results of the validation of the models showed that the map accuracy and kappa index increased in presence of the legacy soil map. As a result, the model's validation indices including the map purity and Kappa index increased from 0.47 and 0.16 to 0.63 and 0.43, respectively. In both models, the highest accuracy of the estimation was obtained for Haplocambids great group. Conclusions The results showed that topographic position index was the most important and powerful variable for forecasting in both models, and confirms that topography or relief is the most important soil forming factor in the study area. Using the legacy soil map as one of the environmental variables in modeling, efficiency and accuracy are more accurate than modeling without the legacy soil map. If the old soil maps as legacy information are used in digital soil mapping, the similarity and matching of the soils of the studied area shoud be cheched even with the very small scale because the high concordance leads to rational prediction, and random and chance predictions do not occur.
Volume 37 - Issue 2
M Khorramian; S. Boroumand Nasab; F. Abbasi; S. R. Ashrafizadeh
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 33-45
Abstract
This study was conducted to assess the ability of LEACHN model for predicting nitrate and ammonium in the soil profile under corn at the Safiabad Agricultural Research Center, over two growing years. Three irrigation levels (50, 75, and 100% water requirement) and three nitrogen fertilizer levels (150, ...
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This study was conducted to assess the ability of LEACHN model for predicting nitrate and ammonium in the soil profile under corn at the Safiabad Agricultural Research Center, over two growing years. Three irrigation levels (50, 75, and 100% water requirement) and three nitrogen fertilizer levels (150, 225, and 300 kg N ha-1) were applied through fertigation in three equal splits during the first irrigation, 6 to 8 leaves, and before flowering stages. The results of model calibration showed that nitrification and denitrification rates with 0.17, 0.004 per day and a dispersion coefficient equal to 200 mm provided the minimum mean bias error (MBE) and the maximum modeling efficiency (EF). Therefore, the MBE and EF values for nitrate varied from -2.09 to 3.89 and -0.1 to 0.88 respectively. However, model predictions for NH4 mobility through the soil profile were lower than that of nitrate mobility. Comparison between predicted and measured values did not show nitrate leaching below 60 cm in the soil profile in any treatments. Statistical indexes of MBE, EF, and coefficient of variation (CV) for soil moisture content predictions in different depths varied between 0.003 and 0.019, 0.24 and 0.73, and 5.8 and 17.9% respectively showing the high accuracy of model in prediction of soil moisture content.
Volume 39 - Issue 2
Energy and Renewable Energies
M Mozafari; A Ghazanfari Moghadam; H Hashemipour Rafsenjani; A Atae
Volume 42 - Issue 1
Mohammad Reza Bakhtiari; Ghasem Asadian
Abstract
Introduction The cleaning operation is an important process to increase the seeds’ purity degree. Cleaning is the most fundamental task in a cleaning machine, which separates the impurities of the healthy seeds. In a research that was conducted by Chenari et al. (2013), The efficiency of three ...
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Introduction The cleaning operation is an important process to increase the seeds’ purity degree. Cleaning is the most fundamental task in a cleaning machine, which separates the impurities of the healthy seeds. In a research that was conducted by Chenari et al. (2013), The efficiency of three types of wheat cleaning machines, R-Machine, Cimbria, and Gold-Saat, was investigated. The results of the statistical analysis showed the Cimbia machine had the greatest cleaning efficiency (86.72%). The R-Machine and Gold-Saat had 80.64% and 81.59% total efficiency, respectively. In this study, the effects of three different cleaning machines were evaluated on the seed losses percentage and seed cleaning percentage of all outputs in various pre-cleaning and cleaning machines for cleaning wheat seeds. Materials and Methods In this study, three types of various cleaning systems were investigated to study their performances on wheat cleaning rate in Hamedan Province. Generally, a cleaning system is constructed of 5 parts: (1) pre-cleaning machine, (2) cleaning machine, (3) Trieurs, (4) weighting system, (5). packaging system. In this study, the term cleaning system refers to only the first and the second part of the cleaning system. The cleaning systems in the study were (Table 1): (1) R-Machine with pre-cleaning machine model ARS2000, made in Iran, (2) Ram-Sanat with pre-cleaning machine model RAM200, made in Iran, and (3) Gold-Saat with pre-cleaning machine model GS100S, made in Germany. Table 1 shows the characteristics of three different cleaning systems, containing cleaning and pre-cleaning machines. Fig. 1 shows a schematic of the inputs and outputs of the wheat cleaning system (containing pre-cleaning and cleaning machines with Trieurs). Some factors were considered and determined as the following: (1) theoretical and practical capacity in ton/ha: based on the factory’s manual, the theoretical capacity for pre-cleaning machine and cleaning machine were 20 and 5 tons/ha, respectively; whereas, the practical capacity was calculated 2.2 tons/ha for total system (pre-cleaning machine and cleaning machine); (2) purity percentage of wheat input: this factor was determined for the pre-cleaning machine as follows: purity percentage of healthy seeds input = (weight of healthy seeds / total weight) × 100; (3) loss percentage of all outputs in the pre-cleaning machine, loss percentage of all outputs in the cleaning machine, and the total loss percentage of the system, as below: Loss percentage of each of output on the cleaning system = (weight of lost seeds / total weight) × 100. A completely randomized design was used in the research and Duncan’s test was used to compare the means results. Results and Discussion Table 2 shows the means of different parts of cleaning systems (containing pre-cleaning and cleaning machines) by Duncan’s method. Thus: Pre-Cleaning Machine: Wheat input impurity or purity percentage: Table 2 indicates non-significant differences between wheat input impurity and purity percentage as affected by various wheat input to the cleaning system. Loss percentage in the second suction of the pre-cleaning machine: Table 2 indicates significant differences between loss percentage in the second suction of the pre-cleaning machine. The maximum loss percentage belonged to Ram-Sanat, and the Gold-Saat had the minimum amount. Cleaning Machine: Loss percentage in suction: the result shows significant differences between loss percentage in primary and final suction of the cleaning system. Loss percentage in sieves of the cleaning machine: Table 2 indicates significant differences between loss percentage in the top of the upper sieve and below th downer sieve of the cleaning machine. Loss percentage in barely cleaning and semi-wheat cleaning parts: based on Table 2, a significant difference between them is observed. The maximum losses belonged to Ram-Sanat, and the R-Machine had the minimum amount. Cleaning System (Pre-Cleaning and Cleaning Machine Combination): Purity percentage of wheat output (last purity): the results of the analysis of the variance show that all cleaning machines have the seed final purity percentage greater than 98%. Total loss percentage of the system: the results show that the total loss percentage of Gold-Saat, R-Machine and Ram-Sanat are 6.04%, 2.97% and 4.4%, respectively. Also, the results show that seed loss is zero for meshed cylinder, but the wheat loss of pre-cleaning and cleaning machines for all outlets is significant (p < 1%). These results are in agreement with Safarzadeh, (1993) and Jilanchi et al., (1997). Conclusion The results show that all three cleaning machines have the final purity seed percentage greater than 98%, and also the minimum wheat loss (3.0%) belonged to Ram-Sanat cleaning machine. The R-Machine and Gold-Saat had 4.4% and 6.0% total loss.
Volume 42 - Issue 3
A. R. Jafarnejadi; S. M. H. Mousavifazl; M. javadzadeh
Abstract
Introduction In spite of problems in providing timely and adequate water supply, the inefficient water use efficiency in agriculture as the most important consumer of freshwater is one of the most important challenges and issues in the agriculture. The knowledge of soil physical properties and water ...
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Introduction In spite of problems in providing timely and adequate water supply, the inefficient water use efficiency in agriculture as the most important consumer of freshwater is one of the most important challenges and issues in the agriculture. The knowledge of soil physical properties and water retention have main rolled on soil water application management. This research was conducted to determine the soil physical and chemical properties affecting the soil water retention capacity in calcareous soils series in Khuzestan province. Materials and Methods From the nine dominant series in the different regions, five disturbed soil samples and the same number of undisturbed soils were collected from 0-20 cm depth. Soil physical properties including soil texture, bulk density were measured. Moreover, soil water characteristic curve was measured at five points (0, 330, 1000, 5000 and 15000 cm) using pressure plate and pressure membrane devices. The van Genuchten equation was fitted on the measured soil water characteristic curve data. In addition to soil physical and hydrological properties, soil salinity as electrical conductivity (EC), pH and lime (TNV) were also measured. Results and Discussion The results showed that the soil pH varied in the range of 7.1 - 7.6, EC variation range was 2.43 - 47 dS m-1, sand, silt and clay contents varied in ranges of 18 - 40%, 32 - 50% and 20 - 44 %, respectively, TNV was 48 – 60 % and the values of soil bulk density were in the range of 1.14 - 1.52 g cm-3. The studied soils were calcareous (TNV value of all studied series was more than 45 %) and had moderate to heavy texture including loam (55 % of studied soil series), silty clay loam (23 %), clay loam (11 %) and clay (3 %). The water content at field capacity (corresponding of soil suction of 330 cm) and permanent wilting point (corresponding of soil suction of 15000 cm) varied from 32 to 56 % and 16 to 26 %, respectively. There are significant correlation between clay content with the soil moisture at both field capacity and permanent wilting point. The most salinity was observed in south east of Ahvaz (loam), south Ahvaz (loam), Khoramshahr 2 (clay) and Khoramshahr 1 (loam) series. The values of soil available water in studied calcareous series were varied as Khorramshahr 2 (0.30 cm3 cm-3) > Ahvaz-Hamidiyeh (0.22 cm3 cm-3) > Khorramshahr 1 (0.189 cm3 cm-3) > Ramhormoz-Rustamabad 1 (0.177 cm3 cm-3) > Ramhormoz-Bazidi (0.165 cm3 cm-3) > South of Ahwaz (0.16 cm3 cm-3) > South east of Ahwaz (0.134 cm3 cm-3) > Ramhormoz- Rustam Abad 2 (0.119 cm3 cm-3) > Shadegan (0.102 cm3 cm-3). The results showed that van Genuchten equation had suitable fit on studied soils of dominant calcareous series. The studied soil samples from the south of Ahvaz with the highest bulk density (1.55 g cm-3) and high salinity (33.5 dS m-1) had the highest value of the van-Genuchten parameter (n) which indicates more uniform distribution of the soil pore volume. In spite of the high ability of Khorramshahr 2 series in soil water retention, based on the coefficients of van Genuchten equation and measured soil water characteristic curve, it can be argued that this soil probably has severe aeration limitation. Conclusion The result showed that salinity and bulk density were important properties that affect the ability of soil water retention and availability in the studied soil series. Extensive water retention capacity in the soil (10 to 30 %) indicates the need for different irrigation management operations in each of the studied soil series. The highest value of soil densities were observed in south of Ahvaz, Ramhormoz-Bazidi and Khorramshahr series, indicating soil degradation in studied areas due to inappropriate cultivation management practices. Moreover, the results showed that the experimental parameters of the van Genuchten equation have a physical concept and can be found useful information on the soil ability to water retention and some other soil physical properties. The results of this research confirmed that there is a significant difference in the ability of soil water retention in the dominant calcareous soils series of Khuzestan province which indicates the necessity of proper understanding of soil hydraulic properties for irrigation management in farms, increasing water use efficiency.
Volume 43 - Issue 1
seyyed jafar hashemi; Ramzan Hadipour rokni; Mehdi Khoshdel
Abstract
Introduction Weeds are any plant growing at wrong time in the wrong place and also harmful for crops”.Weeds compete with the crop for nutrient and light therefore reduce crop yield. Weed management is a strategy that makes a desired plant population successful in a particular agro-ecosystem using ...
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Introduction Weeds are any plant growing at wrong time in the wrong place and also harmful for crops”.Weeds compete with the crop for nutrient and light therefore reduce crop yield. Weed management is a strategy that makes a desired plant population successful in a particular agro-ecosystem using knowledge of the ecology of the undesired plants that is the weed. Recently several ways of controlling weeds are using by farmers, either by using manual, chemical, mechanical or biological means. The earliest and the simplest weed control method is manual weed control. The most effective method of weed management is by making physical contact with the weeds themselves, which are using mechanical weed control machine to reduce the chemical pesticides in mechanized paddy field. This method is among the most important goals in achieving sustainable agriculture development. The present weeding machines have been some demerit which includes of inefficiencies in different farm conditions and the lack of cost-effective purchasing for Sub-ownership land. Therefore to increase of weeding operation quality, the new weeding machine was designed as a single row with rotor propeller by solid work software and manufactured. The weeding unit has been ability to mount on the portable weed cutting machine useable in upland.Materials and Methods The weeding machine consists of various parts, including of gasoline engine, final drive gearbox, a power transmission shaft and a weeding unit. The weeding unit consisted of chassis, power transfer shaft, propeller, plastic skateboard and protective frame. The diameter of weeding propeller is 22 cm with two blades, which the rotary shaft passes through it. For determination of maximum torque, a total of 9 samples were selected from different areas of paddy field with high weed density and then measured. The maximum propeller torque was determined by torque meter (TQ-8801) through the shaft .The power requirement was calculated about 0.6 hp. So, the gasoline engine with 1.1 kW and 3000rpm was used in designed weeding machine. The gearbox reducer is mounted with a ratio of 1 to 10 after the clutch system was used to provide the rotor rotation at about 200-300 rpm and connected to the engine clutch. The machine field capacity was obtained about 5000 to 7500 m2 per day (10 hours). The actual field operation of weeding machine was evaluated on a 200 m2. The fields was separated into 4 plots and 4 treatments was used in each plots as follow; control (T1), manual weeding (T2), once weeding by machine (T3) and twice weeding at the same time (T4). Data was collected 35 days after transplant (15 days after weeding operation) for each treatment. The height of plant, hill number and efficiency of machine was measured in a completely randomized design with three replications and analyzed by SAS software.Results and Discussion Based on the requirements of paddy field, the single rotary weeding machine was designed and manufactured. The technical data was obtained based on the computation. The technical results show that the maximum static torque was measured 0.47 N.m. The value of the shaft angle curve designed to be around 0.11 degrees which is very small. Therefore, by consideration of some factors such as; physical ability, fatigue caused by operator's work and unpredicted losses time, the field capacity was obtained about 0.5 to 0.75 ha/day. The results of evaluation experiment showed that there was a significant difference between the treatments at the probability level of 1%. The height of plant was increased in twice weeding treatment (T4) about 19%, manual weeding (T2) about 12%, and once weeding by machine (T3) about 4% in compare of control treatment (T1). The hill numbers was increased in twice weeding treatment about 44%, manual weeding about 40%, and once time weeding by machine about 15% in compared with witness treatment.Conclusion The product performance is highly correlated with the hill number. There is a meaningful difference between mechanical weeding and manual weeding. In comparison of mechanical weeding methods, the hill number increased about 4% in twice weeding method in compare of once time weeding which shows no meaningful effect. Therefore, once time mechanical weeding (T3) is economically better due to the coexistence of yield with twice weeding (T4). Also, the hill number is increased about 29% in once mechanical weeding in compare of manual weeding. Eventually, once time weeding by machine was recommend.
Volume 47 - Issue 1
Soil Chemistry and Pollution
Alireza Abdollahpour; Mojtaba Barani Motlagh; Amir Bostani; Farshad Kiani; Farhad Khormali; REZA GHORBANINASRABADI
Abstract
Introduction Soil organic carbon (SOC) is the largest source of terrestrial organic carbon and small changes in its components have many effects on global warming and carbon cycle. Soil organic matter (SOM) is considered as the most complex and least known component of soil, because it consists of plant, ...
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Introduction Soil organic carbon (SOC) is the largest source of terrestrial organic carbon and small changes in its components have many effects on global warming and carbon cycle. Soil organic matter (SOM) is considered as the most complex and least known component of soil, because it consists of plant, microbial and animal masses in various stages of decomposition and is a mixture of heterogeneous organic materials that are closely related with mineral components. Soil organic matter has beneficial effects on the chemical (buffering and changes in pH) and biological (precursor and supply of nutrients for microbes) properties of the soil and thus affects the fertility capacity of the soil. The quality and quantity of soil organic matter is the most important criterion for sustainable soil management. Total organic carbon (TOC) consists of labile and non-labile forms of SOC and have different degrees of sensitivity to different types of land use changes and management operations. The purpose of this research is to investigate the effect of changing land use on the chemical components of soil organic carbon and carbon recalcitrant index in Toshan Watershed, Golestan provinceMaterials and Methods For this research, four major and dominant types of land use were considered in the study area, including forest, cropping land, garden and abandoned lands in the Toshan watershed in the northwest of Gorgan city of Golestan province. The soil organic carbon and total C of soils were measured. Furthermore, the soil carbon fractionation was performed by Young's method (using hydrolysis methods with HCl and Labile fraction). In this research, Acid hydrolysis method was used to separate the recalcitrant SOM pool. For this purpose, one gram of SOM sample was treated with 25 ml of 6 M hydrochloric acid solution at 105°C for 18 hours in a Pyrex tube in a hydrolysis package. After cooling, the remaining non-hydrolyzed materials were separated by centrifugation. Then, they were dried in an oven at a temperature of 60 degrees Celsius and considered as a part of resistant organic matter. The resistant part of the soil organic carbon was determined with the CHNS Analyzer device. The Labile fraction consists of water soluble carbon, microbial biomass carbon and mineralizable carbon are measured using the following methods and the labile part of carbon is calculated from their sum. Water-soluble organic carbon is extracted by adding 20 ml of distilled water to 10 grams of wet soil. The mixture will be shaken and centrifuged, filtered. Then they will be quickly analyzed by TOC Analyzer. Microbial biomass carbon will be determined by the chloroform fumigation-extraction method. Mineralizable carbon determined as follow. The amount of CO2 will be measured by titration of NaOH solutions with 0.1 M HCl in the presence of BaCl2. Cumulative amount of CO2-C emitted in 30 days of incubation is called Mineralizable carbon. The data were analyzed based on the factorial test in the form of a completely randomized design (CRD) with two levels of soil depth and four land uses with five replications. Correlation between traits was also estimated. Statistical analyzes were performed using SAS software. Therefore, it can be concluded that depending on the climatic conditions and the condition of the soil, the forest, in terms of natural cover, the correct management of agricultural lands (using modern methods of no-tillage or low-tillage) can be a potential practice. It is to store carbon in the soil as well as various soil components and increase soil formation, which will subsequently reduce the concentration of carbon dioxide in the atmosphere.Results and Discussion The results showed that the first depth of forest use has the highest amount of total carbon and soil organic carbon (6.12% and 3.5% respectively). Also, the highest amount of resistant organic carbon (HCl hydrolysis), water-soluble organic carbon, microbial biomass carbon, and microbial mineralizable carbon were observed in forest land use. The second depth (10-20 cm) of forest land use had the highest and the second depth (10-20 cm) of garden land use had the lowest organic carbon resistance index (82.1% and 50.17%, respectively). In all land uses, except for the forest, the soil organic carbon resistance index decreased with increasing sampling depth. Due to the fact that the carbon management index can be easily calculated, it can be a suitable index for quick assessment of soil quality.Conclusion The results showed that with the change of land use and cultivation, the soil organisms received more oxygen and the speed and intensity of respiration in the soil increased in the short term, which caused more decomposition of organic matter and with the decrease of organic matter in the long term, the quality of soil decreases after a while.
Volume 36 - Issue 2
Amin Nasiri; Hossein Mobli; Shahin Rafiee; Keramat Rezaei
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 37-48
Abstract
Thyme is one of important medicinal plants that have been used since the past. This plant has many properties in the treatment of diseases, especially infectious diseases, thyme and its components are used in various industries such as pharmaceutical, food, cosmetics and health. In order to maintain ...
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Thyme is one of important medicinal plants that have been used since the past. This plant has many properties in the treatment of diseases, especially infectious diseases, thyme and its components are used in various industries such as pharmaceutical, food, cosmetics and health. In order to maintain the quality and quantity of essential oil extraction of plant drying process has a great role in the processing of medicinal plants. An important aspect of the drying technology with the aim of selecting the most appropriate drying method is mathematical modeling of the process. Therefore in this study, thin layer drying behavior of thyme (Thymus vulgaris L.)was experimentally investigated in a convective type dryer and the mathematical modeling performed by using adaptive neuro-fuzzy inference system (ANFIS). The drying experiments were conducted at inlet drying air temperatures of the 40, 50 and 60⁰C, at three drying air velocities of 1, 1.5 and 2 m/s. For kinetic model simulation of thin-layer drying of thyme, four ANFIS models were used, and to generate the fuzzy inference system model, the two partitioning techniques, grid partitioning and subtractive clustering, were used. Results indicated that ANFIS model could satisfactorily describe the drying curve of thyme. Also, comparison of the results of the two partitioning techniques showed that subtractive clustering technique was found to be the most suitable for fuzzy inference system generation for predicting moisture ratio of the thin layer drying of thyme.
Volume 38 - Issue 2
H. Shamsaldin; V. Jalali; A. jafari
Volume 40 - Issue 1
A.A. Safari Sinegani; S. Taheri Ghahrizjani
Volume 42 - Issue 2
Soil Chemistry and Pollution
Hasan Bolbol; Majid Fekri; Majid Hejazi-Mehrizi; Naser Bromand
Abstract
Introduction Phosphorus (P) is an essential nutrient for all forms of life on the earth, but in excess concentrations, it can act as a serious water pollutant through eutrophication. Thus, it is very important to remove P from aqueous solutions before their release into natural water resources. Among ...
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Introduction Phosphorus (P) is an essential nutrient for all forms of life on the earth, but in excess concentrations, it can act as a serious water pollutant through eutrophication. Thus, it is very important to remove P from aqueous solutions before their release into natural water resources. Among the various P removal techniques that have been developed, the sorption process is widely accepted to be an effective water treatment technique because of low cost, ease of operation, simplicity of design, and high sorption capacity in dilute solutions. Layered double hydroxides (LDHs) are a type of two-dimensional nanostructure anionic clays with high capacities to sorption of anions. These non-silicate clays consist of positively charged brucite-like octahedral sheets which neutralize by a negatively charged interlayer containing relatively weak bonded anions and water molecules. The positive charges generated by the isomorphous substitution of trivalent cations for divalent cations are balanced by interlayer anions that can be exchanged by other anions making them good anion-exchangers with high selectivity. LDHs have been widely used as environmental sorbents because of their high charge density, large interlayer areas, good thermal stability, and high anion exchange capacities of the interlayer anions. The aim of the present study was to synthesize a Mg-Fe LDH as a sorbent for P removal from aqueous solution. Materials and Methods The Mg-Fe LDH was synthesized using the co-precipitation method. In brief, a mixture solution containing 0.03 mol MgCl2. 6H2O, and 0.01 mol FeCl3. 6H2O was added dropwise into a flask containing 100 ml of 1 M NaOH solution under vigorous stirring at pH=10. The obtained slurry was filtered and washed repeatedly with DW until the filtrate pH reached neutral. Mg-Fe LDH particles were then obtained by drying the filtrate at 70 °C in an oven overnight. The crystallinity of the sample was studied using X-ray diffraction (XRD) analysis. In order to investigate the performance of the synthesized LDH as a P sorbent, batch experiments were carried out in polyethylene centrifuge tubes. The suspensions were shaken for 24 hours at 250 rpm, and the supernatant was then separated by centrifugation at 4000 rpm for 10 minutes and were filtered by Whatman ashless grade 42 filtration papers. Equilibrium P concentration was determined according to the ascorbic acid method using UV-vis spectrophotometer at the wavelength of 880 nm. The effects of pH, initial P concentration, and contact time on P sorption were investigated in the ranges of 2-10, 0-300 mg/L and 0-1440 min, respectively. Results and Discussion The XRD pattern of the LDH sample showed typical structure of hydrotalcite-like compounds with sharp and reflection peaks corresponding to the (003), (006), (012), (015), and (110) crystal planes which are characteristic planes of hydrotalcite-like compounds. The efficiency of LDH to remove P decreased with the increasing of initial P concentration and the maximum removal efficiency of LDH occurred in the range of 5-20 mg/L of initial P concentration. With increasing of initial P concentration from 20 to 300 mg/L, the P removal efficiency of LDH decreased from 98.7 to 24.6 %. The P removal efficiency was increased with time and reached equilibrium at 60 min. The P removal rate of LDH in this time was about 66 % and no significant decrease in residual P concentration was observed after 60 min. The sorption of P on LDH was highly pH dependent, and the maximum P removal was found at pH of 4. The sorption kinetic and isotherm data were well described by pseudo-second-order and Langmuir equations, respectively. According to the Langmuir equation, the maximum P sorption capacity (Qmax) of LDH was obtained as 13.96 mg/g. Conclusion It was found from the results of this study that the mechanisms involved in the P sorption onto LDH included electrostatic attraction, ligand exchange, and surface complex formation. In addition, the results suggested that the synthesized Mg-Fe LDH can be potentially used as an effective sorbent for the removal of P from aqueous solutions. Further research is needed on the regeneration of the LDH after P sorption and the evaluation of desorption behavior of P from LDH under different conditions.
Volume 39 - Issue 1
N. Hafezi; M. J. Sheikhdavoodi; S. M. Sajadiye; M. E. Khorasani Ferdavani
Volume 44 - Issue 1
Mohsen Soleymani; Vahid Jahangiri Boltaghi; Mohammad Javad Sheikhdavoodi; Zabihollah Mahdavifar
Abstract
Introduction: Biogas, a product of anaerobic digestion of biomass resources, is one of the major renewable energies with the potential to replace fossil fuels. Anaerobic digestion is performed under specific conditions and according to a specific chemical process. Sugar cane is one of the most common ...
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Introduction: Biogas, a product of anaerobic digestion of biomass resources, is one of the major renewable energies with the potential to replace fossil fuels. Anaerobic digestion is performed under specific conditions and according to a specific chemical process. Sugar cane is one of the most common sources of sugar and bioethanol production in the world. In the ethanol distillation process, large quantities of vinasse are produced. The direct consumption of vinasse as fertilizer has many environmental problems. Anaerobic digestion of vinasse is a potential solution to such environmental problems. Factors affecting the performance of an anaerobic digester can be classified into three main categories: (1) raw material characteristics, (2) reactor design, and (3) operating conditions. Among the operating conditions, temperature and pH are the most important parameters, so in this study, these two parameters were investigated.Materials and Methods:The main raw material was vinasse. Some other additives were used to alter its chemical properties. To have a proper substrate composition, the ingredients before loading into the digesters were evaluated for their chemical and physical properties, including pH, concentration and C/N ratio. The bovine rumen contents of 10% of the final volume of input material were added to supply methanogenesis bacteria as well as to modulate the (C/N) ratio.The Total Solid Content (TS), Volatile Solid (VS) and Chemical Oxygen Demand (COD), were evaluated before and after digestion.A series of batch reactor were used to perform the experiment. The experiment was carried out in a split plot design in a completely randomized design. The main and sub-factor was respectively temperature (at four levels of 30, 35, 40 and 45 ° C) and pH (at four levels of 6.8, 7, 7.2 and 7.4), and the experiment was performed in three replication.To measure the volume of gas produced, a 50 ml water tank connected to the digester outlet as a U-tube was used. The amount of water movement in the U-shaped tube is an indicator of the volume of biogas produced. For better detection of water displacement, some color was dissolved in water. Passing the gas produced from the three-molar NaOH solution, its impurities (mainly carbon dioxide) were absorbed, and the resulting pure gas was re-measured using a U-shaped tube. Using the law of complete gases, the biogas volumetric index was converted to the standard gas volume and finally converted to values based on (ml/gVS) and the new values were analyzed by analysis of variance and mean comparison.Results and Discussion:Almost all main and interaction effects on all the factors studied were significant at the 1% probability level. The amount of gas produced increased with increasing temperature but with increasing pH, it first increased and then decreased. The amount of gas produced at 35, 40 and 45 °C was not significantly different. So because of economic and energy constraints, an operating temperature of 35 °C is recommended for anaerobic digestion of vinasse. The graph of the interaction of temperature and pH shows that at higher temperatures the rate of gas production increases with increasing pH. Although the highest gas volume was obtained at pH of 6.8 and 7.4, but the gas produced in the pH range of 7–7.2 was more pure. Therefore, the best combination of pH and temperature to produce the highest and purest gas is 7 and 35 °C, respectively. But since the vinasse produced in the alcohol factories has high temperature and therefore higher temperatures are possible, so 40 °C is also recommended.It was also clearly observed that the smaller the volume of gas produced, the greater its purity.The VS-R factor is also more sensitive to temperature changes than to pH changes. Thus, in anaerobic digestion of vinasse, pH control is more important than temperature control. VS-R performs best at pH 7. This factor was not significantly different at 35, 40 and 45 °C. Therefore, considering the cost of providing more heat at temperatures of 40 and 45 °C compared to 35 °C, 35 °C is the best temperature for manure production with the highest volatile organic matter removal.The COD-R process was similar at all pHs. COD-R at pH 7 was higher at all temperatures than at other pHs. It was also significantly higher at 40 and 45 °C, compared to other temperatures. So like other factors, the best pH and temperature based on this factor are 7 and 40 °C, respectively.Conclusion According to all factors studied, the best pH and operating temperature of anaerobic digestion of sugar cane vinasse is 7 and 35 ° C, respectively. Another important conclusion to be drawn from this study is that changes in all parameters studied are affected by pH changes rather than temperature changes. Therefore, sufficient care must be taken to ensure that pH variations in the anaerobic digestion medium be very low and around the range proposed (about 7).
Volume 46 - Issue 1
Plant Nutrition, Soil Fertility and Fertilizers
Mehri Bazi abdoli; M Barani; abdolamir Bosatni; Taleb Nazari
Abstract
Introduction Various biomass sources such as crop residues have been proposed as feedstock for biochar production . Meanwhile, a large quantity of crop residues (rice) is produced as waste and they are either burnt or piled and abandoned at some locations in the fields. Burning of crop residues is resulting ...
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Introduction Various biomass sources such as crop residues have been proposed as feedstock for biochar production . Meanwhile, a large quantity of crop residues (rice) is produced as waste and they are either burnt or piled and abandoned at some locations in the fields. Burning of crop residues is resulting in substantial loss of nutrients, and may lead to air pollution and human health problems . An alternative approach is to apply crop residues to soil in the form of biochar. Bioavailability of nutrients exclusively micronutrients (Fe, Zn) isa serious problem in soils having high pH which ends in crops yield to decline and ultimately can lead to malnutrition in humans. The biochar modification with acid may increase the solubility of nutrients (P, , Fe, Zn, Cu,,Mn) present in biochar, thereby significant improvement in mineral nutrition of plants grown in calcareous soils. In the other hand, One of the ways to use and exploit saline lands is to use salinity-tolerant cultivars, such as the Quinoa (Chenopodium quinoa) plant. It is known that biochar increases soil pH, which may result in less availability of phosphorus and other micronutrients, such as Fe, Zn, and Mn, in alkaline and calcareous soils. Therefore, modifying biochar with acids can increase the availability of nutrients in biochar for different plants grown in calcareous soils. The objection of this study is to investigate the effect of normal biochar and acid-modified biochar from rice residues on the yield and yield components of quinoa plants (Gizavan number) in a calcareous soil affected by salt.Materials and Methods The soil used in the study was collected from 0-30 cm depth which passed through via 2-mm sieve after air-drying and its chemical and physical properties were determined. To achieve the aim of this study, the factorial experiment was carried out in a completely randomized design in 4 replications. Factors include 3 types of rice biochar (unmodified, modified by pre-acidic method and modified by post-acidic method) and different levels of biochar (0, 2, and 5% by weight). Then 10 quinoa seeds were planted in each pot at 2 cm depth which after the plant emerging and greening declined to 3 plants in each pot. The pots were randomly moved twice a week during growth to eliminate environmental effects. Irrigation and weeding operations were done by hand. After the end of the growth period (187 days), the plants were harvested. So vegetative growth parameters and yield components including shoots fresh and dry weight, plant height, stem diameter, panicle length, number of leaves, number of lateral branches, and 1000 grain weight were measured and then biological yield and harvest index were determined. The statistical results of the data were analyzed using SAS software (9.4) and the LSD test (at 5% level) was used for comparing the mean values.Results and Discussion As a result of adding biochar to soil, it becomes alkaline. Chemical modification of biochar using strong acids can reduce soil pH and improve the fertility of calcareous soils and increase vegetative parameters and yield components of quinoa. Based on the obtained results, the interaction effect of different types and levels of biochar on all investigated traits was significant at the level of 1%. The results showed that the highest height, fresh and dry weight, panicle length, number of lateral branches, and stem diameter were related to the 5% post-acidic rice biochar treatment and the lowest value was related to the control treatment. furthermore, the results showed that the highest amount of plant dry weight of 8.82 gr/pot, the height of 77.50 cm, and 1000 seed weight of 17.3 gr/pot was obtained from the treatment of 5% post-acidic rice biochar, compared to the treatment of 5% Unacidified rice biochar had an increase of (81.97), (56.77), (32.17) and (7.06) percent respectively. As a result of the high dry weight of shoots and the 1000 seed weight, the 5% post-acidic rice biochar treatment provided the highest biological yield at 16.05 and harvest index at 45.03.Conclusion Under the conditions of this study, acid-modified biochars (post-acidic and pre-acidic) enhanced vegetative growth characteristics and yield components of quinoa plants in calcareous soils affected by salt. Therefore, it is recommended to prepare biochar from acidic sources or to modify it with post-acidic and pre- acidic methods.
Volume 41 - Issue 2
Land Evaluation and Suitability
Javad Givi; Hojat Dialami; Mehdi Naderi Khorasgani
Abstract
Background and objective: In the assessment of land suitability, the land-production capacity is identified and the type of use is determined in proportion to that capacity. In this regard, the FAO approach has been used by many scholars in different parts of the world and Iran in land suitability assessment ...
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Background and objective: In the assessment of land suitability, the land-production capacity is identified and the type of use is determined in proportion to that capacity. In this regard, the FAO approach has been used by many scholars in different parts of the world and Iran in land suitability assessment studies. In this approach, the most commonly used method is the parametric method. The FAO approach uses Boolean logic to assess land suitability. This logic has been criticized by a number of land evaluation researchers. Because it does not take into account the continuous nature of the soil variations along the earth's surface and the uncertainty in the measurements. To overcome these shortcomings, the fuzzy analytical hierarchy process (FAHP) was presented to determine the land suitability classes. Land suitability should be determined based on a fuzzy analytical hierarchy process, in which, unlike the FAO method, unequal importance for different land characteristics and continuity of soil variations are considered. This research was carried out with the aim of qualitative land suitability evaluation in Dashtestan area, Bushehr province for Kabkab date palm (Phoenix dactylifera L. cv Kabkab) plantation, using two methods of FAO parametric (second root formula) and fuzzy analytical hierarchy process (FAHP) and comparing these two methods. Materials and methods: The study area is located in Dashtestan region, Bushehr province, Iran; between latitudes 29º 12΄ and 29º 31΄ N and longitudes 51º 09΄ and 51º 59΄ E. Its surface area is 23000 ha. The mean annual rainfall in the area is 250 mm and its mean annual temperature is 27 °C. The soil temperature and moisture regimes are hyperthermic and ustic, respectively. The physiographic unit which is river alluvial plain is very gently sloping. 80 % of the Kabkab date palm plantation is present in the study area. In order to achieve the objectives of this research, 50 date palm groves, each with an area of at least 0.5 ha and a palm of Kababab cultivar, aged 20 to 25 years, with the same management level and having different soil, were selected as observation points. Then a soil profile was dug randomely in each date palm grove, with dimensions of 1.5 (length), 1 (width) and 1.5 (depth) meters and described, using soil profile description guide. Soils were sampled from different horizons of the profiles and the required physical and chemical analyses were carried out on the samples, according to the standard laboratory methods. The drilling site was chosen to have a date palm tree in each of the four corners of the profile. The yield of the four trees located in four corners of each profile was measured and their average yield was considered as the final yield for the corresponding profile. Meteorological data was collected for a 10 year period from the nearest synoptic station (Borazjan station, Borazjan, Bushehr). Land indices were calculated, using soil and climatic data and parametric (second root formula) and fuzzy AHP methods. Weighted average of the climatic and the soil data was used and finally a land index was calculated for each soil profile. In the fuzzy AHP method, relative weight of each of the studied criteria was determined by analytical hierarchy analysis with establishment of pair wise matrix. Degree of membership for each soil and climatic criteria was also determined through membership functions and finally, land suitability classes were determined. At the end, accuracy of the methods was also compared. Landscape characteristics such as slope, drainage and soil depth were not considered in the land evaluation, because these characteristics did not show any limitation for the date production in the study area.Results: The results of qualitative land suitability evaluation based on fuzzy AHP method showed that 96.6 and 3.4 percent of the studied area are classified as S2 and S3, respectively. This is in the case that based on parametric (second root formula) method, 82 and 18 percent of the studied area are marginally suitable and non-suitable, respectively. According to these results, higher land suitability classes were obtained, based on fuzzy AHP than through parametric method. Correlation between the calculated land index and the measured yield, determined for the fuzzy AHP method was higher than the one obtained for the parametric method. This proves that the fuzzy AHP is a more appropriate method for land suitability assessment for Kabkab date palm plantation in the studied area than the parametric method (second root formula).Conclusion: According to the results of this research, the fuzzy AHP is a more appropriate method for qualitative land suitability evaluation than the parametric method (second root formula) for Kabkab date palm plantation in the studied area in Bushehr province.
Volume 45 - Issue 2
N moallemi; Esmaeil Khaleghi; Abas Danaeifar
Abstract
Acacia with the scientific name Acacia salicina is a tree or shrub from the leguminous family and a nitrogen fixer. This species is native to dry areas in southern Australia. In some areas, this species is used as a source of fodder for livestock, for ornamental purposes, and for revival areas without ...
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Acacia with the scientific name Acacia salicina is a tree or shrub from the leguminous family and a nitrogen fixer. This species is native to dry areas in southern Australia. In some areas, this species is used as a source of fodder for livestock, for ornamental purposes, and for revival areas without vegetation. Climate change is one of the most important concerns of the world's growing population. Drought is one of the most important abiotic stresses that affects the nutritional status of plants. Stresses constantly affect the growth and development of plants, which are considered the most important factors of yield reduction in the world. Stresses are the result of abnormal physiological processes that are caused by one or a combination of biological and environmental factors, and drought is one of the most important abiotic stresses that affect growth and performance, as well as this Stress can cause plant death and limits approximately 25% of agricultural production. One of the most common ways to withstand drought stress is the use of super absorbent polymers. Commercial superabsorbent polymers are hygroscopic materials similar to sugar, and the shape of these polymers must be maintained after absorbing water and swelling. They don't have harm for soil, plants and environment. Considering the increase in temperature and pollution the purpose of this research is the effect of using three types of super absorbent polymers to increase N.P.K. absorption, water retention, reduce irrigation, reduce costs and improve the growth of acacia plants under drought stress conditions for cultivation in areas free of vegetation in Khuzestan to contrast with fine dust. In order to improve the nutritional status of acacia, a research was conducted using three types of superabsorbent polymers in three concentrations at three levels of drought stress in a factorial format in a completely randomized block design with three replications in the agricultural faculty of Shahid Chamran University of Ahvaz. The results showed that the use of superabsorbent polymers significantly increases the amount of nitrogen, potassium and phosphorus absorption by leaves, stems and roots. The concentration of 2 g/kg of A200 hydrogel in the first week increased leaf nitrogen by 12.85%, leaf phosphorus by 17.64%, stem nitrogen by 50.29% and root nitrogen by 4.96%. In the first week, SNF superabsorbent had the highest amount of potassium in stem and phosphorus in the root. Among the hydrogels, SNF superabsorbent polymer had the highest amount of phosphorus in the stem in the second week and a concentration of 1 g/kg, and this increase was significant compared to some treatments, and the lowest amount of phosphorus in the stem were obtained s in the treatment of the first week and a concentration of 0 g/kg Super absorbent polymer A200 and SNF. Increasing the concentration of super absorbent polymers increased the amount of phosphorus in the stem in most cases. increase in the intensity of drought stress caused a decrease in the amount of leaf nitrogen compared to non-stressed conditions, so that the lowest amount of nitrogen was obtained in the third week of treatment with SNF superabsorbent polymer at a concentration of 0 g/kg, which caused a decrease of 29.04% compared to the control. The increase in the severity of drought stress caused a decrease in the amount of phosphorus in leaves compared to the first week, so that the lowest amount of phosphorus was obtained in the second week in the concentration of 2 g/kg of SNF,which had a decrease of 52.94% compared to the control. intensity of drought stress and increasing the frequency of irrigation caused a decrease in the amount of nitrogen in the stem, so that the lowest amount of nitrogen was obtained in the third week and the concentration of 0 g/kg of Barbari hydrogel, which was a 32.16% decrease compared to the control. The lowest amount of root phosphorus was obtained in the third week of treatment with a concentration of 2 grams per kilogram of Barbarii superabsorbent polymer, which caused a decrease of 54.54% compared to the control. Based on the results of this research, the use of A200 superabsorbent polymer compared to other hydrogels had the greatest effect on the nutritional status of the plant and the absorption of N.P.K elements.
Volume 46 - Issue 2
Soil Biology, Biochemistry and Biotechnology
Morvarid HemmatiTabar; Setareh َAmanifar; Elaheh Vatankhah; Elham Malekzadeh
Abstract
Introduction Nickel (Ni) is a fundamental micronutrient in plants but hampers plant growth and metabolism at elevated levels in the soil. Ni toxicity to plants is manifested mainly by the decrease in germination efficiency, the inhibition of growth and root branching, damage to the photosynthetic apparatus, ...
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Introduction Nickel (Ni) is a fundamental micronutrient in plants but hampers plant growth and metabolism at elevated levels in the soil. Ni toxicity to plants is manifested mainly by the decrease in germination efficiency, the inhibition of growth and root branching, damage to the photosynthetic apparatus, and the induction of oxidative stress. In recent years, the use of arbuscular mycorrhiza (AM) has gained importance for its role in enabling plants to tolerate Ni toxicity. However, information about their effectiveness in alleviating Ni stress is scanty. The process of element transport in plants may be assumed to be different among heavy metal concentrations in the substrate. Consequently, whether AM fungi enhance the metal transport to shoots (phytoextraction) or immobilize them in the roots (phytostabilization) mainly depends on metal concentration in the substrate. Moreover, Ni has been reported to compete with other micronutrients for absorption sites, which would trigger different changes of elements concentrations. The aim of this study was to investigate the role of AM fungus in alleviating Ni stress and its possible function in plant nutrition.Materials and Methods In this study, the effects of mycorrhizal inoculation of corn plants with Claroideoglomus etunicatum on alleviation of Ni impact on plant were evaluated. Some growth characteristics of the plant, phosphorus content, micronutrients (iron, zinc, and copper), concentration of nickel in shoot and root, and Bradford reactive soil glomalin (BRSG) were assessed. Accordingly, a two-factor experiment (AM inoculation × Ni levels) in completely randomized design was done. The factors included the different concentrations of nickel (control (Ni0), 50 (Ni50), 100 (Ni100) and 250 (Ni250) mg kg-1), and the levels of fungal application (control without inoculation (NM) and inoculated with C. etunicatum (AM)). Plants were grown in the greenhouse for 90 days and then the growth parameters were recorded. The concentration of phosphorus was measured spectrophotometrically and the concentration of iron, zinc, copper, and nickel in digested plant samples was determined by ICP-OES. Bio-concentration factor and translocation factor were also calculated. The colorimetric method was used to quantify Bradford-reactive soil glomalin. The Bradford protein assay was utilized to determine the concentration of easily extractable and total Bradford-reactive soil glomalin using bovine serum albumin (BSA) as a standard.Results and Discussion Increasing the nickel concentration in soil decreased the dry weight of root and shoot, and this decrease was significant in both inoculated and non-inoculated plants at Ni250 treatment (p≤0.05). Plants inoculated with AM fungus showed significantly higher height and dry weight of shoots than plants without inoculation (p≤0.05), but the effect of mycorrhizal inoculation on the dry weight of roots was not statistically significant. The effect of nickel on the colonization percentage of roots and easily extractable Bradford-reactive soil glomalin (EE-BRSG) was significant. EE-BRSG was higher at all levels of nickel in inoculated plants than in non-inoculated ones. Moreover, with the increase of nickel concentration in soil up to 100 mg Kg-1, total Bradford reactive soil glomalin (T-BRSG) increased. The concentration of phosphorus in the shoots and roots of inoculated plants was higher than in non-inoculated plants. Mycorrhizal inoculation significantly increased the concentration of zinc and copper in the aerial part. Moreover, nickel treatment did not show a statistically significant effect on the concentration of copper in the aerial part and iron in the roots. Inoculation with AM fungus showed a significant impact on the nickel concentration of the shoots and roots, and the concentration of nickel in the roots of inoculated plants at Ni250 level was significantly higher than plants without inoculation by 29% (p<0.05). Mycorrhizal plants had lower nickel concentrations in the aerial part at Ni100 and Ni250 by 30% and 33% respectively, compared to the NM plants. The translocation factors in inoculated plants at Ni100 and Ni250 levels were significantly lower than that in non-inoculated plants, which indicates the role of fungi in preventing the transfer of nickel to the aerial parts and its accumulation in the roots. Moreover, inoculated plants in the Ni100 and Ni250 treatments showed a significantly lower bio-concentration factor by 36% and 22%, respectively, compared to non-inoculated plants.Conclusion The results showed that AM colonization can help to reduce the toxicity of nickel by increasing plant growth and uptake of phosphorus, zinc and copper. AM colonization had a prominent impact in preventing the nickel transfer to the aerial parts and its accumulation in the roots. It seems that AM fungi can be used for phytostabilization of heavy metals in soils.
Volume 44 - Issue 2
Amir Parnian; Hossein Beyrami; Kianoush Behrahi
Abstract
Introduction lack of water and soil salinization are two main threats to the sustainability of agriculture, especially in arid and semi-arid areas same as most parts of Iran. High evaporation in arid and semi-arid regions drive the down-to-up salt movement into the soil profiles and led the soil to salinization. ...
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Introduction lack of water and soil salinization are two main threats to the sustainability of agriculture, especially in arid and semi-arid areas same as most parts of Iran. High evaporation in arid and semi-arid regions drive the down-to-up salt movement into the soil profiles and led the soil to salinization. Soil salinity reduces plant production through many ways like reducing water and nutrient uptake, ion toxicity, change in soil microbial activity, carbon and nitrogen ecological cycle disruption, etc. There are many ways to control the soil salinity and preserve soil water by application of mulch is one of them. Actually the use of mulch on soil in agriculture is mainly to limit evaporation, improve water use efficiency, and weed control. Many tupes of mulch are using to control the soil evaporation such as tephra, sand, plastic, wheat straw, geotextile, etc. Organic mulches have two main disadvantages, the ecological problem and, biological pollution for agricultural areas. More than one million tons of sugarcane bagasse produce in the Khuzestan province of Iran as the agricultural waste. And composting is a proper way to reduce the bad effects of raw organic material. This study examined a soil organic mulch, produced by composted sugarcane bagasse, in Jofeir area haloculture pilot in Khuzestan province. Materials and Methods. This study, conducted in the southwest of Khuzestan province, Iran. The mean temperature during the experiment was 44 ± 2 ᵒC and the relative humidity was 65 ± 3%. The composted sugarcane mulch in 4 different thicknesses of 0.5, 1, 2 and, 0 (control) cm with 3 replicas applied on 2.5 liters of the local silt-clay-loam soil. The micro-lysimeters were 3 liters PVC pots which have heat-insulated and fill with the soil in 25 cm depth. In addition, The weight of the pots were measured at 10:00, 12:00, 14:00, 16:00, and 18:00 houres after the soil saturation. Before and after the experiment soil EC (1:2), bioavailable B concentration, saturation extracts Na concentration, and exchangeable sodium percentage (ESP) of the top 5 cm of the pots was examined. The experiment re-conducted in 5 continuous days and Identification of significant differences was performed using one-way ANOVA, in which p < 0.05 is considered significant in differences. Statistical analysis was performed with the Microsoft Excel 2010 and SPSS Version 16.Results and DiscussionResults showed the significant difference between treatments with and without soil mulch in available water loss. The lowest water loss was belonging to the treatment with 2 cm (198.6 g of water/pot) of sugarcane composted mulch. The non-mulched soil had the highest evaporation amount (407.7 g of water/pot). water loss percentage showed the same trend and reduction with increasing in the sugarcane composted mulch thickness. Which with 2 cm of the mulch the moisture loss percentage calculated about 9.8 % and it near half of the value for the control (no-mulched soil) one. This mulch able to increase the available water for plant uses. Salts, B, and Na accumulation in surface soil appeared due to the evaporation process and mulch prevents it. As the results represented, with increasing the sugarcane composted mulch thickness, EC rising was slow. The EC increase in surface section of the non-mulched soil was high (20.5 dS/m) and the final EC were 41, 32, 25.5, 22 dS/m respectively in 0, 0.5, 1, and 2 cm of the mulch thickness treatments. This effect of sugarcane composted mulch could save the plant roots from salinity effects such as high Na, B and ESP. Also, it may play a positive role in water preservation in horticulture and green space. According to the composting process, this mulch has less ecological adverse effect than other organic raw materials. On the other hand, it able to release carbon and nutrients to enhance soil biological activity which would help plants to grow well.Conclusion Results showed increasing in the water losses and salinity accumulation in the soil surface of the treatments with decresing the mulch thickness. Also, the same trend was observed for bioavailable B concentration, saturation extract Na concentration, and ESP of the soil surface. Evaporation and, as the result salinization of the soil surface, decreased by the time but, the salt transport was very fast and the high considerable amount moved to the top
Volume 43 - Issue 2
Omid Ahmadi; Parisa Alamdari; Moslem Servati Khajeh; Hossein Rezaei
Abstract
Introduction planning is essential for increasing production per unit area of strategic agricultural products. In this regard, land suitability evaluation is one of the most important key steps. While the FAO framework for land suitability evaluation is the most commonly used method, to overcome problems ...
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Introduction planning is essential for increasing production per unit area of strategic agricultural products. In this regard, land suitability evaluation is one of the most important key steps. While the FAO framework for land suitability evaluation is the most commonly used method, to overcome problems related to vagueness in definition and other uncertainties, methods such as Micro LEIS system models can be useful. Terraza, Cervatana and Almagra are the models of Micro LEIS package that are used to evaluate land suitability for agricultural activity. Considering the limitations in water resources required to produce this strategic product, the present research focuses on evaluation of Khodaafarin region lands suitability by Micro LEIS models for this utilization type. Materials and Methods This research was carried out in an area of about 16555 ha in Khodaafarin, an important region in agricultural production, located in East Azerbaijan province, northwest of Iran. The major geological formation is composed of Quaternary sediments with sandstone. According to climatic data from Khomarlo synoptic weather forecasting data station, the average annual precipitation and temperature of the region are 281 mm and 14.7 °C, respectively, and the soil moisture and temperature regimes are Aridic border to Xeric and Thermic. The study area was divided to 11 land units by geopedology method. In each land unit, a soil profile was dug, described and sampled for physico-chemical analysis. After preparing soil samples in the laboratory, soil physico-chemical routine analyses, which are important in soil classification and evaluation, were completed by standard methods, and then studied soils were classified by the 12th edition of soil taxonomy. To conduct land suitability investigations, three models of Micro LEIS package including Terraza (to determine bioclimatic deficiency), Cervatana (to determine land capability) and Almagra (to determine the suitability evaluation of the studied area) were used. Finally, according to adopted models, land capability and suitability class and sub-class were determined in actual and potential condition for sugar beet, and their maps were prepared by Arc Map 10.2. Results and Discussion According to the results obtained from description of soil profiles and physical and chemical analyses, soils can be classified as a different family of Aridisols and Entisols on the basis of USDA soil taxonomy system. Based on the Terraza model, bioclimatic deficiency class for the studied utilization type is C3 (h2-f3) or h2 moisture deficit and f3 frost risk classes, whose combination leads to C3 final class. This class revealed that during the growth period, 2-5 months annually the temperature goes under biological zero and production would decrease by 20 to 40%. Therefore, it is recommended to have safe irrigation and frost risk management. The results of Cervatana model indicated that for slope, climate, erosion and soil limitations with various degrees, 77.01% of the study area was placed in S2 land capability class. Also, 18.16% and 4.83% were classified as S3 and N1 classes, respectively. Among the above-mentioned factors, soil depth limitation was identified as the most restrictive and climate as the mildest one all over the study area. According to S2 class suggested by the Almagra model, 82.98% of the study area is acceptable for this utilization type. Suitability class for 7.62% of the study area is S3, which would increase the costs. Also, 9.4% of the study area is never suitable for sugar beet due to intensive limitation of soil useful depth and texture, which leads to S5 class. The nature of the limiting factors in land units suggests that they might be resolved. Based on this fact, in 19.64% of study area suitability class can shift to the upper one due to land improvement, while in 22.99% of the study area it is impossible for such a shift. In other parts, although some of the limitations can be solved, land suitability class remains stable and only their sub-class changes. Conclusion Considering land evaluation and the nature and professional use of Micro LEIS system models, Terrraza, Cervatana and Almagra models should be used hierarchically. Hierarchical use of models can help reduce costs because it is designed as a multiple-stage approach of land evaluation that assesses various biophysical properties of lands step by step. Accommodation of the values related to the studied land properties within the specified range presented in the models indicates that these models are calibrated for evaluating this utilization type in north-west of Iran. Therefore, traditional evaluation systems can be replaced by Micro LEIS system. According to the obtained actual and potential suitability class for sugar beet, it seems that it is a reasonable utilization type in the study area. Land improvement does not have a significant effect on the rise of land suitability class and profitability; nevertheless, it is recommended to have pilot land improvement programs to find factors which might have been ignored and might bring about further limitations.
Volume 44 - Issue 3
shayan hajinajaf; shaban ghavami jolandan; Hassan Masoudi
Abstract
Investigation of effective factors on water production system using land coolingAbstractIntroduction Water scarcity has been a worrying issue and one of the obstacles to economic growth of countries, despite various water supply sources such as groundwater, seas, rivers and rainfall. Today, in many parts ...
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Investigation of effective factors on water production system using land coolingAbstractIntroduction Water scarcity has been a worrying issue and one of the obstacles to economic growth of countries, despite various water supply sources such as groundwater, seas, rivers and rainfall. Today, in many parts of the world, due to the scarcity of water resources, disputes over access to water resources have crossed national borders and access to these resources has become a strategic goal in the interaction between countries. According to statistics released by the World Resources Institute in recent years, about 35 countries will face water stress in 2040, of which Iran ranks 13th. Considering the average rainfall in Iran and also considering the amount of water resources and per capita consumption in the country, Iran is considered among the countries that are at risk of lack of physical water resources. The purpose of this study was to provide safe water for domestic use and drinking water without using fresh water sources and only with the benefit of the air humidity. In fact, the goal is to provide fresh water from the humidity, especially for remote areas and villages with small populations that do not have access to water. In this method, there is no need to use fossil and electrical energy and only wind energy, air humidity and depth of the earth are the factors of its production, and so it is also economically viable. The system considered in this research reduces the air temperature and cools it until the saturation phase by blowing the outside hot air into a buried pipe underground. In this way, some part of the air moisture is separated and appeared in the form of water droplets on the pipe wall; then the obtained water is stored in a tank and used. Materials and Methods In this research, a system was used that was partly underground and partly out of the soil. Buried sections include the copper pipes, the circuit breakers and connections, and a water tank and the sections on the ground include a cubic chamber with dimensions of 2×2 m, temperature and humidity sensors, fans, inlet air supply section, valves control levers, air conditioners, heaters and humidifiers. During the tests, the temperature and humidity inside the chamber were controlled by a microcontroller board and the effect of changes in air humidity (30, 50, 70 and 90%), air temperature (20, 30, 40 and 50 °C), inlet air flow (2.5, 5 and 7.5 m3/h , equal to the speeds of 1, 2 and 3 m/s , respectively) and the pipe effective length (2 and 4 m with a fixed diameter of 30 mm and a thickness of 1 mm) on the amount of extracted water was evaluated. The burial depth of the pipe was about 1 m and the soil temperature was measured by a sensor next to the buried pipes. The used statistical design was the split plots design in the form of completely randomized blocks and the results were analyzed and compared using SPSS software. In order to create and control different atmospheric conditions inside the chamber, it was necessary to consume electrical energy, while in the open space water can be produced from this system without the need for electrical energy.Results and Discussion the studied factors, including the pipe length, air humidity, air temperature and air flow rate (inside the pipe), affected on the amount of produced water significantly. By increasing of the air humidity, the air flow rate, the chamber air temperature and the pipe length, the amount of produced water was increased. The air temperature of 50 °C, the air velocity in 3 m/s, the humidity of 90% and 4 m length of the copper pipe had the maximum water production in a certain period of time.Conclusion The results of the present study show that water production from air humidity can be used as a method to produce fresh water, especially in remote and low populated areas with high air humidity that do not have access to the fresh water. Although the volume of water production by this method is not comparable with methods such as the multi-stage distillation, but it is economical and does not require any energy.
Volume 43 - Issue 3
Fatemeh Moradi Ganjeh; Rasoul Meamar Dastjerdi; Mokhtar heidari; Mohammad Hadi Movahednejad
Abstract
Introduction Citrus are one of the major agricultural production available in the world and it is one of the popular fruits in the diet. The most well-known varieties of citrus fruits include oranges, lemons, grapefruits and tangerines. Cultivation of sweet lemon requires specific climate situation that ...
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Introduction Citrus are one of the major agricultural production available in the world and it is one of the popular fruits in the diet. The most well-known varieties of citrus fruits include oranges, lemons, grapefruits and tangerines. Cultivation of sweet lemon requires specific climate situation that it is found in many region of Iran. However, the high quality ones are in Jahrom, Ghsre Shirin, Dezfool, Jiroft and the Sorth of Iran. Two major limitation of long-term storage for citrus fruits are decay caused by pathogens, especially fungi, skin fruit damage and water loss, which can cause wrinkles and reduce product marketability and consumer acceptability. Edible coatings are one of the most effective methods to maintaining the fruit quality. Today edible coatings can preserve citrus quality and provide attractive approach to satisfactory performance. Chitosan is used for film or edible coatings to extend the shelf life of foods such as fruits, meat and fish and foods. The results of several studies indicate the effective role of chitosan in controlling fruit during storage. Wax in the fruit is used to prevent moisture loss and wrinkle of the fruit and also to maintain the appearance of the product and its marketability. So, the final goal of this study is investigate the effect of edible coatings (chitosan-clay Nano composite, Wax coatings and olive oil) on some quality attributes of sweet lemon during shelf life storage.Materials and Methods Sweet lemon's fruits (216 N.) were harvested randomly from a citrus orchard in Dezfool, Iran. The samples immediately sent into the laboratory for storage after necessary treatments. All fruits were disinfected by immersion in 4% chlorox for 3 minutes and then dried. Chitosan with low molecular weight (43 KD) was bought from Sigma Aldrich Company. Clay was purchased from Sefid Sang Aligoodarz Company in Iran and wax coating was provided from Pooshesh Hayat sabz company in Iran. The chitosan-clay coating was prepared by dissolving a mixture of chitosan (3w/v% to solution), clay (5, 10 and 15% wt to chitosan) and glycerol (10v/w% to chitosan) and tween 80(5% v/w to chitosan) in acid lactic solution (2%). Nano structure of chitosan-clay nano-composite was approved by XRD analysis. The chemical parameters of fruit juice such as TSS (%), pH(%) and TA (%) of lemon juice were measured. TSS was determined by digital refractometer (model MA882, made in Japan). pH was measured by pHmeter ( portable p-755 model) and TA was determined by AOAC standard method. The experiment was performed at three levels of chitosan-clay nanocomposite, olive oil, Carnoba wax and uncoated samples during 12 days shelf life storage. The experimental design was factorial based on completely randomized design with three replications. Limon samples were maintained at ambient temperature of 25 ℃ and relative humidity of 80-85%. Chemical characteristics (pH, citric acid, fruit juice TSS, vitamin C) and mechanical characteristics (weight loss percentage, sphericity coefficient, maximum shear force, maximum fracture force and maximum tensile strength of the fruit skin) were measured during storage.Results and Discussion The results of experiments showed that the trend of changes in vitamin C content decreased during storage. But this decrease was slower in the different percentages of chitosan-clay, olive oil coating and carnoba wax than in the control samples.The results showed the significant differences at 1% and 5% levels between different coatings at maximum fracture force, percent weight loss and pH. In addition, the effect of storage times on TSS, pH and maximum fracture force was significant. The lowest and highest percentage of weight loss for uncoated samples and olive oil coating were 12.3% and 10.23%, respectively. Results showed that the coated fruits had the better performance in preserving the quality of properties than the uncoated samples and 5% chitosan-clay nanocomposite coatings were higher performance than the other coatings.Conclusion In this study, the effect of chitosan-clay nanocomposite, olive oil, Carnoba wax and uncoated samples during 12 days shelf life storage on Chemical characteristics (pH, citric acid, fruit juice TSS, vitamin C) and mechanical characteristics (weight loss percentage, sphericity coefficient, maximum shear force, maximum fracture force and maximum tensile strength of the fruit skin) were investigated. The results of this study showed that 5% chitosan-clay nanocomposite coatings were higher performance than the other coatings.
Volume 45 - Issue 4
Ehsan Ghojehpour; Vahidreza Jalali; Azam Jafari; Majid Mahmoodabadi
Abstract
Introduction Spatial and temporal variations of soil characteristics occur in large and small scales. Investigating the variability of soil parameters is considered as one of the requirements for proper management of fertilizer resources in a sustainable agricultural system. Studying of these variation ...
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Introduction Spatial and temporal variations of soil characteristics occur in large and small scales. Investigating the variability of soil parameters is considered as one of the requirements for proper management of fertilizer resources in a sustainable agricultural system. Studying of these variation is very time-consuming and costly especially in large scales. In order to the fast and reliable determination of the soil properties, various interpolation techniques have been developed and applied. The most widely used interpolation technique is the different Kriging types. The copula function is one of the new interpolation techniques that are recently used in sciences such as hydrology. Thus, the aim of this research was to evaluate the spatial variation of some soil chemical properties using the copula function and comparisons with geostatistics techniques. Materials and Methods Sampling by regular networking was done in an area of 484 ha located in 10 km far from the west of Baft city, located in Kerman province, central Iran (latitude of 29° 15′ N and longitude of 56° 29′ E). In the studied area, three agricultural, pasture and industrial sites are located nearby. The common crops of the region are wheat, barley, alfalfa, legumes and orchards of walnuts, pomegranates, almonds and grapes. The average height of the studied area is 2270 meters above sea level, the average annual temperature of the area is 16 degrees Celsius, and the average annual precipitation of the area is 247 mm. The soil used for the experiment was collected from 0 to 20 cm depth of the field. 121 soil samples were air-dried and, some physical and chemical properties were measured. In order to fit the Copula function to the data, first the appropriate marginal distribution function should be fitted to the data. For this purpose, three tests were used: Kolmogorov-Smirnov, Anderson-Darling and Chi-Square. The mentioned tests were carried out in the EasyFit 5.5 statistical software. By fitting the best marginal distribution function, the cumulative value of the marginal distribution function is calculated for each data. After calculating the above values, detailed functions can be fitted to the data. Finally, the accuracy of each interpolation method was evaluated according to the root mean square Error (RMSE), coefficient of determination (R2), mean absolute error (MAE) and mean biass error (MBE) indices. Results and Discussion In all types of geostatistical methods, the first step in interpolation is to fit the semivaiogram to the measured data, so after normalizing the data and validating the models, the appropriate model was selected for fitting the semivaiogram. Among the measured parameters, Pava and Kava semivaiogram followed spherical model and the interpolation of the above variables was done on the basis of this model. Copula analysis showed that the available phosphorous and potassium variables followed from the Wakeby and gamma distribution function, respectively. Also, based on the Pearson correlation coefficient, the correlation between pairs of points was less than 2000 m and the distance more than 2000 m was known as an independent distance. Based on the validation criteria for Pava parameter, Median copula function, Average copula function, IDW, Ordinary Kriging, Disjunctive Kriging, Universal Kriging and Simple Kriging have better estimates, respectively, and in the same way, the best interpolator for Kava parameter Median copula function, Average copula function, Ordinary Kriging, Universal Kriging, Disjunctive Kriging, Simple Kriging and IDW were determined, respectively. The estimation performance based on the coefficient of determination (R2) showed that value of this coefficient for copula function for available phosphorous and potassium were 5% and 4% greater than conventional geostatistics techniques. Also, the error of estimation was less for copula function indicating the better performance of copula to estimate the mentioned soil propertiesConclusion This study was performed to investigate the Feasibility study of Copula function in predicting some soil nutrients and comprising this method with widely used methods of geostatistics. Our results demonstrated that the copula function method is more capable than the classical geostatistical methods in estimating soil properties due to the non-dependence of this method on the normality of the data distribution and outlier data. Therefore, with the help of this method, having a reliable and high-quality data bank of soil characteristics, acceptable maps of other soil characteristics can be presented at various scales.
Volume 44 - Issue 4
Masud Sadeghi mianrodi; Abdolamir Moezi; Ali Gholami; Teimor Babaei-nejad; Ebrahim Panahpur
Abstract
Introduction Land-use changes may influence various natural and ecological processes, including soil nutrients, soil moisture, soil erosion, land productivity and biodiversity. Compact cropping and lack of suitable management approaches in agricultural fields all over the world have affected soil properties ...
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Introduction Land-use changes may influence various natural and ecological processes, including soil nutrients, soil moisture, soil erosion, land productivity and biodiversity. Compact cropping and lack of suitable management approaches in agricultural fields all over the world have affected soil properties in vast areas and led to changes in soil quality. The cultivation of sugarcane in the south of Iran started 60 years ago. The cultivation of sugarcane was mechanized in the southwest of Iran in the late 1950s. Over the past 40 years, the sugarcane yield has been declined from 110 to 50 tons per hectare over the same period. The long-term cultivation period (6 to 7 months), high water consumption (30,000 cubic meters per hectare at 25 to 30 turns irrigation), extensive heavy machinery uses in the planting stage, and sugarcane harvesting may change soil properties. In order to determine how these changes are taking place, it is necessary to examine the land qualitatively and quantitatively to prevent further destruction of this vast God-given source. Due to the fact that few types of research have so far been conducted on the long-term effects of cultivation on the physical and chemical properties of soil, this study aimed to investigate the effect of long-term sugarcane cultivation on some chemical and physical properties of soil in the Karoun Agro-industry Unit in Shoushtar city, Iran.Materials and Methods This research was carried out to investigate the effect of long-term sugarcane cultivation on soil chemical and physical properties in Karoun Agro-industry Unit in Dimcheh with the geographical coordinates Latitude: 32° 02' 60.00" N Longitude: 48° 50' 59.99" E and 68 meters above mean sea level located at 12 kilometres to the west of Shoushtar city in Khuzestan province of Iran. The total area of the land is 45,000 hectares. This area has warm and dry climate conditions. The dominant soils of the area are classified in the large Calcic Haplousteps group. This study was carried out as a factorial experiment based on a complete randomized design with two factors, including fields in seven levels and depth in three levels (0-30, 30-60 and 60-90 cm) and three replications. Soil samples were collected from three depths in six fields with long-term sugarcane cultivation and adjoining uncultivated land. Then, some chemical properties were measured by standard methods: Soil texture by hydrometric method, soil organic matter content by wet oxidation method, the soil sodium bicarbonate extractable phosphorus by Olsen method and available K using 1 N NH4OAc were measured. Also, total porosity and mean weight diameter were calculated based on conventional equations. Statistical analysis of data was performed by SAS 9.2 software, and the comparison of means was made using Duncan's multidomain test at a 1% probability level. Figures were also drawn using Microsoft Excel software.Results and Discussion Results indicated that land-use changes and long-term sugarcane cultivation result in soil chemical properties changes. By land-use changes, the amount of sand decreased from 22.55% in virgin soil to 6.67% in sugarcane fields. The apparent density and the mean weight diameter by changing the use of virgin soil to sugarcane farms increased by 16% and 67%, respectively, though this result was opposite for the total porosity. Also, land-use changes from virgin soil to sugarcane fields increased organic matter and absorbable phosphorus and reduced potassium absorbable and carbon-to-nitrogen ratio. Overall, changes in chemical properties in surface soil (0-30) were more than other depths (30-60 and 60-90). Also, estimating the correlation coefficients between different traits under the studied treatments showed that sand was correlated with all traits except clay and organic matter. In contrast, the clay had a positive and significant relationship with the mean weight diameter of soil aggregates.Conclusion This research showed that the soil chemical properties of different sugarcane fields significantly changed by the land-use changes of long-term sugarcane cultivation. Thus, the land-use changes, abundant irrigation and leaching increased the organic matter, the mean weight of the diameter of aggregates and the apparent density of the soil. Also, the amount of phosphorus absorbed by sugarcane and fertilization increased, while the amount of organic matter of C/N and soil absorption potassium decreased in cultivated land. Potassium is essential for sugarcane growth, and the reduction of potassium absorbable can cause limitations in its growth and performance. On the other hand, concerns about soil density and change in the optimal plant growth conditions due to heavy agricultural machinery are clear and severe. Therefore, creating a cultivated system with minimal density is essential. Also, soil chemical properties monitoring and maintaining the quality of the studied soils must be considered in land management approaches.Keywords: Land management, land-use changes, Soil quality, sugarcane
Volume 43 - Issue 4
Saleh Sanjari; Mohammad Hady Farpoor; Majid Mahmoodabadi; Saied Barkhori
Abstract
Introduction Soil classification is a process of showing basic differences among soil classes (5). Different soil classification systems are created for soil classification, but Soil Taxonomy and World Reference Base for Soil Resources (WRB) are among the most favoured systems in the world including ...
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Introduction Soil classification is a process of showing basic differences among soil classes (5). Different soil classification systems are created for soil classification, but Soil Taxonomy and World Reference Base for Soil Resources (WRB) are among the most favoured systems in the world including Iran. This system (WRB) is accepted by soil scientists in the world and Soil Taxonomy has also been used in several countries (7). Each of the two mentioned systems has its own strong and/or weak points to show soil characteristics. However, comparing Soil Taxonomy and WRB for calcareous and gypsiferous soils of central Iran, Sarmast et al. (16) reported that according to specifiers used in WRB, this system could be more efficient than Soil Taxonomy. Various environmental conditions and its fluctuations in Kerman Province caused different soils to be formed in the province. Use of soil moisture and temperature regimes by Soil Taxonomy which is totally neglected by WRB system may emphasize that Soil Taxonomy could provide better results for these soils. That is why the present research was performed to compare Soil Taxonomy and WRB systems in the area of the present research with different climates and to show the efficiency of the two systems to describe selected soil characteristics in Kerman Province. Materials and Methods According to climatic variations, four study sites were selected in Kerman Province. Sites 1 (elevation of < 2000 m asl) and 2 (elevation of >2000 m asl) in Baft and Rabor areas were located in the south west of the province. Moreover, sites 3 (around Jiroft and Anbarabad) and 4 (around Roodbar-e-Jonoob and Ghaleganj) were located at the center and south of the province, respectively (Fig. 1). Table 1 shows the soil moisture and temperature regimes of the areas under study (3). Twenty-five pedons on different geomorphic surfaces were described and one representative pedon on each geomorphic surface (total of 11 representative pedons) were selected (Fig 1). Soil description and sampling performed (18) and the collected samples transferred to the laboratory. It is to be noticed that soil moisture regime in site 3 has changed from ustic to aridic during normal years defined in Soil Taxonomy. Ustic/ hypertermic soil moisture/temperature regimes were reported for soils of Jiroft and Anbarabad according to the soil moisture and temperature map of soils of Iran (3). However, according to the latest climatic data (30 years' data and the concept of normal years as defind in Soil Taxonomy, 2014) used in the NSM Software, the soil moisture regime was estimated as weak aridic. Results and Discussion Histic, mollic, argillic, natric, calcic, anhydritic, and cambic horizons were investigated after field work and laboratory analyses. Results of the study show that addition of new Calcixeralfs, Gypsiustalfs, and Gypsicalcids great groups together with newly added Calcic Natrargids, Calcic Natrustalfs, Gypsic Calciustalfs, Typic Petrogypsids, Anhydritic Haplogypsids, and Angydritic Petrogypsids subgroups to the Soil Taxonomy system from one hand, and addition of anhydrite and hypercalcic qualifiers to WRB from the other hand, cause a higher correlation between the two systems. Besides, climatic fluctuations of the recent years in Jiroft and Anbarabad areas caused a change in the soil moisture regime according to normal years defined in Soil Taxonomy. That is why soil name was changed in Soil Taxonomy system. However, WRB system shows no variation because this system is not related to climatic data. Since anhydritic horizon was added to Soil Taxonomy (2014) system, addition of this horizon is recommended to WRB for better correlation of the two systems as was also suggested by Sarmast et al. (16). Meanwhile, soil names in the WRB system provide more information about characteristics of young soil (including yermic qualifier to show desert pavement) compared to Soil Taxonomy.Conclusion Soil classifications showed that WRB system could describe soil characteristics in the area more efficiently compared to Soil Taxonomy. Climate change caused a variation in soil moisture regime of Jiroft and Anbarabad areas according to normal years of Soil Taxonomy system, which in turn changed soil nomenclature in this system. WRB system is not related to climate that is why soil names were not changed in the above mentioned areas. Besides, WRB system is more efficient to classify gypsiferous soils because gypsum content which is an important factor for management of gypsiferous soils is better focused by WRB. However, lack of anhydritic horizon in the WRB system is a weak point, that is why addition of this horizon was suggested by the authors. It is recommended that soil moisture/temperature regimes of study sites be calculated by softwares using climatic data because the climatic variations of the recent years might have changed the soil moisture/temperature regimes reported in the map of 1998 due to the definition of normal years defind in Soil Taxonomy.
Volume 30
V. R. Hamidinia; S. Kamgar; Y. Emam
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 35 - Issue 1
A. Raisizadeh; G.A. Sayyad; M. Khorramian; A. Khademolrasoul
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 36 - Issue 1
Saeid Minaei; Pezhman Nikandish; Barat Ghobadian; Mohammad Sheikh Davoodi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 35-50
Abstract
In mathematical modeling and design of hydraulic systems, it is very important to determine the flow rate through control valves on the basis of discharge coefficient and also the orifice cross section created in the valves. Although the discharge coefficient depends on the oil flow type through the ...
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In mathematical modeling and design of hydraulic systems, it is very important to determine the flow rate through control valves on the basis of discharge coefficient and also the orifice cross section created in the valves. Although the discharge coefficient depends on the oil flow type through the orifice, it is usually assumed as constant in hydraulic valves. Thus, in this paper, the discharge coefficient of orifice created by spool and three conventional poppet types in hydraulic valves were examined experimentally. Then, based on the experimental data, the curve fitting of discharge coefficient versus square root of Reynolds number was extracted for four types of orifice created by the moving members including spool, cone, spherical and cylindrical. Curve assessment showed that the discharge coefficient in turbulent flow for all four types of moving members was constant, but in the laminar flow conditions, the discharge coefficient linearly varied by square root of Reynolds number for them. The discharge coefficient in turbulent flow conditions for the orifice created by spool was lower than the other moving members. While, the slope of the linear part of the discharge coefficient curve for this orifice was more than others.
Volume 37 - Issue 1
R. Sedghi; Y. Abbaspour Gilandeh
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 35-47
Abstract
Good soil structure is important for crop growth. One of the main characteristics of the soil structure, which affects the plant growth and its yield, is soil aggregate size distribution. There are several ways to characterize the stability of soil aggregates such as the mean weight diameter (MWD). Researchers ...
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Good soil structure is important for crop growth. One of the main characteristics of the soil structure, which affects the plant growth and its yield, is soil aggregate size distribution. There are several ways to characterize the stability of soil aggregates such as the mean weight diameter (MWD). Researchers generally use MWD as the most important criterion to express the degree of soil fragmentation of a loamy sand soil. In this study, the effects of soil moisture content at two levels, tractor forward speed at five levels and working depth at five levels were investigated on soil fragmentation for seedbed preparation using a combination of primary and secondary tillage implements of subsoiler, moldboard plow and disk harrow as conventional tillage combination in the region. Field experiments were carried out in the research field of University of Mohaghegh Ardabili based on a completely randomized design (CRD) with three replications. In this paper, an intelligent model based on Mamdani fuzzy model was developed to predict soil fragmentation during tillage practice. The model included 50 laws. Analysis of variance showed that the main effects of travel speed and working depth were significant on the soil fragmentation (at probability level of 1%). By increasing the forward speed, working depth and soil moisture content, MWD of aggregates significantly increased. Moreover, the interactive effect of speed and working depth was significant (at probability level of 1%). Also, using the fuzzy model, the optimum range of the investigated parameters was achieved 12-16% for moisture content of a loamy sand soil, 5.92 km/h for travel speed and 15 cm for working depth.
Volume 35 - Issue 2
Hamid Matinfar; Manouchehr Kalhor; Afshin Shabani; Saleh Arkhi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 37-54
Abstract
The rate of soil erosion and sediment yield estimation in the catchment areas is considered as an important factor for soil and water conservation practices. Due to difficulties and restrictions in common soil erosion methods, applying a high accuracy method with lowest cost and time consuming would ...
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The rate of soil erosion and sediment yield estimation in the catchment areas is considered as an important factor for soil and water conservation practices. Due to difficulties and restrictions in common soil erosion methods, applying a high accuracy method with lowest cost and time consuming would be necessary. Assessment of soil loss in hilly areas with capacity of rang land that has changed to cultivation areas because of high population and evaluation of Cesium 137 method to estimate soil loss constitutes two main purposes of this research. So, the Cesium 137 method was performed to measure soil loss in Raymaleh watershed where land use alteration is common. To do so, soil sampling and measuring soil surface features were done in seventeen transects composed of eleven transects on hilly area (complex slopes with 5-50 percent) and six transects on downhill areas (simple slopes with 2-8 percent) were performed by association with aerial photographs (1:20000) and topography map (1:50000). In addition, for complex slopes (including upper, shoulder, back, foot and top parts) and simple slopes (including upper, middle and lower parts) according to slope length between 2 to 7 soil samples (0-27 cm) the taken and Cesium-137 measured by Spectrometer device. Results showed that the average soil loss in different parts of complex slope including summit, shoulder and back slope respectively was 31.74, 66.28 and 48.77 ton/ha/yr, whereas for simple slopes the losses 78.60, 54.47, 79.54 ton ha-1 yr-1. The rate of sedimentation in non erosion parts such as top slope was 64.27 ton ha-1 yr-1 and for foot slope soil deposition was more dominant than soil loss. Generally, we may conclude that Cesium 137 could be considered as a high accuracy and fast method to estimate soil loss and sedimentation.
Volume 33 - Issue 2
Volume 32 - Issue 1
D. Zarea Haghi; M. Shorafa; M.R. Neyshaboori; G.R. Savaghebi
Volume 34 - Issue 2
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 41-53
Abstract
Nitrogen as one of the main nutrients is important for plant growth and soil fertility. The available soil nitrogen can be changed due to N uptake by plants and microorganisms, leaching, denitrification, and volatilization processes. The application rate of N fertilizers is very important on nitrogen ...
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Nitrogen as one of the main nutrients is important for plant growth and soil fertility. The available soil nitrogen can be changed due to N uptake by plants and microorganisms, leaching, denitrification, and volatilization processes. The application rate of N fertilizers is very important on nitrogen fate in the soil. To study the effects of three different rates of nitrogen fertilizer on nitrate, ammonium, nitrogen mobility through the soil, a split plot in the form of randomized complete block design experiment was conducted with three replications in Agricultural Research Center of Safiabad Dezful. Treatments comprised three nitrogen fertilizer rates including 150, 225 and 300 kg.ha-1. Nitrogen fertilizers were applied in two splits one after planting and the other in 6-8 leaves stages of maize using the fertigation method. Soil samples were taken 8 to 10 days before and after each fertigation from the depths of 0-30, 30-60, 60-90, 90-120 cm. In the soil samples, nitrate and ammonium concentration were measured by distillation of steam water and total N using Kejeldal methods. The results suggested that fertilizer application increased soil nitrate and total nitrogen concentrations through the soil profile. The most concentrations were measured in 300 kgN.ha-1 treatment. Nitrat movement to lower layers of soil was restricted due to soil heavy texture, high bulk density and optimized irrigation. The most nitrate concentration was observed in 0-30 cm layer of soil. Ammonium concentration was not influenced by the rate of fertilizer and its variation along soil profile was irregular.
Volume 42 - Issue 4
E. Shirmohammadi; H.A. Alikhani; A.A. Pourbabaee; H. Etesami
Abstract
Introduction The use of invitro hydroponic culture is one of the useful and practical methods for selection of superior isolates of plant growth promoting rhizobacteria with high colonization potential at root surface. In this regard, the present study was designed to select superior isolates isolated ...
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Introduction The use of invitro hydroponic culture is one of the useful and practical methods for selection of superior isolates of plant growth promoting rhizobacteria with high colonization potential at root surface. In this regard, the present study was designed to select superior isolates isolated from dry-land farming of Qazvin and Zanjan provinces during the previous stages of this investigation. Materials and Methods This experiment was carried out based on a completely randomized design (CRD), including: inoculation of wheat seeds with 16 bacterial isolates and culture of seedlings in Hoagland nutrient solution (EC 8 dS/m and osmotic potential (OP) -0.54 MPa) containing tricalcium phosphate (source of low-soluble phosphorus), as well as non-inoculated seedlings was cultured in Hoagland nutrient solutions containing monopotassium phosphate (control with source of soluble phosphorus) and tricalcium phosphate (control with source of low-soluble phosphorus) at three replications in growth chamber for 45 days. The length of the light (with 196 μmol photons m−2 s-1 light intensity) and dark period in these times was 16 and 8 h, respectively, The day and night temperature were 25±2 and 20±2 °C, respectively. At end of experiment (45 days after transportation of seedlings into invitro hydroponic culture) shoots and roots of plants were harvested separately; then, Population of phosphate solubilizing bacteria (PSB) on root surface, pH and concentration of available phosphorus in nutrient solution, fresh weight, dry weight and length of both section of plants, P-concentration and P-uptake of plant, and relative water content (RWC) of leaf were measured. Ultimately, correlation (Pearson) among measured traits were calculated. Results and Discussion Results showed that inoculated wheat seedlings with B18 isolate perished. It seems that B18 isolate was either a highly pathogenic plant or its metabolites were highly inhibitory to the seedling which in short time killed the wheat seedling. Except B (14, 17, and 32) isolates; the rest of isolates had over 6×106 CFU/g root fresh weight. All bacterial isolates compared to the control with source of insoluble phosphorus, increased available phosphorus and decreased pH of nutrient solution. Dissolution of inorganic phosphates by PSB with chelating processes, secretion of inorganic and organic acids has been proven topic. Thus, reducing pH and increasing soluble phosphorus in nutrient solution at PSB treatments are reasonable. B (1, 2, 3, 4, 5, 6, 14, 17, 32) isolates treatments compared to control with tricalcium phosphate, increased RWC of leaf, and also increased length, fresh weight and dry weight of root and shoot of wheat plants. Previous research has shown that inoculation of plants with PGPR under drought and salinity conditions improved RWC of plant leaves and plant growth indices; Of course, result of some experiment show that some of PGPR do not always improve plant growth under all conditions. There was a significant positive correlation among P-uptake, RWC, root length, shoot height, fresh and dry weight of root and shoot of wheat plant. Also, the pH of nutrient solution had a positive correlation with root length, but it had a negative and significant correlation with P-concentration of nutrient solution and P-concentration of plant. PSB population at root surface had a negative correlation with pH of nutrient solution and root length of plant, but with P-concentration of nutrient solution had positive and significant correlation. Conclusion All of screened and selected PSB isolates in lab (in respect of PGP traits) could not promote plant growth; even some of these isolates (such as B15 and B18) had negative effects on wheat growth indices. Inoculation of wheat with PSB isolates significantly increased the use of insoluble phosphorus. Solubility of tricalcium phosphate by isolates and increased phosphorus availability cannot lonely improve wheat growth indices; it seems that the outcome of the set of PGP effects of these bacteria and the secretion of their metabolites in the presence of plant root are determinative agents for improvement of wheat growth indices. Generally, B (1, 2, 3, 4, 5, 6, and 32) isolates were superior isolates in respect of colonization at root surface, relative water content (RWC) and growth indices of wheat plant; and these isolates are recommended for further experiments in greenhouse and field (in order to production of suitable biofertilizer for dry-land farming of wheat).
Volume 33 - Issue 1
Volume 34 - Issue 1
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 43-55
Abstract
The current study was conducted to compare the effect of different tillage methods on wheat yield of canola-wheat rotation in dryland areas during three years (2005-2008) north of Khouzestan (Baghmalek city). Randomized block design with five treatments was applied by using four replications. Canola ...
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The current study was conducted to compare the effect of different tillage methods on wheat yield of canola-wheat rotation in dryland areas during three years (2005-2008) north of Khouzestan (Baghmalek city). Randomized block design with five treatments was applied by using four replications. Canola tillage was done with conventional method and the experimental wheat treatments were: (1) moldboard plow + grain-drill, (2) chisel plow + grain-drill, (3) moldboard plow with removed moldboard + grain-drill, (4) sweep plow + grain-drill and (5) no-till-drill. The investigated indices were percent age of organic materials, soil moisture content (W.B), wheat yield and other agronomical factors. Complex variance analyses of the three years data showed no significant difference between tillage methods and interaction of tillage methods with year in case of soil moisture content in different plant growth stages. However, the effect of years was different for this factor. Analyses of variance for different tillage methods showed that there was no significant difference between percent age of organic materials in soil depths. The complex variance analyses of data also showed that tillage methods had a significant effect on harvesting index and biological yield but the difference in grain yield and other agronomical factors was not significant. In general, the tillage methods did not affect wheat yield. Hence, the conservation methods are recommended for this condition. Regarding the harvest index, the sweep plow with 43 percent had the highest and no-till-drill with 36 percent had the lowest amount. Moreover, in biological yield, the moldboard plow with 5263 and sweep plow with 3718 kg/ha had the most and the least values respectively.
Volume 38 - Issue 1
H Zaki Dizaji; S Minaei; T Tavakoli Hashtjin; M Mokhtari Dizaji
Abstract
Introduction: It is known for a long time that ultrasound offers unique features in food industry and also agricultural industry for characterizing products in their intact state, with no sample preparation and no sample destruction. However, it is used still mostly in research environment and there ...
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Introduction: It is known for a long time that ultrasound offers unique features in food industry and also agricultural industry for characterizing products in their intact state, with no sample preparation and no sample destruction. However, it is used still mostly in research environment and there is little available research about fruit quality assessment by ultrasonic technique in IRAN. Knowing the quality of agricultural products not only from the perspective of export and domestic consumers is important interests, but it also helps to control and reduce its postharvest losses. Determination of the quality of agricultural products such as fruits and vegetables is important in commercially competitive modern agriculture. Physiological degradation of pomegranate results in reduced quality exhibited as peel softening and loss of freshness. Native land of the pomegranate (Punica granantum L) is IRAN and it is an important tree of the tropical and subtropical regions of the world which is valued for its delicious edible fruit. Among the native fruits grown for export, pomegranate has a special significance. According to the FAO statistical report, Iran is the first producer and exporter of pomegranate in the world. Despite its importance, its basic tissue attributes and whole fruit maturity has not been studied. On the other hand, pomegranate fruits are not maturity indicators obviously such as tomato. For this reason pomegranate was selected for the current research. In this study, ultrasonic technique is utilized as a suitable method for quality determination of pomegranate fruit. Materials and Methods: Ultrasonic technique is one of the earliest nondestructive testing (NDT) methods, which is still under development for quality determination of agricultural products. In this research, pomegranate quality was evaluated using Ultrasonic technique and punch test (Magness-Taylor). In line with previous research work, a novel ultrasonic system dubbed “Ultrasonic Qualimeter System” (UQS) and its control programs, “Ultrasonic Qualimeter System software“(UQSS) with central frequency 40 kHz were utilized to evaluate ultrasonic indices of pomegranate fruit in four quality classes of unripe(hard), ripe(medium), overripe(soft) and decayed(so soft). This ultrasonic system works based on processing the signal passing through the materials. The ordinary indices of the through-transmission ultrasonic test are wave velocity and attenuation coefficient. The other ultrasonic index is root mean square that is calculated in time zone of the digital signals. Firmness as a mechanical property, and ultrasonic wave velocity as an ultrasonic parameter, was selected to assess pomegranate quality. Evaluation of pomegranate quality was carried out through testing of its tissue and peel. The firmness index of pomegranate peels was metered by the punch test using universal material test machine (Hounsfield, H50 K-S, England). Results and Discussion: UQS were successful in transmitting ultrasound wave through pomegranate tissue (1-2 cm thickness) and peel, but results of excited and received signal processing showed that due to its non-homogenous tissue pomegranate vigorously diminished the intensity of transmitted waves. By comparison, the attenuation coefficient of pomegranate peel and its tissue is higher than that of the other agricultural products such as potato and avocado. Statistical analysis demonstrated that the quality of pomegranate fruit can be assessed using ultrasonic technique, so that decreasing freshness of pomegranate peel samples leads to decrease of wave velocity from 290 (unripe fruit) to 63 m/s (decayed fruit). In other words, depending on samples quality levels, transmitted wave velocity is varied about 230 m/s for pomegranate peel samples. One of the mechanical properties that are most useful to demonstrate fruit quality conditions is stiffness. Initially, analyses showed that Chart trend of stiffness in four quality levels is similar to wave velocity. So non-linear regression models were developed with good correlation (R2=0.83) between the firmness and ultrasonic velocity. Results of regression analysis demonstrated that ultrasonic indices of pomegranate peels can be used for inspection of pomegranate quality conditions. Conclusion: The first step in nondestructive assessment of any medium is introducing fitness index or indexes in which it can show the medium conditions. In this research, statistical analysis demonstrated that the quality of pomegranate fruit can be assessed by ultrasonic technique. However, it is necessary to carry out more research to improve this technique for widespread applications. To use this method, the ultrasonic system should be modified so that the transmitted and received transducers test the whole pomegranate by its peels.
Volume 41 - Issue 3
Post Harvesting Technology
Mohammad Momeni Arani; Abbas Rezaei Asl; Azim Ghasemnezhad
Abstract
Introduction Drying is one of the important stages after harvesting of plants and agricultural products, which plays an important role in the quantity and quality of the active ingredients. The purpose of drying is to reduce water to a certain level for low and stop the microbial activity. Therefore, ...
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Introduction Drying is one of the important stages after harvesting of plants and agricultural products, which plays an important role in the quantity and quality of the active ingredients. The purpose of drying is to reduce water to a certain level for low and stop the microbial activity. Therefore, in laboratories the effects of different levels of temperature and time are investigated on different plant properties during drying operations with laboratory dryers and ovens. It can be said that the principled and thorough drying of medicinal plants is necessary in order to reduce moisture, increase the shelf-life and increase the quantity and quality of the active ingredients. Today, many control algorithms are used to control temperature, which is much more efficient than the on-off. Fuzzy control is suitable for fast control and high accuracy of proper nonlinear processes. Likewise, the type of ventilation and the placement of thermal elements are also very influential on the heating system and the temperature of the chamber. Today as foreign companies, in addition to focusing on the type of control system and intelligence ovens, many studies have been done on how the element is placed, on its type, the shape of the fan, its type, and the design of the air channels. Materials and Methods The dryer was designed with software Solid Works and constructed in manufacturing workshop of the Bio-System Mechanics Engineering Department of the Natural Resources and the Agricultural Sciences University of Gorgan, Iran. The device has a fuzzy control system, a ventilation, and fan system. The built-in dryer has two mechanical and electrical parts. This dryer has an external chamber with dimensions of 74 × 50 × 60 cm and internal chamber dimensions of 40 × 35 × 50 cm. The device was insulated with thermal spray foam. The electronic circuit was designed using Proteus simulation software and implemented on the board. The main piece of information processing and controlling the algorithm in the dryer control system is the microcontroller. The microcontroller programming was written by C software and transmitted to the microcontroller with the Code Vision software. The tests were performed at three levels of 60, 80, 90 °C. The programmability of the device was also evaluated simultaneously for four different temperatures and times. The device was evaluated at 4 levels of 90, 70, 50 and 30 °C and four levels of the time were done respectively 10, 10, 10, and 20 min. Also, in the process of increasing temperature, the temperatures of 40, 60, 80 and 90 °C respectively were tested. Also, the stability function and the time to reach the temperature were compared with two samples of the laboratory dryer (oven) imported Memmert and Bender models which had a fuzzy control system and a ventilation system and a built-in oven model in the interior. Results and Discussion Because exactly as wasted, the temperature of the chamber walls is applied to the chamber, the device is capable of maintaining the temperature of the chamber at the set point. The result of the evaluation in the energy waste from the wall of the device showed that after about 200 min, the temperature of the internal chamber (which was at 80 ° C) was equal to the outside temperature of the chamber. The results showed that during temperature stability, the difference in temperature between different points of the compartment (places where laboratory samples are placed) is less than ±0.5. The programmability of the device was evaluated at 4 levels of 90, 70, 50 and 30 °C; after reaching the temperature of 90 °C, and at the end of the scheduled time, the temperature is reduced to a minimum, reaching the next temperature. Reducing the temperature for other temperatures was also done according to the program. The results of the programmability of the device were shown in the incremental step of the temperature; in the incremental process, as the temperature decreases, the temperature difference between the points is very small and reaches the temperature stability as soon as it reaches the regulated temperature. The control system used can properly maintain the temperature in a stable state. The results of the comparison of the performance of the dryer control system made with other experimental dryers at a temperature of 80 ° C showed that the dryer was able to stabilize the inside of the compartment at the desired point, in comparison with other ovens. The built-in dryer function is compatible with the Memmert UFE500 and the Binder FE53 ovens. Due to the cost of the device, its use will be very useful for conducting research in research centers. Conclusion The fuzzy control system used in the dryer was able to properly control the temperature of the chamber according to the program. The control system of the device was able to control the temperature of the chamber at a regulated point with a minimum temperature variation (less than half a °C). The built-in dryer was able to reduce and increase the temperature step by step in a given temperature range according to the given program. The performance of the dryer, compared with other ovens, showed that it could match the best of imported ovens.
Volume 39 - Issue 2
Soil, Water and Plant Relationships
F Kamyab Talesh; B Mostafazadeh Fard; M Vazifedoust; M Navabian; Shayannejad M
Volume 41 - Issue 1
Plant Nutrition, Soil Fertility and Fertilizers
Majid Hejazi
Abstract
Zinc (Zn), an essential micronutrient for both plants and humans, is involved in a number of physiological and biochemical processes. Calcareous soils cover more than 30% of the earth’s land and are characterized by the high pH and low availability of plant nutrients. Zinc (Zn) that is freely available ...
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Zinc (Zn), an essential micronutrient for both plants and humans, is involved in a number of physiological and biochemical processes. Calcareous soils cover more than 30% of the earth’s land and are characterized by the high pH and low availability of plant nutrients. Zinc (Zn) that is freely available in acid soils is only sparingly available in calcareous soils, due to their poor solubility at high pH. Zinc deficiency in most of the world’s soils has resulted in significant loss of agricultural yields. Information about Zn availability in soils is very important in the view point of Zn nutritional status of plant and human. Several soil physicochemical properties including organic matter, CaCO3, pH, moisture and total Zn concentration affect soil Zn availability to plants. Under Zn deficiency, plants tend to release organic acid in the rhizosphere which in turn increases soil Zn availability. Oxalic acid is the simplest dicarboxylic acid with two pKa values, 1.23 and 4.19 and it occurs in sediments, forest soils, and agricultural soils, especially in the rhizosphere. Oxalic acid is able to chelate with the poorly soluble nutrients in the soil and consequently influence their bioavailability. It is known that Zn availability is controlled by adsorption, release, precipitation and dissolution reactions. Study of kinetic models is a useful method to describe the changes in the nutrient availability with time. A knowledge of desorption kinetics may provide important information concerning the nature of reaction and the rate of Zn supply to plants via soil solution. Materials and methods Composite samples of the two soils were collected from 0-30 cm depth of agricultural areas in Kerman province, Eastern Iran. The samples were air dried, crushed and passed through a 2mm sieve. Some soil chemical and physical properties of soil sample including Particle size distribution, Electrical conductivity and pH, Organic carbon, carbonate calcium equivalent, cation exchange capacity, available Zn and Total content of Zn were done according to standard procedures. For the kinetic study, soil samples were weighed (1.5g), placed in a 20 mL centrifuge tube and then 15 mL of oxalic acid with two concentrations of 1.1 and 2.2 mµ L-1 was added. The tubes were shaken from 1 to 72h at 25±2°C. Two drops of toluene were added to each tube to inhibit microbial activity. After shaking, the solutions were centrifuged and filtered through Whatman filter paper No. 42. Zinc concentration was determined in the filtrate using a Vario atomic absorption spectrometer. Several kinetic equations including zero-, first-, second- and third order, parabolic diffusion, Power function and simple elovich were also fitted to experimental data. Results and discussion Zn release by oxalic acid increased with time and the amount of Zn release differed between soils. The difference in the amount of Zn release may be attributed to differences in (i) the total amount of labile Zn which sorbed in the soil; (ii) types, quantities and relative proportions of the soil components by which the Zn is retained and (iii) other soil properties such pH and CEC. The release pattern of Zn included an initial fast reaction followed by a slow reaction that continued up to 72 h. The two phases of Zn release can be due to the heterogeneity of adsorption site with different adsorption affinities. The release kinetic of Zn in soils was poorly described by first- and second-order equations while Time dependent Zn release was best modeled by the simple Elovich, power function and parabolic diffusion equations. Based on the relatively higher values of r2 and the lower values of S.E., the simple Elovich showed the best fitness on the cumulative release of Zn. At each specified time, the lower dose of oxalic acid released Zn from soil more than the higher dose. Organic acids may increase the sorption of metal ions on soil particles through electrostatic interactions, ternary metal–ligand–surface complex formation or surface precipitation. It seems that Zn may interact with oxalic acid where adsorbed to solid phases and resulted in decreased Zn release. The rate parameters derived from the best-fitted model were used to compare Zn release by different concentrations of oxalic acid. The results showed that the rate parameters “ab”, Kp and β decreased with the oxalic acid concentration. Conclusion From the present study, oxalic acid, especially at the lower rate, can increase Zn release and its bioavailability in calcareous soils.
Volume 37 - Issue 2
Y. Ghasemi; M.H. Kianmehr; M. Mohseni Monfared; B. Azadegan; J. Massah
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 47-57
Abstract
Today the chemical fertilizers are replaced with organic fertilizers due to the bad effects on human health and agricultural soils. There are barriers against useful utilization of organic fertilizers such as transportation (high volume), high moisture content, uneven distribution of fertilizers, dust ...
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Today the chemical fertilizers are replaced with organic fertilizers due to the bad effects on human health and agricultural soils. There are barriers against useful utilization of organic fertilizers such as transportation (high volume), high moisture content, uneven distribution of fertilizers, dust production and storage. One of the solutions is densification of manure as pellet or granule. The effects of process parameters were evaluated in laboratory scale rotating drum. The effects of parameters such as drum rotational speed, granulation time, filling percentage of drum and percentage of molasses were investigated on the fracture force of granules. The results showed that all parameters and also interaction of drum rotational speed and granulation time have significant effect on the fracture force. Also, the results showed that with enhancement of granulation time, percentage of drum filling and percentage of molasses, resistance to failure of the granules increased.
Volume 40 - Issue 2
Soil Genesis and Classification
Maryam Mohammadzadeh Mohammadabad; F. Khormali; Farshad Kiani; mohammad ajami
Abstract
Introduction Soil degradation is a widespread environmental problem that occurs as a result of land use change and destruction of vegetation cover that may lead to changes in soil structure and porosity. Land use change and land management have significant effects on physical and chemical properties ...
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Introduction Soil degradation is a widespread environmental problem that occurs as a result of land use change and destruction of vegetation cover that may lead to changes in soil structure and porosity. Land use change and land management have significant effects on physical and chemical properties and biological capabilities of soil. The investigating of undisturbed and natural soil structure using microscopic and ultramicroscopic techniques provides invaluable information about the physicochemical, mineralogical, morphological properties and soil genesis and calcification. Image analysis is an advanced method for quantifying soil properties and increasing the precision of morphological and micromorphological studies. Materials and Methods In this study, in order to investigate the impact of different land uses on porous and microstructure of surface soil horizons, 9 profiles in different land uses, including natural forests, artificial forest, abandoned land, orchard and cropland were extracted and described. Then one sample was taken from each horizon for physical and chemical analysis as well as a few undisturbed samples for micromorphological studies. Physical and chemical parameters such as texture, bulk density (BD), calcium carbonate equivalent (CCE), organic carbon (OC) and mean weight diameter (MWD) were measured. After preparation of thin sections of soil, micromorphological studies were conducted by polarizing microscope. Then from each thin section, 20 photos were taken randomly in plane polarized light (PPL) and cross polarized light (XPL) and transferred to image tool software. The percentage of total porosity of soil, feret diameter and area pores parameters were studied quantitatively. Three classes of feret diameter in micrometer and five classes of area in square micrometers were considered for pores in the soil thin sections. After importing photos to the software and performing calibration, grayscale and subtracting two images, the range of pores was identified by the software. Then in the classification section of software, the highest level of classes in each part was determined and the percentage of pores in each class was calculated and data obtained were analyzed by SPSS 16.0 software. Results and Discussion Micromorphological observations showed that in natural and artificial forests, a significant amount of organic matter in the soil has resulted in the formation of granular and subangular blocky dominant microstructure. While in cropland land use the type of microstructure is mainly massive and angular blocky, due to deforestation and agricultural practices, which resulted in the degradation of soil microstructure. Appropriate environmental conditions and dense vegetation in natural and artificial forests land use lead to significant biological features in comparison to other land uses that were subjected to deforestation. In natural and artificial forests land uses, the percentage of channel and large vughs pores is more than other land uses mentioned above. Tillage results in degradation of soil structure in cropland land use, the majority of pores observed in thin section are vugh and plane. Also, the results of image analysis showed that in natural forests and orchard land uses, pores with diameters ranging from 2 to greater than 10 micrometer and areas ranging from 500 to greater than 1000 square micrometers had the highest frequency in terms of percentage of soil pores. Hence, these soils are considered as quite porous class, while in cropland land use, tillage results in the degradation of large pores showed that pores with diameters less than 2 to 10 micrometers and areas smaller than 5 to 50 square micrometers comprised and the highest percentage of soil pores. Conclusion Asignificant amount of organic matter and low bulk density, and the highest percentage of total porosity are found in natural forest and orchard land uses, while deforestation and cultivation in cropland land use has led to compression and destruction of soil structure. This fact reflects itself in the increased bulk density and decreased total porosity. Agricultural practice has a significant effect on destruction of surface soil structure. Microstructure and voids of cropland land use are mainly massive and angular blocky and plane and vughs, respectively. With changes of land use from forest to cropland, and consequently incorrect land management causes decrease in organic matter. Shortage of organic matter causes decreasing biological activity in surface soils. The best way to prevent degradation of the soil in this area is to preserve natural forests and change cropland land use to orchard and artificial forest land uses.
Volume 42 - Issue 1
Plant Nutrition, Soil Fertility and Fertilizers
Azam Razavi Nasab; Amir Fotovat; alireza astaraie; ahmad tajabadipour
Abstract
Introduction Pistachio is one of the most economical cash crops in Iran that is located in arid and semi-arid regions with low soil organic matter and very harmful ions. The enhancement of the organic matter in sufficient quantity and quality plays an important role in agricultural production and soil ...
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Introduction Pistachio is one of the most economical cash crops in Iran that is located in arid and semi-arid regions with low soil organic matter and very harmful ions. The enhancement of the organic matter in sufficient quantity and quality plays an important role in agricultural production and soil sustainable management. The application of organic matter promotes physical, chemical, and microbial soil conditions, such as soil aggregate stability, water holding capacity, productivity, and fertility which are essential, particularly in the arid and semi-arid regions of Iran. Municipal solid waste compost (MSWC) and cow manure are two cheap, available, and effective organic materials that can be used in pistachio orchards to improve soil condition and better root growth and more effective nutrient uptake. Gypsum is a chemical material that can replace Ca with Na, especially in saline and sodic soil and cause Na leaching from the soil profile. Sulfur oxidation and gypsum produce acid in the soil and lead to the reduction in pH and the amending of the soil condition. The present study investigated the effects of two organic matters (MSWC and cow manure), two chemical matters (gypsum and sulfur) on some nutrient concentrations in different soil depths (0-20, 20-40, and 40-60 cm depths) and the leaf of pistachio seedlings at the field condition. Materials and Methods A field experiment in a randomized complete block design (split-plot) with three replications was conducted for two years in Izadyaran Company (30 km south of Sirjan, Kerman Province, Iran with hot and dry climates). Treatments were two organic wastes (MSWC and cow manure, 15 Mg ha-1 as the major factor, two chemical amendments (gypsum and sulfur, 10 Mg ha-1) as subplot factor, and soil depths (0-20, 20-40, and 40-60 cm) as the sub-subplot. The organic and chemical matter were poured into the pit of planting and mixed well with soil and a one-year-pistachio seedling was planted (February 2012). In the middle of the summer (August 2013) and at the end of winter (February 2014), plant leaves and soil sampling were done respectively and macro elements’ (Na, K, Ca, Mg, N, and P) concentrations were measured and then statically analyzed with SAS software. Results and Discussion MSWC and sulfurs cause the increase of available K in 40-60 cm depth, because of more mobility of K in comparison to other ions. MSW contains K and sulfur through the reduction in pH that leads to MSW decomposing and increases the available K. Sulfur application rises Ca of soil solution more than gypsum because of common ion effect. MSWC and gypsum also enhanced Mg of the soil solution in 20-40 cm depth. Not only MSWC contained Mg but also SO42- solved some parts of solid MgCO3 and increased Mg in soil solution. On the other hand, mineralization of cow manure increased the available P in 20-40 cm depth. None of the treatments were significant on the concentration of soil Na and N. Probably Na was leaching in primary irrigation and mineralized N was quickly absorbed by the plant. Results of this experiment showed that treatments were not significant on the concentration of Na, K, and Mg of pistachio leaves. The application of cow manure increased Ca and P, and cow manure and sulfur increased the N concentration of leaves. The enhanced concentration of elements may be attributed to the increased nutrient levels in cow manure. Sulfur because of sulfuric acid production in soil solution, declined soil pH and led to more nutrient uptake. This phenomenon continuously provides available nutrients in usable form to the plants. These results may be illustrated by the postulated slow release and contiguous storage of nutrients from organic wastes, such as MSWC and cow manure that increased soil nutrient content after a year. Gypsum, with replacing Na with Ca, decreased harmful ions, such as Na and both gypsum and sulfur and because of sulfuric acid production in soil solution, declined soil pH and then led to soil reclamation and more nutrient uptake. The interaction effect of organic and chemical matters’ treatments ,in the same way, can increase some essential nutrients in the soil and plant significantly because of the synergic effect of the organic and chemical soil reclamation. Conclusion Results of this study illustrated that it is possible to improve the fertility of saline-sodic soils and plant nutrition with cheap and available organic and chemical materials, such as cow manure and MSWC, gypsum, and sulfur. However, due to the difference in mobility of ions, their concentrations vary in different depths, but with the proper planning, the essential elements can be reached to plants at the right time, especially for a strategic plant like pistachio.
Volume 36 - Issue 2
Fatemeh Afsharnia; Mohammad Asoodar; Abbas Abdeshahi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 49-58
Abstract
Effective operation of a system is related to acceptable programming of repair and service activities. Efficient managerial programming is associated with accurate estimation of maintenance system parameters. In this study, four tractors failure rate was investigated by completing 300 questionnaires ...
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Effective operation of a system is related to acceptable programming of repair and service activities. Efficient managerial programming is associated with accurate estimation of maintenance system parameters. In this study, four tractors failure rate was investigated by completing 300 questionnaires from tractor operators in Khuzestan Province. The operators were interviewed in four regions of the province. Under study variables included driver experience, level of education, driving license, skill training course, work location (region and city), type of service and maintenance, storage conditions, distance to first workshop, distance from shelter to farm, machine age, annual use hours and number of failure. Regression analysis by estimating an exponential function showed that the variables such as age of tractor, annual hours used and type of service and maintenance affected the failure rate of each four type tractors. For one percent increase in age of tractor and annual use hours, failure rate increased about 0.6% and 0.24%, respectively. Also, failure rate in MF285, MF399 and U650 tractors was about 0.383, 0.453 and 0.143 percent more than JD3140 tractor, respectively. The preventive maintenance causes 0.252 percent decrease in failure rate.
Volume 41 - Issue 4
Soil Chemistry and Pollution
Samira Alvani; ُSaeid Hojati; Ahmad Landi
Abstract
Introduction Pollution of the environment to heavy metals is one of the major problems of today's world. Following the development of industries, as well as increasing agriculture in response to the growing population, the overuse of chemical fertilizers, mining activities, the production and disposal ...
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Introduction Pollution of the environment to heavy metals is one of the major problems of today's world. Following the development of industries, as well as increasing agriculture in response to the growing population, the overuse of chemical fertilizers, mining activities, the production and disposal of waste waters and sewage sludge, etc., the entry and accumulation of heavy metals in the environment has increased. There are several methods for removing heavy metals from wastewaters. Among the common methods for removal of heavy metals, adsorption, in particular using inexpensive natural adsorbents, due to the ease of implementation and high efficiency is a cost-effective and economical technique. Palygorskite is a fibrous mineral common in clay fractions of soils of arid and semi-arid regions of the world. Although there are several studies applying palygorskite as a suitable mineral for cleaning of wastewaters, however, few studies have been carried out to evaluate the ability of nanosized particles of such clay minerals for removal of heavy metals from the environment. Therefore, this study was conducted to measure the ability of palygorskite nano- and micro-sized particles to adsorb lead and copper from aqueous solutions. Materials and Methods: Kinetic experiments were carried out at 11 different contact times (5, 10, 20, 30, 60, 120, 240, 480, 720, 1440, and 2880 min) using solutions containing 150 mg / l of lead and copper elements at pH=5. Palygorskite used in this study was purchased from Tulsa Co., Spain Then, micron (Results and Discussion The results illustrated that in the so-called samples as nanosized palygorskite, about 50% of the particles in the sample was found smaller than 100 nm in size, and in this case no samples of particle size of 100 nm and smaller were observed in those so-called palygorskite microparticles. The results indicated that by increasing the contact time and reducing the mineral particle sizes from micron to nanoscale, more amounts of lead and copper heavy elements adsorbed onto the mineral. This is due to an increase in the exposure of active sites on the adsorbent surfaces by the pollutant. When the data were fitted with the pseudo first order, pseudo second order and intraparticle diffusion kinetic models, it was revealed that the pseudo second-order kinetic model with a determination coefficient (R2) of 0.99 was the best model describing kinetics of study. Besides, the lower values of the chi-square (ᵡ2) in fit with the pseudo-second-order kinetic model as compared to those in the pseudo first-order model show a greater similarity between the pseudo-second-order kinetic model and the experimental data. The isotherm of Pb and Cu adsorption was also studied using Langmuir and Freundlich adsorption models. It was observed that the data had a better coordination with the Langmuir model with a determination coefficient of 0.99. By increasing the initial concentration of the lead and copper in the solution, their distribution coefficient (Kd) decreases. This suggests that although with increasing initial concentration of lead and copper, their adsorption increased by palygorskite mineral, however, by increasing the initial concentration of heavy metals, the remaining concentration of these elements also increased. The results also illustrated that both micro- and nanoparticles of palygorskite show more affinity to adsorb lean than copper from solutions. Conclusion: In general, it can be concluded from this study that adsorption of lead and copper by palygorskite nanoparticles depends on the contact time and the adsorbent size. Besides, the use of this mineral could be considered as a suitable, feasible and environmentally friendly way to remove lead and copper from aqueous solutions.
Volume 42 - Issue 3
M. Hejazi-Mehrizi; A. Saadatfar
Abstract
Introduction Salinity is one of the common stresses in agricultural lands of arid and semi-arid regions in Iran. Furthermore, excessive CaCO3, high pH, nutritional disorders have been known as limited factors for plant growth and productivity in such soils. The cultivation of salt tolerant plants such ...
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Introduction Salinity is one of the common stresses in agricultural lands of arid and semi-arid regions in Iran. Furthermore, excessive CaCO3, high pH, nutritional disorders have been known as limited factors for plant growth and productivity in such soils. The cultivation of salt tolerant plants such as rosemary (Rosmarinus officinalis L.) is important from the point of view land reclamation. Rosemary is a woody plant, evergreen, perennial herb belonging to Lamiaceae family. It is native to Mediterranean but it can tolerate undesirable conditions such as drought and salinity stresses. Zinc (Zn) and copper (Cu) are essential micro-nutrients that play important roles in plant metabolic processes and can increase plant tolerance to salinity. Zn is vital for protein synthesis, protein stability, and different enzyme activities such as Zn/Cu superoxide dismutase and carbonic anhydrase. On the other hand, chlorophyll production, photosynthesis and enzyme activities are the most important role of Cu in plants. Superoxide dismutases (SOD) are metalloproteins that catalyze superoxide radicals (O2-) produced under salinity stress into oxygen molecules and hydrogen peroxide, resulting to increased tolerance of plants to salinity. The most abundant superoxide dismutase isozyme in plants is Cu / Zn SOD, in which the role of Zn is structural and copper plays a catalytic role. Materials and Methods There is limited information about the effect of micronutrient application on the growth and salinity tolerance of rosemary. This study was conducted to investigate the effect of Zn and Cu co-application on some physiological and biochemical characteristics of rosemary under saline condition. For this purpose, a completely randomized design was carried out in a factorial experiment. The factors consisted of four types of fertilizer treatments (T1: control, T2: control + zinc, T3: control + copper and T4: control + copper + zinc) and three levels of salinity stress (S0: 0, S1: 60 and S2: 120 mM as NaCl) in four replications in a calcareous soil under greenhouse conditions. After 90 days, the plants were harvested and some growth characteristics including shoot and root fresh and dry weight were measured. Some physiological and biochemical properties such as leaf relative water content (LRWC), membrane permeability (MP), malondialdehyde (MDA), shoot and root Na concentration, and shoot and root K concentration were also measured. Results and Discussion The results showed that salinity had no significant effect on fresh weight of shoots, while shoot dry weight of rosemary decreased as 60% in control treatment, 44% in zinc treatment, 38% in copper treatment and 27% in zinc + copper treatment. Leaf relative water contents of rosemary decreased in response to salinity stress, and the only co application of zinc and copper under 120 mM NaCl stress resulted to a significant increase of LRWC (9%). Salinity stress increased the membrane permeability of rosemary leaves. In contrast, at all salinity treatments, addition of Zn and Cu caused a significant decrease in membrane permeability of rosemary leaves. However, there was no significant difference between fertilizer treatments. Salinity stress induced a significant increase in the malondialdehyde content of rosemary. For example, MDA content increased by 39% in control and by 24% in Cu treated plants when salinity level reached from 0 to 120 mmol L-1. Based on the results, in soil treated with 60 mmol L-1, addition of Zn and Cu and at the higher salinity level (120 mmol L-1) addition of Zn to soils had a significant effect on leaf and root Na concentration and thereby improvement of plant salt tolerance. Also, the result showed that co-application of Zn and Cu could reduce the undesirable effect of salinity on shoot and root K concentration and thereby improving plant tolerance to salinity stress. Conclusion In conclusion, zinc and copper, especially in combination form, increases the tolerance of rosemary to salinity by reducing of cell membrane damage, malondialdehyde content, shoot and root plant Na concentration and increasing of LRWC and shoot and root K concentration.
Volume 43 - Issue 1
Javad Khanifar; Ataallah Khademalrasoul; Hadi Amerikhah
Abstract
IntroductionIn recent decades, the potential of soil erosion as serious threat against sustainable land management (SLM) and soil sustainability has been recognized. Furthermore, human-induced soil erosion lead to harmful environmental effects and transportation of sediment to water bodies is accompanied ...
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IntroductionIn recent decades, the potential of soil erosion as serious threat against sustainable land management (SLM) and soil sustainability has been recognized. Furthermore, human-induced soil erosion lead to harmful environmental effects and transportation of sediment to water bodies is accompanied by loss of nutrients and eutrophication. Therefore, there is a need to focus on soil erosion outcomes to prevent its environmental impacts and mitigate the negative feedbacks of soil erosion. One of the most important factors that affecting the amount of erosion and sediment yield is soil erodibility (K-factor in USLE), which is an index of soil susceptibility. Moreover, K-factor is one of the 6 effective factors on soil erosion in universal soil loss equation and mainly is representative of soil properties. Regarding the difficulty of soil erodibility ´s measurement, therefore we need to an easily measurable parameter. In this study soil aggregate is used as an index of soil erodibility factor. Generally, topography alters from one slope to another one, which conduces to dramatically changes of soil erosion intensity, therefore topography in terms of geomorphometric parameters is effective on soil erosion processes; morphometric analysis and soil erosion modeling are robustly interconnected. Also, digital elevation model (DEM) is a base to extract geomorphometric parameters and the quality of DEM is effective on geomorphometric characteristics. Methods and materialThis study conducted with the aim of modelling the aggregate stability using multivariate linear regression and K-means clustering algorithm as an index of soil erodibility factor. For this purpose a study area with an approximate area of 20000 hectares selected. This area is located in Dehdez which is in the north east of Khuzestan province. Based on the climatologic data this area has xeric and thermic regimes. The main land uses in this area including rangeland and forest and in the rangeland the crop cover is mostly grasses. According to the purpose of this study and degree of homogeneity the soil sampling accomplished using completely randomized method. From each land use 25 soil samples collected (the depth of soil sampling was 0-30 cm). Then the soil samples prepared and the mean weight diameter (MWD) as an index of soil aggregate stability using wet sieving, soil texture with hydrometer method and organic carbon content measured in at least 3 replications. In another part of this project the digital elevation model (DEM) of study area extracted from SRTM (Shuttle radar topographic mission) with the spatial resolution of 30 m. After DEM preparation all preprocessing operations performed on DEM using Arc Hydro extension in ArcGIS 10.3 software in order to remove sinks and enhance the quality of DEM. In the next step the primary and secondary geomorphometric parameters extracted from this DEM using ArcGIS 10.3 and SAGA 6.3. software. Finally, multivariate linear regression and K-means clustering models developed between geomorphometric parameters and soil properties as dependent variables and aggregate stability as independent variable to achieve statistical indices in order to evaluate developed models. Results and discussionOur results showed that there was a significant correlation between some geomorphometric parameters and soil aggregate stability; therefore there is a possibility to apply these parameters in order to parameterize aggregate stability. Moreover, the results of modelling indicate that regression models using geomorphometric parameters and soil properties was able to cover approximately 75 and 70 percentage of spatial variation of aggregate stability in the rangeland and forest land use of the study area, respectively. While clustering-regression models were able to explain 77 and 82 percentage of the spatial variation of the aggregates stability in the first and second cluster respectively. Also, the results of validation of developed models in this study showed that the root mean square error (RMSE) of regression models for rangeland and forest land use was 0.33 and 0.26 respectively and RMSE of clustering-regression models for first and second clusters was 0.93 and 0.62 respectively. According to importance of soil aggregate stability on soil erodibility factor (K-factor) and the difficulty of soil erodibility ´s measurement therefore these developed models are useful tools in order to predict soil erosion and based on the distribution of soil erosion and deposition using STI (Sediment transport index) and TWI (Topographical wetness index) could be able to select and apply the best management practices in the critical areas. Indeed STI map and TWI map are indices of spatial distribution of soil erosion and deposition in the studied area therefore using these geomorphometric indices we able to control soil erosion and its negative feedbacks. ConclusionRegarding the difficulty of soil erodibility ´s measurement therefore we used some indices to simplify this process and our results illustrated that it is possible to develop some regression models in order to estimate aggregate stability as an index of soil erodibility. In summary our results confirm that geomorphometric parameters are easily available parameters based on the DEM to predict soil erodibility. Keywords: Digital elevation model (DEM), geomorphometry, modelling, soil erosion, topographical indices
Volume 42 - Issue 2
Plant Nutrition, Soil Fertility and Fertilizers
Samira Mikhi; Behnam Doulati; Amir Rahimi
Abstract
Introduction The Lamiaceae is a chief medicinal and aromatic plant family. It is a family of extensive diversity and variety with international distribution. It is known that most of their properties are due to the essential oils they contain as products of their secondary metabolism. The metabolic performance ...
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Introduction The Lamiaceae is a chief medicinal and aromatic plant family. It is a family of extensive diversity and variety with international distribution. It is known that most of their properties are due to the essential oils they contain as products of their secondary metabolism. The metabolic performance of living organisms can be distinguished into primary and secondary metabolisms. Secondary metabolites represent features that can be expressed in terms of ecological, taxonomic, and biochemical differentiation and diversity. The antioxidant properties of the volatile oils are not as robust as that of water-soluble constituents. Oregano, a member of the family is an herb that has been cultivated for centuries in the Mediterranean region, although now it can be found in most continents. Because of variability in composition and origin of different Origanum spp, the antioxidant capacity reported can vary substantially. In one study, oregano had the highest total antioxidant capacity and phenolic content compared with other Lamiaceae herbs, thyme, sage, rosemary, mint, and sweet basil. Istanbul oregano (Origanum vulgare ssp. hirtum (Link) Ietswaart)is a perennial plant with dense indumentum, white and pink flowers, strong fragrance, and flowering in July and August. It grows widelyin the Thrace, Marmara, and west and southern regions of Turkey. The plant is richer in oil and carvacrol content than O. onites and if improved, agronomic affairs would offer a better alternative. The environmental and social reasons indicate that conventional agriculture constitutes a continuous pressure contributing to the progressive worsening of environmental conditions. In this matter, the increasing use of saline irrigation water is one of the main factors resulting in salt accumulation in the plant rhizosphere. In this situation, soil degradation emphasized the need to develop strategies of salt affected soil reclamation. One of the possible solutions is to use humic substances. Micronutrients are essential elements that are used by plants in small quantities. Yield and quality of agricultural products increased with micronutrients application; therefore, human and animal health is protected with a feed of enrichment plant materials. Each essential element only can perform its role in plant nutrition properly when other necessary elements are available in balanced ratios for the plant. The aim of this trial was to study the effects of some micronutrients and humic substances on the antioxidant activity of the plant. Materials and Methods The trial was conducted at the experimental fields (37.53° N, 45.08° E, and 1320 m) and the greenhouse of the Agronomy Department, Faculty of Agriculture and the Lab of Biology Department, Urmia University, during 2015-2016, prepared in a randomized complete block design in three replications, using Fe, Zn, Cu, humic acid and their incorporation (3 g Lit-1) spray as treatments. The land was plowed at the optimum moisture level (field capacity) and leveled. Phosphorus and Potassium fertilizers were applied at pre-sowing time in autumn, according to soil analysis and farrowed in 50 cm. The seeds for sowing were obtained from Turkey. Sowing was done in green house at the Department of Horticulture, Faculty of Agriculture, Urmia University, during the period from 21. 03. 2015 till 06.05.2015. The seeds were sowed in plastic pots filled with soil, sand, and peat moss substrate as a material for germination. After that sowing was irrigated regularly depending on weather conditions and development stage of plants. Seedlings were harvested and planted in the experimental field. Nitrogen fertilizer was used in planting time, and vegetative phase according to soil analysis. Irrigation was conducted depending on plants need. Harvestings were done in 50% flowering. Physical and chemical characteristics of the field soil were determined by the standard method. Total phenolic content, flavonoid content, DPPH radical scavenging activity, nitric oxide radical scavenging activity, and Chain-breaking activitywere determined. Results The aim of this study was to increase the amount of oregano essential oil, and the use of micronutrients and humic substances increased the essential oil content of the plant. According to the results, the highest and lowest leaf dry weight was related to Zn+Cu+HA+Fe and Cu treatments, respectively. The highest essential oil content (3.50%) was recorded in Zn+Cu+HA and the lowest (2.28%) in Fe+HA treatments. The highest amount of total phenol in the plant leaves (72.7 g gallic acid/ 100 g DW) in Zn, flavonoid content (88.8 g quercetin/ 100 g DW) in HA and DPPH radical scavenging activity (74.1%) were observed in Fe+Cu+Zn+HA sprayings. In addition maximum nitric oxide radical scavenging (50.3%) and Chain-breaking activity (70.7 -Abs-3/min/mg extract) were observed in Zn and Fe+Zn treatments, respectively. In conclusion, the type of micronutrients and humic substances can affect the quality traits such as essential oil and antioxidant activity and according to the use target of the plant, combined and non-combined consumption of micronutrients, and humic substances can be recommended.
Volume 38 - Issue 2
S. Rahi; H. Bahrami; M. J. Sheikh Davoudi
Volume 39 - Issue 1
M. Khorramian; S. Salimpour
Abstract
IntroductionThe area cultivated for wheat is about 550000 ha in Khuzestan province. Limited rainfall conditions and incompatibility of rainfall patterns with wheat crop requirements leads to decreasing of soil moisture and drought stress. Studies have shown that water supply affects the uptake of nutrients ...
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IntroductionThe area cultivated for wheat is about 550000 ha in Khuzestan province. Limited rainfall conditions and incompatibility of rainfall patterns with wheat crop requirements leads to decreasing of soil moisture and drought stress. Studies have shown that water supply affects the uptake of nutrients and nutrient use effeciency. On the other hand, the benefical effect of the application of zinc and potash nutrients under different water stress in Khouzestan is not convenient for farmers. Therefore, this study aimed to determine the effect of drought stress and zinc and potash in silty clay loam soil on yield and water use efficiency (WUE) of wheat. Materials and Methods The experiment was carried out in Safiabad Agricultural Research Center (SARC) of Dezful, Khuzestan during the years of 2008-09 and 2009-10. Before the experiment, initial composite soil samples (0-30 cm & 30-60cm depth) were collected from the experimental plots and were analyzed. The soil was silty clay loam with low organic matter content (OC=0.5-0.75%) and well drained without salinity (ECe=0.27-1.3 ds m-1). On the other hand, micronutrient content of the soil (Fe, Mn and Cu) was higher than the threshold limit. The design was a split plot on a completely randomized block design with three replications. The main plot consisted of three different levels irrigation after 50 (I50), 75 (I75), and 100 mm (I100) evaporation from evaporation pan and sub plots included three levels of fertilizers, without micronutrient (F0), fertilizing based on soil analysis value (F1), and fertilizing basesd on 1.5 times more than the recommended level (F2). Every subplot size was 3.6 m x 10m. The studied cultivar was Chamran and the sowing date was on November with a density of 400 seeds per m-2 and harvested during May in both growing seasons. Soil moisture content was measured before every irrigation in root zone depth using the weighning method. Applied water was measured using flow meter for every treatment. After seed ripening, grain yield per hectare and component yield were measured from the total area of each treatment. Statistical analysis was performed using MSTATC software packages and mean comparison was also performed using Duncan’s Multiple Range Test (DMRT). Results and Discussion The rainfall during plant growth for first and second years was 68 and 221 mm respectively. The mean temperature of Mars and April in the seconed year was 26.1 and 34°C increasing by about 1.4 and 1.9°C compared to the first year. The higher temperature in the second year increased heat stress which led to yield decrease. Irrigation water consumptions in first year for I50, I75, and I100 treatment were 960.6, 804.1 and 682.2 mm and in the second year 182,115 and 95 mm respectively. Higher rainfall in the second year in comparison with the first year led to decrease in number of irrigation events. All the studied parameters except for 1000-grains weight and number of grains per spike were significantly influenced by different levels of fertilizer treatments.The highest yield belonged to fertilizing based on soil test results (F1), (40 kg K per ha, Zinc Sulfat with 200 kg per ha potash) while the lowest yield was found in the control treatment(F0). Cakmak et al. (1996) and Yilmaz et al.(1997) also observed similar responses. A similar trend was observed in the biological yield, number of spike and 1000-grains weight. Increasing rates of K and zinc(up to 40 kg.ha-1) increased the values of crop parameters such as biological yield, number of spike , 1000-grains weight and water use efficiency and thereafter higher levels of K and zinc fertilizer (F2 treatment) led to their decline. Analysis of variance on yield showed that irrigation regime, potash and zinc fertilizer levels were significantly different (p<5%), so that the highest and the lowest yield belonged to I50F2 with 673.5 gr m-2 and I100F0 with 450.3 gr m-2 respectively. Although there was no significant difference between F1 and F2 treatments, increasing the applied fertilizer in I50 treatment increased yield and water use efficiency. On the other hand, applying potash and zinc fertilizer more than recommended levels in soil under moisture stress (I75 and I100), resulted in decreased yield. Conclusion The overall results from this study indicated that it is essential to avoid applying potash and zinc fertilizers over recommended values in soil under moisture stress conditions. Intraction between different irrigation levels in combination with fertilizer showed that I75F1 with yield and WUE, of 6.4 t ha-1 and 1.28 kg m-3 respectively could be recommended.
Volume 40 - Issue 1
F. Shahbazi
Volume 47 - Issue 1
Agricultural mechanization
Roohollah Yousefi; Alireza Allameh
Abstract
Introduction Mechanization is one of the main factors in the development of agriculture. Agricultural mechanization, as a basic approach in the production of agricultural products, provides goals such as timely performance of agricultural operations, reduction of production costs, reduction of labor ...
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Introduction Mechanization is one of the main factors in the development of agriculture. Agricultural mechanization, as a basic approach in the production of agricultural products, provides goals such as timely performance of agricultural operations, reduction of production costs, reduction of labor intensity, quantitative and qualitative improvement of production and, in principle, the possibility of Economic production. There are inequalities in the development of agricultural mechanization, which is partly affected by natural factors, but human factors also play a significant role in its occurrence. Planning for the development of mechanization is one of the most important components in the development plan of the agricultural sector. The requirement for correct planning regarding agricultural mechanization depends on recognition of the existing situation. Knowing and evaluating the development indices of rice mechanization is necessary for the correct selection and optimal use of rice machines and timely and quality agricultural operations to be used as basic information in the calculation of rice mechanization projects and economic analyses. In this research, the indices of rice mechanization in the central and southern regions of Gilan province were studied with the aim of estimating the number of machines needed in rice cultivation.Methodology Gilan province is one of the northern provinces of Iran, with an area of 14711 square kilometers which stands the second ranking (31% of total) in terms of area harvested. A study was conducted during the years 2020 and 2021 for determination of indices that govern the mechanization development in the central and southern regions of Gilan province. The studied areas were as rasht and khomam (in the central areas of Gilan province) with an area under rice cultivation of 62430 hectares and roudbar (in the southern areas of Gilan province) with an area under rice cultivation of 3375 hectares. The field method or field study was employed in terms of broad-based (holistic) and deep-based (depth-based) methods and its subset based on questionnaire for data collection in this research. Due to the lack of access to all villages of each city, one village was randomly selected and after checking their conditions, the relative homogeneity of the area was determined and the obtained information was generalized to other places. Collecting of data was done by completing the questionnaires through available statistical sources, field surveys and interviews with farmers. Data were collected from reliable authorities such as the Gilan agricultural jihad organization, agricultural jihad management of the cities, agricultural jihad centers, and the statistics of the Ministry of Agricultural Jihad. From the obtained data, the indices determining the state of mechanization, working days and farm productivity were calculated.Results and Discussion The results revealed that in the central and southern regions of Gilan, the degree of mechanization was 65.1 and 78.9 percent, the level of mechanization was 2.71 and 9.12, horsepower per hectare and the average capacity of mechanization was 415.74 and 782.10 horsepower in hour per hectare, respectively. On average, in the central and southern regions, there was one tractor for every 35 and 5 hectares, a tiller for every 5 and 11 hectares, a transplanter for every 46 and 31 hectares, and a combine harvester for every 88 and 56 hectares, respectively. According to the results, the number of machines in the tilling and spraying stages is more than the estimated number of machines in the studied areas. The number of available machines in the central areas was 77.1 and 55% more in tillage and 35.6 and 41.2 percent less in planting and 25.8 percent more in the southern areas in tillage and 79.7 percent and in 56.4 plantings and 2.3 percent less than the estimated number.Conclusion The degree of mechanization for tillage and transplanting operations in the central and southern regions of Gilan province demonstrated a good circumstance based on the sixth state plan of development. According to the expectations, by the end of the sixth development plan, the degree of mechanization in plant protection and harvesting operations, there is a need to reinforce and import more machines. The level of rice mechanization was higher in the south region than the central. From the above-mentioned reasons, the level of mechanization of rice in the southern region can be attributed to the multiple usage of the driving machines for paddy fields and other crops, the low area under rice cultivation and the large number of tillers and tractors, the lack of companies providing mechanized services, and little time available to farmers to carry out land preparation, transplanting, protection, and harvesting in these regions. The findings also showed that tractors and tillers, which were the most important sources of power supply, were not evenly distributed across the central and southern regions. In some cases, tractors and tillers were used in irrelevant tasks such as transportation and handling. According to the results, in the stages of tillage and spraying, the number of available machines is more than the estimated ones in the studied regions. According to the results, the number of machines available in the central areas in Tillage (Primary tillage, Secondary tillage, Puddling, Leveling) is 77.1% and Plant Protection (spraying and weeding) 55% more and in planting 35.6 and harvesting (Rice reaper, rice combine harvester, baler) 41.2 percent less than the estimated number. The number of machines available in the southern regions in tillage is 79.7% and harvesting 25.8% percent more and in planting 56.4 and Plant Protection 2.3% percent less than the estimated number. The comparison of the current conditions of these areas with the estimate shows that there is no proper planning in the supply and distribution of agricultural machines according to the cultivated areas. This shows the necessity of planning to establish more balance to create appropriate and homogeneous conditions for the distribution of agricultural machines in the studied regions. Keywords: Field Efficiency, Mechanization Index, Number of Machines, Rice, time opportunity, Working days.
Volume 41 - Issue 2
Precision Agriculture
ُseyyed Mohammad Mousavai; Hojat Emami; Gholam Hosain Haghnia
Abstract
Extended abstractIntroductionKnowledge about the soil quality in agriculatral lands and natural resources is essential for achievement the best management and maximum economic efficiency. The land use change is the important human activity in environmental ecosystems, which effect on some soil processes ...
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Extended abstractIntroductionKnowledge about the soil quality in agriculatral lands and natural resources is essential for achievement the best management and maximum economic efficiency. The land use change is the important human activity in environmental ecosystems, which effect on some soil processes such as microbial activity, mineralization of carbon and nitrogen content. In addition, land use has an important role on temporal and spatial variation of soil properties and quality. Agricultural practices may affect positive or negative effect on soil quality. Intensive cultivation of plants decreases soil physical and quality, as a result of this yield of plants, production efficiency and environment quality decrease. In this research, the effect of three land uses on soil physical, fertility and quality properties were studied. Materials and methodsThe studied area (Hossein abad) is located 30 km far from the northern Nehbandan town (South Khorasan, Iran).To study the effect of land uses change on soil properties were selected three land uses including pomegranate (Punica granatum ), olive (Olea europaea) and wheat (Triticum aestivum ). The 45 soil samples (15 samples from each land use) were taken from surface soil (0-30 cm). Then some soil physical and fertility properties which affect the soil quality were measured and the effect of land use change from wheat cultivation to olive and pomegranate gardens during the recent 20 years were studied. In addition, soil quality in each land use was determined based on cornel university test. To compare soil properties and quality, the randomized complete block design was applied.Results and discussionThe results showed that land use change had a significant effect on organic carbon, mean weight diameter of aggregates (MWD), water stable aggregates (WSA), macro nutrients (N, P, and K), and some micro nutrients (Fe and Mn) (P < 0.001). Comparison of means demonstrated that the difference between organic carbon content in olive and pomegranate land uses was not significant, and the content of OC in both land uses was significantly higher than wheat land use. Olive and pomegranate land uses cause to stability of soil structure increase, probably due to reduction the traffic of wheals and also somewhat increasing the organic carbon as a result of littering. Therefore, the MWD in olive land use was significantly higher than two land uses and the lowest value was obtained in what land use. Also, the value of WSA in three land uses was significantly different (P < 0.05) and their content in olive and wheat land uses were the maximum and minimum, respectively. The concentration of total nitrogen in pomegranate land use was more significant than two other land uses (P < 0.05). But the concentration of phosphorous (P), potassium (K), Fe and Mn in wheat land use was the highest content and significantly greater than other two land uses. Despite the concentrations of P, K, and Fe nutrients in pomegranate land use were the lowest value, but, there were no significant difference between the concentration of them in olive and pomegranate land uses. It seems that this variation especially P and Fe is probably due to pH and the Ca and Mg concentration and creation insoluble component of Fe, Mn and P in these land uses.According to the results of cornel university test, soil quality in garden land uses was decreased and the range of soil quality score was varied from 49.5 (olive) to 61.2 (wheat). Among the soil properties affecting the soil quality, fertility and chemical properties such as electrical conductivity (EC), absorption sodium ratio (SAR) and somewhat pH of soil saturated extract decreased the soil quality in olive land use. Also, OM, Fe, Zn, and Mn decreased the soil quality in 3 land uses, of course in olive and pomegranate land uses, micro nutrients (Fe and Mn) had the more effect on decreasing the soil quality compared to wheat land use. In addition, bulk density (Bd), mean weight diameter of aggregates (MWD), aeration porosity (AC), P, K, and Cu contents increased soil quality in all 3 land uses.ConclusionIn general, when wheat land use change to olive and pomegranate land uses decreased some soil properties and quality in arid area of Nehbandan, probably due to low quality of irrigation water.
Volume 44 - Issue 1
Soil Chemistry and Pollution
Masoumeh Sadeghi Poor Sheijany; Fatemeh Shariati; Nafiseh Yaghmaeian Mahabadi; Hassan Karimzadegan
Abstract
Introduction One of the most important results of population growth, urbanization, and industrialization is the increase of urban waste. Accumulation of municipal solid waste produces toxic leachate that can transfer contaminants to the soil and alter its quality, especially in vulnerable forest ecosystems. ...
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Introduction One of the most important results of population growth, urbanization, and industrialization is the increase of urban waste. Accumulation of municipal solid waste produces toxic leachate that can transfer contaminants to the soil and alter its quality, especially in vulnerable forest ecosystems. This study was carried out to determine the properties of the soil of the Saravan municipal solid waste disposal site that is located in a part of the Hyrcanian forests, Rasht, Guilan province, which have been affected by the activity of the open dumpsite; Determining the minimum data set (MDS) and evaluating the quality adjacent soil to the dumpsite, the route affected by leachate and downstream lands, through soil quality indices such as simple integrated quality index (IQISA), weighted integrated quality index (IQIW) and Nemoro quality index using total data set (TDS) and MDS, and comparing them with each other.Materials and Methods Based on the distance from the disposal site, slope, height, and the route of leachate, from 32 sampling points with the same vegetation, a total of 32 composite samples were prepared in plots 10×10 from (five sub-samples from four heads and the middle by a polyethylene hand auger) a depth of 0-15 cm in June 2019.The soil properties including pH, clay, silt, sand, available phosphorus (Pava), copper (Cuav), zinc (Znav), and iron (Feav), total nitrogen (N), cation exchange capacity (CEC), electrical conductivity (EC), organic carbon (OC), basal respiration (BR), microbial biomass carbon (MBC), the metabolic quotient (qCO2) and enzymatic activities of Urease (UR) and alkaline phosphatase (ALP) were measured. One-way analysis of variance (ANOVA) and independent comparison tests was used to compare the results of the soil samples in areas exposed to dumpsite activities and control. Six properties were selected as MDS using principal component analysis (PCA). The models of the simple integrated quality index (IQIsa), weighted integrated quality index (IQIW), and the Nemoro index were used to determine soil quality. One-way ANOVA and Duncan’s multiple range tests were used to compare the mean soil quality indices in the areas around the disposal site, leachate-affected route, and downstream lands. The possible relationship between chemical, physical and biological properties was investigated by calculating Pearson’s correlation coefficients.Results and Discussion The results showed that the value of soil properties including Feav, EC, Pav, N, Znav, Cuav, OC, BR, MBC, the enzymatic activities of UR and ALP is significantly different from the control (p < 0.01). The properties of Pav, Cuav, EC, clay, silt and MBC were selected as MDS, which can describe 73% of changes in the soil quality. Evaluation of the soil quality through Nemoro index, using MDS and TDS (IV and III, respectively) at different distances from the dumpsite was the same as the control. The values of IQIsa and IQIw using MDS did not show any significant difference with the control in all routes exposed to the activity of the disposal site, except around the dumpsite. However, the degree of soil quality through the overall average IQIsa and IQIw, using MDS in all areas exposed to the dumpsite was the same as the control. The results of IQIsa and IQIw, using TDS were so different so that the values of IQIsa and IQIw, using TDS in the path of leachate and lands downstream of the disposal site showed a significant difference with the control (p < 0.01). Also, the quality degree through the overall mean value of IQIsa and IQIw, using TDS (III and IV, respectively), around the disposal site and the path of leachate were different from the control (II and III, respectively).The Saravan municipal waste disposal site is located in an area, with a Mediterranean climate, with high relative humidity and rainfall. It has increased the possibility of leachate production. On the other hand, with the leachate flowing along the sloping path of 15%, especially after each rainfall in the area, the soil is contaminated by leachate and transfer downstream. Also, Leachate is discharged from the disposal site downstream, into the river, which is used to irrigate agricultural land downstream of the dumpsite. The results of changes in IQIsa and IQIw by TDS can indicate the possible consequence of the leachate effect from the disposal site on the path to the soil of downstream farms.Conclusion According to the objectives of the research, it seems that soil properties including Feav, Pav, EC, N, BR, MBC, and the enzymatic activities of UR and AIP have been affected by the activity Saravan solid waste disposal site. Investigating the results of the quality indices using MDS and TDS showed that IQIsa and IQIw, using TDS can better represent the effect of waste disposal site activity on soil quality. Significant differences of the IQIsa and IQIw, in the leachate route and downstream agricultural lands with the control can probably be due to the effect of leachate and leaching of soil around the leachate route and its transfer downstream. Considering the same quality results in the area exposed to the activity of the disposal site with the control through the Nemoro index, using MDS, TDS, it can be concluded that Nemoro index does not have the required sensitivity to describe the effect of waste disposal activity on the quality adjacent soil. This study showed that the change of use of the forest area to waste disposal site affected its soil quality in the path of leachate and downstream lands. Therefore, to protect the areas of Hyrcanian forests in the Saravan region and to prevent the reduction of soil quality in the region, taking the necessary measures to separate the municipal solid waste from the origin, to establish leachate collection systems and treatment of leachate before flowing in the forest areas should be carried out.
Volume 46 - Issue 1
Soil Genesis and Classification
mastaneh rahimi mashkale; Mohammad Amir Delavar; mohammad jamshidi; amin sharififar
Abstract
Despite the great use of digital soil maps, the problems of imbalance in classification disrupt the classification performance of many machine learning algorithms, and for this reason, it has attracted the attention of many researchers. Therefore, the aim of this research is to improve the classification ...
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Despite the great use of digital soil maps, the problems of imbalance in classification disrupt the classification performance of many machine learning algorithms, and for this reason, it has attracted the attention of many researchers. Therefore, the aim of this research is to improve the classification of unbalanced soil data using resampling pretreatment technique in three forecasting models including Random forest (RF), Boosted regression trees (BRT) and Multinomial logistic regression (MNLR) in a part of the lands of Zanjan province in Iran.Sampling was done based on a regular grid pattern with 500 meters intervals, and 148 soil surfaces were randomly studied and classified. The region's soils at the subgroup level were in five classes with imbalanced distribution, including Typic Calcixerepts, Typic Haploxerepts, Gypsic Haploxerepts, Typic Xerorthents, and Lithic Xerorthents. Environmental covariates included geomorphological and geological maps, digital elevation model (DEM), and remote sensing (RS), selected by principal component analysis (PCA) and expert knowledge methods AND a number of environmental variables including geomorphological map information, Geological information and features extracted from the DEM were selected as the most effective environmental variables for predicting soil classes and as input to the model. Extraction of environmental covariates was done in ENVI and SAGA_GIS software and modeling of soil-landscape relationship was done using the aforementioned algorithms in Rstudio software. The resampling technique was applied to the minority and majority soil classes prior to modeling.The results showed that using original data that have imbalanced classes for mapping resulted in loss of the minority classes and relatively low Kappa agreement values and overall accuracy for RF (ovrall=65%, k=0.32) and BRT models (ovrall=60%, k=0.35). However, after resampling the data, two overall accuracy and Kappa coefficient statistics increased in all models. In addition, the BRT model provided an acceptable estimate by maintaining the minority classes and the Kappa coefficient of 0.64 and the overall accuracy of 75% in the spatial prediction of soil subgroups. The producer accuracy (PA) and user accuracy (UA) results showed that the two classes of Gypsic Haploxerepts and Lithic Xerorthents, which were excluded when training using imbalanced datasets in RF and BRT algorithms, showed significant improvement after balancing the data. Results show that they were well predicted in RF algorithm (UA =100%, 78%) and BRT algorithm (UA= 60% and 70%) using treated data. Also, these minority classes showed Producer accuracy in RF algorithm (PA= 75%, 88%) and BRT algorithm (PA=100%, 78%) in compared to zero accuracy when training using imbalanced data. On the other hand, the validation results of the MNLR algorithm showed that despite maintaining the minority classes after balancing the data, the minority classes were predicted with less accuracy. Results showed that modeling using imbalanced distribution of class observation caused uncertain maps with minority classes being lost and relatively poor accuracies. After data treatment, with over- and under-sampling, all models showed significant improvement in maintaining the minority classes, in evaluations. Data resampling technique can be a useful solution for dealing with imbalanced class observations to produce more certain digital soil maps.Despite the great use of digital soil maps, the problems of imbalance in classification disrupt the classification performance of many machine learning algorithms, and for this reason, it has attracted the attention of many researchers. Therefore, the aim of this research is to improve the classification of unbalanced soil data using resampling pretreatment technique in three forecasting models including Random forest (RF), Boosted regression trees (BRT) and Multinomial logistic regression (MNLR) in a part of the lands of Zanjan province in Iran.Sampling was done based on a regular grid pattern with 500 meters intervals, and 148 soil surfaces were randomly studied and classified. The region's soils at the subgroup level were in five classes with imbalanced distribution, including Typic Calcixerepts, Typic Haploxerepts, Gypsic Haploxerepts, Typic Xerorthents, and Lithic Xerorthents. Environmental covariates included geomorphological and geological maps, digital elevation model (DEM), and remote sensing (RS), selected by principal component analysis (PCA) and expert knowledge methods AND a number of environmental variables including geomorphological map information, Geological information and features extracted from the DEM were selected as the most effective environmental variables for predicting soil classes and as input to the model. Extraction of environmental covariates was done in ENVI and SAGA_GIS software and modeling of soil-landscape relationship was done using the aforementioned algorithms in Rstudio software. The resampling technique was applied to the minority and majority soil classes prior to modeling.The results showed that using original data that have imbalanced classes for mapping resulted in loss of the minority classes and relatively low Kappa agreement values and overall accuracy for RF (ovrall=65%, k=0.32) and BRT models (ovrall=60%, k=0.35). However, after resampling the data, two overall accuracy and Kappa coefficient statistics increased in all models. In addition, the BRT model provided an acceptable estimate by maintaining the minority classes and the Kappa coefficient of 0.64 and the overall accuracy of 75% in the spatial prediction of soil subgroups. The producer accuracy (PA) and user accuracy (UA) results showed that the two classes of Gypsic Haploxerepts and Lithic Xerorthents, which were excluded when training using imbalanced datasets in RF and BRT algorithms, showed significant improvement after balancing the data. Results show that they were well predicted in RF algorithm (UA =100%, 78%) and BRT algorithm (UA= 60% and 70%) using treated data. Also, these minority classes showed Producer accuracy in RF algorithm (PA= 75%, 88%) and BRT algorithm (PA=100%, 78%) in compared to zero accuracy when training using imbalanced data. On the other hand, the validation results of the MNLR algorithm showed that despite maintaining the minority classes after balancing the data, the minority classes were predicted with less accuracy. Results showed that modeling using imbalanced distribution of class observation caused uncertain maps with minority classes being lost and relatively poor accuracies. After data treatment, with over- and under-sampling, all models showed significant improvement in maintaining the minority classes, in evaluations. Data resampling technique can be a useful solution for dealing with imbalanced class observations to produce more certain digital soil maps.
Volume 45 - Issue 2
Roghayeh Shahriaripour
Abstract
Introduction Phosphorus (P) is the second nutrient and plays a key role in plant growth. The availability of P in the soil depends on the P fractions, which influence the primary productivity of agricultural ecosystems. Having sufficient and accurate information about soil mineral phosphorus is very ...
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Introduction Phosphorus (P) is the second nutrient and plays a key role in plant growth. The availability of P in the soil depends on the P fractions, which influence the primary productivity of agricultural ecosystems. Having sufficient and accurate information about soil mineral phosphorus is very important for the development of sustainable agriculture in arid regions. Awareness of phosphorus deformation in different soils is also very important for phosphorus fertilizer recommendation. When phosphorus is used in its soluble forms, it is rapidly converted into unusable forms for the plant. Native soil phosphorus is often in unusable form for the plant. Therefore, having enough information about phosphorus deformation in different soils is very important to recommend phosphorus fertilizer. The objective of this study was to find out the effects of long-term use of different sources of phosphorus on available P for pistachio plants in southeast Iran.Materials and Methods The aim of this study was to find the effects of long-term use of different sources of phosphorus fertilizers that can be used for pistachio plants. For that, 168 different soil samples from 63000 ha of Sirjan pistachio orchards of Kerman province. Jiang and Gu method was used to isolate and determine the mineral forms of phosphorus in the soil. Each P fraction was extracted as follows: 1g (oven-dry weight) of sample soil weighed out into a 50 mL polyethylene centrifuge tube. A volume of 40 mL of the first extractant, NaHCO3 (Table 1) was added and placed in an automated mechanical shaker at 25° C with 110 rpm for 1 h to allow time for the solution top equilibrate. The tubes were then centrifuged at 6000 × g for 15 min and the supernatant was carefully filtered through Whatman No. 42 with minimum loss of soil. Reactive P in the supernatant was determined using the ascorbic acid method at 882 nm. This method separates phosphorus in the forms of di calcium phosphate, octa calcium phosphate, aluminum phosphates, iron phosphates, occluded phosphates and apatite. The data showed that Ca10-P was the most abundant P forms in the soils tested. Results and Discussion Results showed that the total P was high in these soil samples and the abundance of P fractions was in order to Ca10-P type≥ Al-P >Ca2-P type> Occluded P ≥ Fe-P > Ca8-P type in two depths. These results suggested that continuous P application leads to plant available P convert into unavailable P forms such as Ca10-P. results indicate that NaOH-extractable P has resulted from active Fe oxides. Also, by comparing two depths of soil in the study area, it can be concluded that the occupied phosphorus in the surface layer is more than the deep layer. Finally, it can be concluded that by increasing the stability of various forms of phosphorus, their contribution to other forms of phosphorus increases, so that the concentration of apatite is much higher than phosphate-calcium phosphate. Results showed the amount of available phosphorus (Ca2-P) in the surface layer is more than the deep layer, which can be attributed to surface application of Phosphorus fertilizers. However, there are sections where phosphorus in the surface layer and the bottom is almost equal. Amount of this form of P is less than Al-P and Fe-P. It may be due to increase in Al and Fe contents in in calcareous soils.Conclusion High amounts of total P clarifies that by optimally managing the use of phosphorus fertilizers and soil conditions, the required P of the plant can be provided without additional use. From the results reported in this study, it appears that in the calcareous soils tested, the abundance of different forms of P was in order Ca10-P type≥ Al-P >Ca2-P type> Occluded P ≥ Fe-P > Ca8-P. furthermore, it observed that Fe-P, Al-P and Oc-P are important forms of P and on average constitute 30% of the sum of inorganic P forms. These findings demonstrate that the ability of NaOH to extract Al-P will be reduced with an increase in Al-P content and that NaOH is unable to remove Al-P completely. Therefore, it seems that more research is needed to find some light on whether NH4F can be omitted from the regular P fractionation schemes in the highly calcareous soils of Iran.
Volume 46 - Issue 2
Soil Genesis and Classification
Mahyar Moshtaghi; hasan ramezanpour; Nafiseh Yaghmaeian Mahabadi; Mahmoud Shabanpour
Abstract
Introduction: Soil classification categorizes soils into different classes on the basis of their distinguishing characteristics and provides a structured conceptual framework for describing and understanding soil properties. There are two soil classification schemes that are generally regarded as having ...
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Introduction: Soil classification categorizes soils into different classes on the basis of their distinguishing characteristics and provides a structured conceptual framework for describing and understanding soil properties. There are two soil classification schemes that are generally regarded as having worldwide application, the Soil Taxonomy (ST) and the World Reference Base (WRB) which are also popular in Iran. These systems of classification consider diagnostic horizons and factors of soil formation as the basis of classification. The aim of this study was to determine the classification of soils of tobacco farms in the Talesh County of Guilan Province based on ST (2022) and WRB (2022) according to the soil diagnostic characteristics, then comparing two systems for soils of tobacco farms to determine the ability of better description of soils by these two systems of soil classification.Materials and Methods: Talesh County is considered to be the most important tobacco production areas in Guilan Province and IRAN. The most extensive area of tobacco cultivation in Guilan Province is located in this County and in Jokundan and Mountain districts. The study area has a humid climate with cold winter and hot summer. The mean annual temperature is between 15.6 and 17.2 degrees Celsius and the annual rainfall is between 786 and 1370 mm. Based on the map of moisture and temperature regimes of Iran and with the help of jNSM software, the moisture and temperature regimes were determined as Udic and the Thermic respectively. In the study area twenty pedons (eight pedons for Mountain and twelve pedons for Jokandan) were described and the morphological characteristics of the pedons layers were studied in the field according to the Soil Survey Manual. Then, the soil of each horizon was collected, air-dried, and sieved by passing through a 2 mm sieve before analyzing the properties of the soil. Soil pH, Electrical Conductivity, Texture, Organic Carbon, Calcium Carbonate Equivalent, Cation Exchange Capacity and Base Saturation were determined in all the samples according to Methods of Soil Analysis. Soils were then classified according to classification criteria of ST (2022) and WRB (2022) systems. For showing changes of tobacco farms soils, eleven pedons were selected as representative pedons and the reference between ST (2022) and WRB (2022) was established for tobacco soils at the level of the subgroup or secondary classification unit.Results and Discussion: The results revealed that according to ST (2022), representative pedons of Mountain district were classified as Entisols, Inceptisols and Mollisols orders while, Jokandan had Entisols, Inceptisols, Mollisols and Vertisols pedons. WRB (2022) Reference Soil Groups (RSGs) for Mountain was Regosols, Umbrisols and Phaeozems and for Jokandan district were Fluvisols, Cambisols, Phaeozems and Vertisols. At lower levels of classification, ST (2022) uses climatic data as soil moisture regime whereas WRB (2022) does not use. Therefore, the suborders or great groups of all soils were separated based on the Udic moisture regime. Finally, representative pedons were classified as Typic Udorthents, Mollic Udifluvents, Oxyaquic Udifluvents, Typic Humudepts, Dystric Eutrudepts, Typic Hapludolls, Fluventic Hapludolls, Aquic Argiudolls, Typic Argiudolls and Aquic Hapluderts at great group level. In regard to the WRB (2022), in the secondary levels, each section had its own series of principal and supplementary qualifications. Among those, the principal qualifications were mainly Eutric, Cambic and so on, and the supplementary qualifications were mainly Clayic, Loamic, Siltic, Humic and so on. Conclusion: It was found that when compared with ST (2022), the WRB (2022) had stronger abilities to distinguish soil properties for tobacco cultivation which was mainly reflected in the following aspects: 1- The climate-related soil moisture regimes were generally used to classify the suborders in ST (2022). It was found that the soil moisture status of all pedons was Udic, as well as the fixed format of naming soils in ST (2022), Therefore, divisions were limited in the suborders, 2- The flexibility of WRB with the utilization of multiple qualifiers brings out more sensitivity in reflecting soil characteristics in the soil name if compared with Soil Taxonomy. Also, the emphasis put on soil morphology compared with laboratory data makes the system suitable for application in areas with rather modest facilities, 3- The existence of the Mollic or Umbric horizon in pedons is well defined by WRB (2022), while this issue is ambiguous in ST (2022), 4- WRB (2022) have not fixed naming formats, the number of secondary levels qualifiers of the WRB system could be increased or decreased with the number of diagnostic characteristics of the soil pedons. 5- Nomenculture is very complicated in both systems, nevertheless, it is inevitable to transfer information to non- specialist users in a more simpler language, in WRB (2022) this information can be extracted more easily from the soil name.
Volume 44 - Issue 2
Kamran Azizi; Shamsollah Ayoubi; Kamal Nabiollahi
Abstract
Introduction: The parent material and geology have a significant contribution to heavy metal contents and magnetic susceptibility in soils. Magnetic susceptibility is known as the extent of a material’s impact on the magnetic field, which depends on the concentration and the type of magnetic minerals ...
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Introduction: The parent material and geology have a significant contribution to heavy metal contents and magnetic susceptibility in soils. Magnetic susceptibility is known as the extent of a material’s impact on the magnetic field, which depends on the concentration and the type of magnetic minerals in the soil. Magnetic susceptibility measurement is fast, easy, economically convenient, and non-destructive. Mass magnetic susceptibility and frequency-dependent magnetic susceptibility are among the conventionally used parameters. The type of land use is among the main factors influencing magnetic susceptibility distribution in soil. Besides, soil magnetic susceptibility is affected by slope position and different soil properties such as soil organic matter and carbonates. A variety of relationships have been observed between heavy metal concentrations and magnetic susceptibility across various types of soil, parent material and climatic regimes. Generally, magnetic properties have positively correlated with the type and concentration of magnetic minerals as well as the particle size of soil fractions. Besides, magnetic susceptibility has a weak negative correlation with diamagnetic components such as quartz, gypsum, calcite, and organic materials. The main objectives of this study were to i) determine the relationships between magnetic susceptibility (MS) and concentration of some heavy metals such as copper, iron, zinc, and manganese in the surface soils and ii) explore the impacts of land use and geomorphological units on the variability of heavy metals and MS in a semi-arid region in the west of Iran.Materials and Methods: The present study was conducted in Kurdistan province located in western Iran, the area is about 110,000 ha and mean altitude of 2277m above sea level. The area has an average annual temperature of 10.20 °C and an average annual rainfall of 369.8 mm, which dominantly occurs in spring and winter. Besides, the area has soil moisture and temperature regimes of Xeric and Mesic, respectively. The lithological setting of the studied area includes reddish of sandy marls and marl sandstone, river deposits, alluvium-cultivated land, and granite. The studied area was divided into different parts in terms of geomorphology and land use. Soil sampling was done using the stratified random sampling approach. A total of 347 samples were collected from the surface layers (0-30 cm depth) of the studied area. Magnetic susceptibility at both high and low frequencies was measured using a Bartington MS2 dual-frequency sensor. The amounts of all the selected heavy metals including iron, zinc, manganese, copper, and nickel were measured using atomic absorption spectrophotometer. Soil particle sizes, acidity, SOC, CCE and electrical conductivity were measured in all soil samples. The concentration factor and Tomlinson’s Pollution Load Index were calculated. The Spearman correlation coefficient was used to examine the correlation between different parameters. The analysis of variance was used to evaluate the effects of geomorphology and land use on heavy metals and magnetic susceptibility. Spatial analysis was done conducted for some variables (Fe, Mn, Zn, Ni, Cu, and χlf) and the map of variables were created in ArcGIS v.13 software.Results and Discussion: The results showed that the positive significant correlations were observed between heavy metals and silt content and negative significant correlations were observed between heavy metals and sand content. Fine soil fraction compared with coarse fraction has the higher specific surfaces and more susceptible to attract heavy metals. Moreover, positive and significant correlations were obtained between the SOC and heavy metals across various land use types and geomorphic units. Organic matters have a high cation exchange capacity, therefore they adsorb heavy metals and hold them on their surfaces. pH and CCE showed negative and significant correlations with heavy metals and magnetic susceptibility. The positive correlation between heavy metals and magnetic susceptibility in agricultural land, piedmont, and river plains units observed. Also, PLI and CF have a positive correlation with magnetic susceptibility. The t-test showed that a significant difference between agricultural lands and non-agricultural land types and ANOVA results in various geomorphic units of the study area indicated that the magnetic susceptibility between piedmont and mountainous areas were significantly different. Conclusion: Results indicated a significant correlation between magnetic susceptibility and heavy metals. Besides, the magnetic properties of the soil are influenced by its physical and chemical properties that have large impacts on reducing or improving its magnetic field. Significant differences were observed between agricultural lands and non-agricultural lands as well as mountainous and piedmont areas that had different parent materials. These results indicate the great impact of parent materials constituting the soil on the absence or presence of diamagnetism in the region.
Volume 43 - Issue 2
Zahra Abdolahzare; navab kazemi; Saman Abdanan Mehdizadeh
Abstract
Introduction Honeybees play an important role in pollination. However, there are many problems that threaten the life of them. Pollinators can be exposed to insecticides during their application, by contact with residues, or from the ingestion of pollen, nectar or guttation fluid containing insecticide. ...
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Introduction Honeybees play an important role in pollination. However, there are many problems that threaten the life of them. Pollinators can be exposed to insecticides during their application, by contact with residues, or from the ingestion of pollen, nectar or guttation fluid containing insecticide. The increasing use of neonicotinoids means there is a greater potential for pollinators to be exposed over longer periods as systemic insecticides can be found in the pollen and nectar of plants throughout their blooming period (Ellis, 2010). Exposure to insecticides may have lethal or sub-lethal behavioral or physiological effects. The impact of imidacloprid on homing flight was evaluated in field with a 500-m-distance between feeder and hive (Bortolotti et al. 2003). At the concentration of 100 lg kg-1 foragers fed with imidacloprid-added syrup returned to the hive, but this treatment caused a temporary inhibition of the foraging activity, lasting more than 5 h. Foragers fed with 500 and 1000 lg kg-1 of imidacloprid were seen neither at the hive nor at the feeding site, for the 24 h after the treatment (Bortolotti et al. 2003). Decourtye et al (2011) have shown how the RFID device can be used to study the effects of pesticides on both the behavioral traits and the lifespan of bees.In this context, they have developed a method under tunnel to automatically record the displacements of foragers individualized with RFID tags and to detect the alteration of the flight pattern between an artificial feeder and the hive. Fipronil was selected as test substance due to the lack of information on the effects of this insecticide on the foraging behavior of free-flying bees. They showed that oral treatment of 0.3 ng of fipronil per bee (LD50/20) reduced the number of foraging trips. Therefore, the aim of this study was to monitoring and determination honeybee’s behavior in exposure to pesticide using data mining techniques. Materials and Methods Three smart beehive systems developed to monitoring of hive internal conditions. Therefore, each beehive equipped with temperature and humidity (HDC1080, China), vibration (MPU6050, China), and CO2 (CCS811, China) sensors. Data was collected during spraying time for 48 hours and different features of vibration signal in two time-frequency and frequency domains were extracted by MFCC (Mel-Frequency Cepstral Coefficient) algorithm. After that, the most significant features were selected using PCA (Principle Component Analysis) which has been used specifically for extracting information from correlation matrices. Since the spectral dataforms the array of correlated variables containing overlapped information, this approach makes it possible to extractuseful information from high-dimensional data. To choose thenumber of components the cross-validationmethod was used. The extracted principal components wereused as the input variables for the classification model. In this paper, support vector machine with different kernel function including linear, polynomial, MLP, RBF, and quadratic was applied for performing classification. Results and discussion According to the MFCC of internal vibration results, there were dramatic changes in the range of 1800 to 2200 Hz in the time of spraying; also, Spectrogram of MFCC coefficients for the X component acceleration shown intensity of 350 in the frequency of 2000 Hz and time range of 60 to 120 minutes; besides, humidity (8 to 18 %), the amount of CO2 (450 to 530 ppm) and temperature (35 to 39 C) increased during this time.To reduce the dimensionality of data five PCs with minimum estimated mean squared prediction error (0.078) were selected based on Monte Carlo method and used in classifier. Among the five kernels (RBF, linear, MLP, Polynomial, Quadratic), RBF could recognize normal and infected colony with identification rate of 100% and 90%, respectively. Conclusions According to the results temperature, humidity, CO2, and vibration sensors can recognize internal condition of bee hive. Vibration features of honey bees movements were extracted using MFCC followed by PCA in frequency-time domain. Five PCs was selected by cross-validation method and RBF kernel was the best kernel with identification rate of 100% and 90% for normal and infected beehive, respectively. Generally, the vibration signals (that were recorded by acceleration sensor) have shown the best result compare to temperature, CO2, and humidity sensors. It is worth nothing that the use of two temperature and humidity sensors is necessary to monitor and control of beehive internal conditions.
Volume 44 - Issue 3
Samaneh Aryabod; Azam Razavi Nasab; Farhad Nadaf Feyzabadi
Abstract
Introduction The use of organic fertilizers in sustainable agriculture, in addition to increasing the support and activity of beneficial soil microorganisms in order to provide plant nutrients such as nitrogen, phosphorus and soluble potassium and also improves plant growth and yield are so necessary. ...
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Introduction The use of organic fertilizers in sustainable agriculture, in addition to increasing the support and activity of beneficial soil microorganisms in order to provide plant nutrients such as nitrogen, phosphorus and soluble potassium and also improves plant growth and yield are so necessary. In pistachio growing areas due to soil constraints such as salinity and sodium content of the soil, lack of proper structure in most areas, poor soil texture and long irrigation cycle, the use of auxiliary substances such as humic acid, can improve the situation and lead to increase nutrient uptake and increase growth and yield and sustainable production.Materials and Methods This experiment was carried out in a randomized complete block design with three replications in MahVelat. The main plot consisted of four types of humic acid (ordinary solid humic acid, Ferti Plus solid humic acid, Iranian liquid humic acid (all three products of Shimi Gol Feyz Khorasan Company) and American Liquid Humic Acid (HUMAX) and subplot including different application levels (0, first level for solid fertilizers 600 kg and liquid fertilizers 40 liters per hectare and second level for solid fertilizers 800 kg and liquid fertilizers 60 liters per hectare). The number of trees tested was 36 trees of 10-year-old almond cultivar. Solid fertilizer was applied once (March 2016) and liquid fertilizer twice (March 2016 and May 2017). Irrigation was drip (Babler) and studies were considered for one year. In August 2017, by random sampling of the leaves of each tree, the concentration of nitrogen, phosphorus, potassium, calcium and magnesium in the plant leaves and also by sampling the soil of the foot of each tree, some soil chemical properties, including pH, Organic carbon content, available nitrogen concentration and available phosphorus concentration in soil, potassium, calcium and magnesium in soil solution extract were measured. In September 2017, yield components (weight of 100 grains, ounce and emptiness percent) of each tree were measured by weight. The results were statistically analyzed using SAS software and the mean of the experimental data were compared with each other by Duncan's multiple range tests at 5% probability level.Results and Discussion The amount of organic carbon (71.42%), nitrogen (72.22%), and soil potassium (43.01%) with all types of humic acids showed a significant increase compared to the control, but no significant difference was observed between the consumed humic acids. The highest amount of available phosphorus (78/30%) in soil, calcium (54/90%) and magnesium (56.05%) was obtained from liquid ShimiGol and Humax. With increasing the amount of humic acid, electrical conductivity (13.71%) decreased but organic carbon (82.88%), nitrogen (55%), phosphorus (75.93%), potassium (23.97%), calcium (46.35%) and magnesium (58.82%) showed a significant increase and the highest amount of these properties was obtained in the highest amount of humic acid consumption. The interaction of humic acid type and its amount on the amount of organic carbon, phosphorus, potassium, calcium and magnesium in the soil was significant and the highest amount of calcium (57.03%) was obtained from the application of 60 liters per hectare of Humax. The highest leaf nitrogen concentrations were obtained from the application of liquid Humax (MAX:42.23%), liquid of Shimi Gol, solid Ferti Plus and ordinary solid ShimiGol, respectively. The highest concentrations of phosphorus (17.65%) and magnesium (16.96%) were obtained from Humax and the highest concentrations of calcium were obtained from three solid humic acids, Ferti Plus, liquid of ShimiGol and liquid of Humax with a significant difference with ordinary solid. The type of humic acid consumed was not significant on any of the yield components (weight of 100 grains (21.69%), ounces (27.45%) and emptiness percent (25.38%)). The amount of humic acid consumed was significant on all measured characteristics. So that the best yield components and the highest element concentration were obtained from the highest amount of humic acid consumption.Humic acid has direct and indirect effects on plants. Indirect effect is usually in the form of changes in environmental conditions such as modification of soil physical condition, enzymatic and hormonal effects and soil pH, improvement of soil structure, aeration, drainage, water holding capacity, soil temperature and direct effects includes increasing biomass and microbial population, antiviral activity and growth modulation, increasing plant resistance to salinity and drought stress. Humic acid increases nutrient uptake, increases germination and root growth, and improves yield quantitatively and qualitatively. Humic substances also dissolve calcium carbonate in the soil and replace calcium with sodium by activating sulfur oxidizing bacteria, as well as reduction of soil pH to improve nutrient uptake. Humic acid can directly release various elements from minerals, absorb them and deliver them to the roots at the right time. Because humic acid is a valuable source of macro and micro nutrients, it provides a good nutritional balance for the plant and leads to greater absorption of nutrients and specific functional responses in the plant.Conclusion Application of humic acids in liquid or solid form, domestically or externally produced, can increase the supply of nitrogen, potassium, phosphorus, calcium, magnesium, as well as the content of organic carbon in the soil and reduce pH, increase the concentration of elements in leaves and improve yield components. Of course, it should be noted that among the internal humic acids, the solid Ferty Plus, Shimi Gol were as well as Humax liquid. Relying on internal knowledge can prevent unnecessary outflow of currency.
Volume 43 - Issue 3
N Norouzi; shaban ghavami jolandan; M. J Sheikh Davoodi; S.M. Safieddin Ardabili
Abstract
IntroductionToday, with advances in all sciences, we must always look for a way to make the best use of plant residues and turn them into valuable products. A consequence of improving family life standards and consistent industrial development is a higher demand for energy usage. Nowadays, agricultural ...
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IntroductionToday, with advances in all sciences, we must always look for a way to make the best use of plant residues and turn them into valuable products. A consequence of improving family life standards and consistent industrial development is a higher demand for energy usage. Nowadays, agricultural residues are produced in huge quantities and could be considered as a promising source for renewable energy generation. Bagasse is one of the major sources of sugarcane production. The production of valuable products from Bagas, in addition to having economic benefits, can reduce the environmental damage caused by burning them. In recent years, there has been an increasing trend in the utilization of sugarcane bagasse as a major by-product of the sugarcane industry. Another very valuable substance produced from sugarcane bagasse, which we will discuss in this study, is bio compressed coal. Valorization of sugarcane bagasse to engineered biochar using hydrothermal carbonization (HTC) presents a perspective source to substitute conventional fossil fuels. HTC process offers the benefits of converting the sugarcane bagasse into biochar and bio-oil. In this process, biomass is usually conducted in the temperature range of 180–250 ◦C. HTC technique is promoted as one way of reducing carbon dioxide (CO) emissions, which mostly generated through open burning of crop residues. Besides the utilization for power/heat generation for sugarcane industries, Bagasse may find other potential applications, for instance: electricity generation, biogas production, livestock feed/compost production, and also bioethanol production. The unique features of biochar generated through HTC process are its portability, high volumetric energy density, hydrophobicity, and wear ability. Materials and MethodsIn this research, sugarcane waste was obtained from Hakim Farabi Sugarcane Cultivation and Industry Company in Ahvaz. The hydrothermal carbonization process was performed in a batch reactor at Shahid Chamran University of Ahvaz. The parameters studied in this study include the retention time of the material inside the reactor (30, 75, and 120 minutes), bagasse mass to water ratio (0.15, 0.20, and 0.30) and the pressure inside the reactor (10, 12.5 And 15 bar). In order to measure the pressure, a Nuova FiMa barometer was used, which was able to measure the pressure values up to 25 bar. A temperature control system model HANYoung ED6 was used, which was equipped with a ceramic heater with a diameter of 230 mm and a height of 230 mm to provide heat for the process. The PARR1266 calorie bomb device was employed to measure the calorific value of the samples. The moisture content of the samples was also measured using ASTM-2010a standard. In this experimental work, the response surface method was employed to investigate the effect of input parameters (i.e., pressure, residence time, and water-to-biomass) on the response parameter (i.e., HHV and energy consumption). Design Expert ver.10 software was used to predict the corresponding models. The obtained models provided a good relationship between the independent/dependent parameters. Results and DiscussionThe HTC process has been analyzed using a Response Surface Method to derive predicted models for the HHV and energy parameters. The results obtained showed that all models provided could successfully predict the HTC process. According to the results, the models developed were statistically significant at the level of 1%. The multi-regression models between the input/response variables were obtained as second-order quadratic equations. The F-value for the residence time, and water-to- bagasse, and pressure were 2417, 286, and 1185, respectively. The value of F-value of each derived model indicates the significance of the studied parameters. The parameters of water-to-bagasse and pressure had a more significant effect compared to the residence time factor. The R-square value for this study was achieved as 0.0996, indicating that the proposed model was able to evaluate the experimental data thoroughly. A multi-objective optimization technique was used to achieve an optimal HTC process condition with the maximum possible amount of desirability value. ConclusionThe optimum amount of water-to-bagasse, pressure, and residence time was calculated using the response surface techniques. A pressure of 11 bar, the residence time of 38 min, and water-to-bagasse of 0.15 were found to be optimal values. The findings of this study indicate that at optimal input variables, the value of calorific value and used energy was 21 Mj/kg and 0.09 kWh, respectively. Keywords: Hydrothermal carbonization, Sugarcane bagasse, Response surface method, Optimization
Volume 45 - Issue 4
Plant Nutrition, Soil Fertility and Fertilizers
Nadieh Dastbaz; Mohammad Ali Mahmoodi; Akbar Karimi; Sara Salavati
Abstract
Introduction Nitrogen (N), an essential nutrient for growth and development of plants, is added to agricultural fields to boost crop yields. Major concern in modern agriculture to account for maximum nutrient use efficiency, improve the soil fertility and prevent groundwater pollution. Environmental ...
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Introduction Nitrogen (N), an essential nutrient for growth and development of plants, is added to agricultural fields to boost crop yields. Major concern in modern agriculture to account for maximum nutrient use efficiency, improve the soil fertility and prevent groundwater pollution. Environmental and economic challenges due to nitrogen application in agricultural have increased regard to nitrogen use efficiency (NUE). Improving the nitrogen use efficiency, which is the fraction of the applied fertilizer nitrogen taken up by a plant for its physiological and growth purposes, is one of the strategies for reducing N loss in agriculture. With the continued escalating costs of inorganic fertilizers, NUE in field crops should be enhanced to reduce production costs. Therefore, it is essential that appropriate N fertilizer management practices are adopted to optimize the use of applied N in cropping systems. NUE and better plant growth are related to soil’s physico-chemical traits. In this context, the application of soil amendments, such as zeolie, has great importance for the reclamation of soil properties and improve plant growth. Natural zeolites are naturally occurring, hydrated aluminosilicates with and being considered as good soil amendment for minimizes N losses and increase NUE. Therefore the objective of this study was investigating the effect of different levels of clinoptilolite zeolite and nitrogen fertilizer on the efficiency of nitrogen use, growth and yield of maize (Zea mays L.) in field conditions. Materials and methods This study carried out in field condition as a split-plot arrangement based on randomized complete blocks and in three replications, at the University of Kurdistan research farm in Dehgolan. The experimental treatments include the application of clinoptilolite zeolite at four levels (0, 5, 10 and 15 ton ha-1) as the main plot and the application of nitrogen at five levels (0, 50, 100, 150 and 200 kg N ha-1) as the sub-plot. Urea fertilizer was used to supply the required nitrogen.Maize cultivation (KSC 260 cultivar) was done in 2021. At the end of cultivation season, harvest was done from each plot, and some plant growth traits (leaf area, cob length and cob diameter), leaf N concentration, yield components (grain number in cob, raw number in cob and grain weight in cob), and grain yield were measured. In addition, the NUE was calculated. In order to investigate the effect of zeolite on soil nitrogen status, soil samples were collected from plots after harvest, and cation exchange capacity (CEC), and total soil nitrogen (TN) were measured. Analysis of variance (ANOVA) was performed using SAS program version 9.4 (SAS Institute, Cary, NC). Significant differences of the mean values (P <0 .05 for F-test) were determined by Duncans’s Multiple Range test. Results and Discussion The results showed that as a result of the application of 10 and 15 ton zeolite ha-1, the soil cation exchange capacity the soil total nitrogen concentration, leaf nitrogen concentration, leaf area index ,cob length, grain yield and nitrogen use efficiency increased significantly. The results showed that the highest leaf N concentration, plant growth indices, grain yield and yield omponents was observed in the treatments of co-application of 150 and 200 kg N ha-1 with 10 and 15 ton ha-1 of zeolite. There was no significant difference between the grain yields in these treatments. The results also indicated that Moreover, nitrogen use efficiency decreased with increasing nitrogen application levels. The nitrogen use efficiency (NUE) in the 150 kg N ha-1 treatment was significantly higher than 200 kg N ha-1 treatment. The results demonstrated that there was no significant difference between two nitrogen fertilizer levels (150 and 200 kg N ha-1) positive effects on grain yield. The improved maize growth and enhanced grain yield induced by zeolite amendment were related to the increase in soil CEC, soil N status, N uptake in plant, as well as probably improved soil nutrient availability and physicochemical propertis. Leaf N concentration (56.6), leaf area index (56.5%), cob length (21.5%), leaf nitrogen concentration (56.6%), grain weight in cob (61.8%), grain number in cob (41.6%) and grain yield (38.6%) in the plant were significantly higher than control treatment. Conclusion It could be concluded that application of potassium sulfate fertilizer results In general, it can be concluded that the combined use of zeolite (at the level of 10 ton ha-1) and nitrogen (150 kg ha-1) can be a suitable solution for improving corn yield and increasing the nitrogen use efficiency (NUE).
Volume 44 - Issue 4
Asieh Naroie; Javad Zamani; Shapour Kohestani; Farideh Abbaszadeh Afshar
Abstract
Introduction: The application of biochar in soil as a method for disposal of organic wastes from environment has been considered by environmental scientists in recent years, due to the unique properties of these components. Biochar is a carbon-rich compound that is produced by burning different types ...
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Introduction: The application of biochar in soil as a method for disposal of organic wastes from environment has been considered by environmental scientists in recent years, due to the unique properties of these components. Biochar is a carbon-rich compound that is produced by burning different types of organic wastes under anaerobic or limited supply of oxygen, which called pyrolysis. Biochar due to its physicochemical properties such as porous structure, expanded specific surface area, high organic carbon content, active functional groups, and also high cation-exchange capacity could able to stabilize organic and mineral compounds. Many studies showed that the biochars enhance soil fertility and improve plant growth but if we want to recommend or apply a specific biochar as an amendment of soil, it's necessary to know about the effects of this biochar on the soil properties and growth of plant. So, the aim of this study was to find out the effect of two biochar (biochar of Date Palm's Leaves (DPL biochar) and biochar of Pistchio Harvesting wastes (PW biochar)) on the growth and heavy metals concentrations of Maize (Zea mays L.) under two different soil textures (Sandy and Sandy Loam).Materials and Methods: This study was conducted in a greenhouse condition on the growth of maize in two types of soil (Sandy and Sandy Loam) with application of 5 levels (0, 1, 2, 3 and 5% w/w) of two different types of biocahr (DPL biochar and PW biochar). Maize were cultivated in treatments for 38 days and at harvesting the shoot and root dry weight and shoot height were measured. Also, the concentration of heavy metals (including Fe, Zn, Cu, Mn, Ni, Pb, and Cd) in plant shoots were evaluated.Results and Discussion: The result showed that the growth of maize severely decreased due to the application of the biochar and the negative effect of PW biochar was more than DPL biochar. Meanwhile, the negative effect of PW biochar on plant growth in sandy soil was more than other one (i.e. Sandy Loam soil), which medium (2 and 3% w/w) and high (5% w/w) levels of this biochar caused the plant to stop growing. Also application of 5% of DPL biochar in Sandy Loam soil caused in a decrease of about 19, 69 and 72% in plant height, shoot dry weight and root dry weight of maize in compared with control (without biochar application in this soil), respectively and these ratios were about 15, 44 and 31% with application of 3% DPL biochar; while with application of 3% of PW biochar in sandy loam soil has decreased plant height, shoot dry weight and root dry weight of maize about 17, 53 and 37%, in compared to control respectively. These results approved the greater negative effect of PW biochar on plant growth. Assessment of soil salinity as the application of different levels of biochars showed that these materials increased salinity and thus had a negative effect on plant growth. In overall, the results of this study showed that the use of different biochars have different effects on plant growth, since most of biochars have high salinity, coarse-textured soils could more affected by salinity, because of the lower water holding capacity of this soils. Since, biochar is a stable substance, the results of the concentration of elements in the shoot of plants showed that the concentration of most elements not significantly affected by the application of biochar, however the increase in Fe concentration in sandy soil due to application of PW biochar, also Mn uptake in the effect of applying 1% of DPL biochar was observed. On the other hand, the results of this part of the research showed that DPL biochar at higher levels has even reduced the concentration of Mn in the plant. The results of this section also showed that the application of biochar in sandy loam soil, although it was significant on the concentration of heavy metals Pb and Cd in the plant and had slightly increased them, but their concentration was less than critical levels (dangerous) for human health.Conclusion: The effect of biochar on improving plant growth can be greatly influenced by the combined effect of biochar properties and soil conditions. The results showed that despite the many benefits of the soil application of biochar in the different scientific literatures, it is necessary to study the effect of biochar on soil properties and plant growth before applying any type of biochar in the soil.
Volume 43 - Issue 4
Somayeh Torktaz; Ali Mohammad Borghaee; Jafar Massah
Abstract
Introduction :Robots are suitable for doing things that are tedious, difficult or dangerous to humans. One of the recent applications of robots is to perform various operations in the agricultural sector. The limitations in human resources and the demand for higher efficiency per unit area has made it ...
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Introduction :Robots are suitable for doing things that are tedious, difficult or dangerous to humans. One of the recent applications of robots is to perform various operations in the agricultural sector. The limitations in human resources and the demand for higher efficiency per unit area has made it necessary to use robots in agriculture. In the study, a robot spraying manipulator based on the Stewart mechanism was designed and constructed to perform spraying operations inside the greenhouse with the help of a manual end effector (mechanical robotic arm). In general, manually applied spraying does not spread evenly on all plants, resulting in increased toxic waste, there are also spraying labor costs in this method, so it is not economically viable. Hand spraying is a problem caused by direct contact with the toxin, which puts people in direct contact with chemicals at greater risk for a variety of diseases. Therefore, most of the toxic chemicals used to overcome weeds are a threat to humans and the environment. By poisoning the skin, mouth or breathing can be highly toxic.Materials and Methods: The end effector sprayer is based on Stewart's mechanism and by using six degrees of freedom, allowing nozzles to spray at different angles on plants. For this purpose, six step motors were used to provide the rotational force of the operator's end effectors, which was launched with the Arduino system. In order to supply electrical energy, operator's end effectors and Arduino devices utilized a 500-watt computer power supply, calculating the dynamics and reverse kinematics of the Stewart platform, we specified unique codes for its rotation. In this study, inverse kinematics was used to obtain the position of the joints by knowing the position of the center the moving platform and connecting the connectors to the moving platform by the hinge joints, and to the actuators arm by the spherical joint. The dynamics of the actuator, the movement of the moving platform by the actuators was calculated. In this method, the direction of the moving platform the step motors are driven a time by the microcontroller in pairwise manner. Using arms and linkers, stepper motors could move the platform in three different angles. Due to the angle and radius of the arm's, the moving platform has an angle of 18 degrees to the horizon, which makes it able to spray directly into the target plant and make a same coating. Also the velocity and acceleration of the moving platform movement were calculated according to the rotational speed of the stepper motors the maximum velocity and linear acceleration of the moving platform are calculated 141 mm / s and 244mm/s2 respectively. Results and Discussion: In order to accurately evaluate the performance of the sprayer, laboratory experiments were carried out to verify the performance of the control system and determine the height of spraying at different intervals. The end effector nozzle height was 117 cm above the ground, and the moving platform end effector with zero degree angle, and 18 degree spraying. It was determined that at a distance of 0.5 m 1 m and 1.5 m from the nozzle, the spraying heights were 100 cm, 57.7 cm and 12 cm accordingly. Based on this evaluation, spraying operation which was carried out at a distance of 0.5 m from the nozzle could reach highest level of spraying height. Finally, after modeling the end effector with solidworks software, it was simulated in the Adams software environment and by transferring the model to Adams, the force applied to the moving platform by the actuators, the velocity and acceleration of the moving platform were investigated. In the simulation, the applied force was evaluated by a pair of actuators on the moving platform, with the software output predicting the applied force correctly. In examining the linear velocity of the moving platform, the software output was about 5 cm/s more than the actual value and also in the simulation of linear platform moving acceleration, the software output was equal to the calculated value.Conclusion: According to studies, this is the first time that the platform has been used in robotic sprinklers, and could be a reference for further research in the field due to its innovation. This end effector had no singularity at an angle of 0 to 18 degrees and in both directions, spraying had a 10% difference in spraying. According to the simulation results performed with Adams software, the amount of force applied by the propellers was linear on the moving platform. Moreover, according to the simulation results with the aforementioned software, the acceleration changes of the moving platform were also linear.
Volume 35 - Issue 1
A. Gholipour; M. Ghajar Sepanlou; M. A. Bahmanyar
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 37 - Issue 1
Soil Chemistry and Pollution
Roya Zalaghi; Ali Akbar Safari Sinegani
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 49-65
Abstract
Phytoremediation, a relatively new and an environmentally friendly technology, is the use of plants for the removal of pollutants from contaminated soils. A greenhouse pot experiment was conducted to evaluate the heavy metal (lead, zinc and copper) accumulation of Zea mays, Helianthus annuus, Cannabis ...
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Phytoremediation, a relatively new and an environmentally friendly technology, is the use of plants for the removal of pollutants from contaminated soils. A greenhouse pot experiment was conducted to evaluate the heavy metal (lead, zinc and copper) accumulation of Zea mays, Helianthus annuus, Cannabis sativa and Brassica napus. Plants were grown in two soils; one from Ahangaran Lead-Zinc Mine, and the other from an agricultural soil. The shoot and root dry weight, heavy metal concentrations in shoot and root, translocation factor (TF), Enrichment factor (EF) and heavy metal fractions were measured. The distribution of different lead and zinc fractions were revealed the following order: residual > carbonate > organic > exchangeable. However, for copper the order was as residual > organic > carbonate > exchangeable. The minimum lead concentration (25.50 mg kg-1) was observed in Z. mays shoot tissue and the maximum (301.30 mg kg-1) in C. sativa shoot tissue. Lead TF ranged from 0.72 to 0.96 and decreased in the following order: H. annus > C. sativa > B. napus > Z. mays. Zinc TF changed from 0.70 to 0.99 and as H. annus > Z. mays> C. sativa > B. napus, and copper TF turned from 0.49 to 1.83 and as H. annus > C. sativa > B. napus > Z. mays. The EF value of lead varied from 0.24 for Z. mays to 0.48 for C. sativa, from 0.75 for Z. mays to 1.01 for H. annus regarding to zinc, and the copper EF value ranged from 0.39 for C. sativa to 1.42 in H. annus. Although H. annus and C. sativa accumulated lead more than Z. mays and B. napus, none of the plants was hyperaccumulator for lead, zinc or copper.
Volume 32 - Issue 1
M. Yari; N. Khadwmol Hosseini
Volume 36 - Issue 1
Farshid Esmaeili; Sepideh Kalate Jari; Zarintaj Alipour
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 51-65
Abstract
It seems necessary to study different beds on which pot plants can be grown in apartments. Organic wastes and different types of mineral substances can be used to prepare domestic beds as cheaper, more available, and higher-quality alternatives for foreign and imported beds. For this purpose, the present ...
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It seems necessary to study different beds on which pot plants can be grown in apartments. Organic wastes and different types of mineral substances can be used to prepare domestic beds as cheaper, more available, and higher-quality alternatives for foreign and imported beds. For this purpose, the present study explores effects of different organic and inorganic beds on the pot plant Dracaena marginata Ait and its ornamental leaves. The beds used for growing the plant in this study included different ratios of peat, urban waste compost, and vermicompost in combination with perlite and zeolite. Findings indicated that the beds composed of peat (50%) + perlite (50%), waste compost (50%) + perlite (50%), and vermicompost (50%) + perlite (25%) + zeolite (25%) are the most effective ones on plant altitude, number of leaves, and stem diameter while the poorest results were obtained for a combination of waste compost (50%) + perlite (25%) + zeolite (25%). The highest level of absorption for nitrogen, phosphor, and potassium was observed in the treatment peat (50%) + perlite (50%) while the lowest absorption was found in the plants treated with waste compost (50%) + perlite (25%) + zeolite (25%). Given these results, and due to the lower cost and availability of urban waste composts and vermicompost compared to peat, the combination of vermicompost (50%) + perlite (25%) + zeolite (25%) as well as waste compost (50%) + perlite (50%) can be used to replace the imported products (i.e. peat (50%) + perlite (50%)) in growing Dracaena marginata Ait and other ornamental or pot plants in our country.
Volume 33 - Issue 1
Volume 35 - Issue 2
Safoura Jafari; Mostafa Chorom; Naeimeh Enayatizamir; Hossein Motamedi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 55-70
Abstract
Soil salinity induces a stressful environment for soil micro-organisms and reduces their number and activity. The objective of this research is investigating the effect of different levels of salinity on some of soil biological indicators and also assessing the effect of two types of halotolerant rhizospheric ...
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Soil salinity induces a stressful environment for soil micro-organisms and reduces their number and activity. The objective of this research is investigating the effect of different levels of salinity on some of soil biological indicators and also assessing the effect of two types of halotolerant rhizospheric bacteria on the value of these indexes in soil. 35 strains were isolated from saline rhizospheric soils and their ability to grow in concentrations of 0 to 600 mM salt was evaluated. Among them, two isolates were identified as salt tolerant bacteria that were recognized as genera of Bacillus subtilis and Corynebacterium glutamicum. The factorial experiment, as the completely randomized design, was performed with two factors including salinity in four levels (2, 4, 8 and 12 dS/m) and bacteria in three levels (none inoculated, inoculated with Bacillus subtilis and inoculated with Corynebacterium glutamicum) in the greenhouse. The cultivated plant was barley. Different levels of salinity in soil were created by adding the mixture of salts including NaCl, CaCl2 and MgCl2. After 8 weeks, the amount of soil respiration, microbial biomass carbon and qCO2 were measured in the soil. The results of the statistical analysis showed that the effect of salinity levels on these indicators were significant (P<0.001). Bacterial inoculation in different levels of salinity, significantly, increased the soil respiration (P<0.05) and microbial biomass carbon (P<0.001) and reduced qCO2 (P<0.001) in soil. The results of this research showed that the halotolerant rhizospheric bacteria reduced the negative effects of salinity on soil microbial indicators.
Volume 34 - Issue 2
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 55-68
Abstract
Pesticides application can be leached to ground water or throughout runoff reach to water surface. The adsorption behavior of the river sediment with the pesticides has a significant influence on the environmental quality of a river. The objective of this research was to study the sorption isotherms ...
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Pesticides application can be leached to ground water or throughout runoff reach to water surface. The adsorption behavior of the river sediment with the pesticides has a significant influence on the environmental quality of a river. The objective of this research was to study the sorption isotherms of lindane pesticide on sediments of Ahvaz fifth bridge, Darkhoin and Khorramshahr hydrometric stations in two low water and high water seasons. Also, the effect of some chemical and physical properties on adsorption capability of sediments was investigated. The water and sediment samples used in this research were collected from downstream of the Karoon River. The results showed the salinity of water and sediments of the river in both seasons increased from Ahvaz to Khorramshahr. The highest percentages of OM and clay were 2.45 and 30.8, respectively, for Darkhoin and the lowest were 0.49 and 2.1 for Ahvaz fifth bridge station. The kf value of Lindane for Darkhoin sediments (195.5 mg/kg) was found to be highest and the lowest kf value (81.5 mg/kg) was observed in Ahvaz fifth bridge station. Langmuir b value for lindane was found to be 340 and 140 mg/kg for Darkhoin and Ahvaz fifth bridge station, respectively. Significant correlation was found between clay and organic matter percentage of sediments and amount of lindane adsorption.
Volume 39 - Issue 2
Z Zeynoldini; M Karami; A Fatemia Ghomsheh; P Shekaari; F. Hamedi
Volume 41 - Issue 3
Soil Physics, Erosion and Conservation
Ruhollah Rezaei Arshad; M Mahmudabadi; Mohammad Hady Farpoor; Majid Fekri
Abstract
Introduction Under natural conditions, intensive and erosive storms commonly associate with high-speed winds. In fact, wind velocity affects water erosion rate through enforcing falling drops and enhancing rainfall erosivity. Therefore, knowledge of interaction between wind and rain as erosive agents ...
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Introduction Under natural conditions, intensive and erosive storms commonly associate with high-speed winds. In fact, wind velocity affects water erosion rate through enforcing falling drops and enhancing rainfall erosivity. Therefore, knowledge of interaction between wind and rain as erosive agents on interrill erosion is of prime importance. However, no comprehensive study has been done on this topic under controlled laboratory conditions. This study was conducted to investigate interrill erosion affected by different rain intensities and wind velocities on several soils with different aggregate size distributions using the Simultaneous Wind-Rainfall-Runoff Simulator (SWRRS). For this purpose, a multisystem was constructed for the first time in Iran to investigate the simultaneous effects of wind and rain erosivity agents on soil erosion under laboratory conditions. Materials and Methods The simulator was calibrated in two cases. First, the intensity and uniformity of the simulated rains were assessed for each nozzle, separately. Second, the calibration procedure was performed for different combinations of the selected nozzles to achieve the best performance. For each case, different water pressures were generated to introduce several water discharges and make initial raindrop velocities. Afterwards, the interrill erosion experiment was done using four constant wind speeds including 0, 6, 9 and 12 m s-1at the height of 40 cm which were applied in combination with three rain intensities of 30, 50 and 75 mm h-1 on three soil samples with different aggregate size distributions (D2mm, D4.75mm and D8mm). Each treatment was conducted at three replicates under laboratory controlled conditions. By using different wind speeds, rain intensities and soil aggregate sizes, interrill erosion rate was measured under steady state conditions. Results and Discussion Results showed that wind velocity has a significant effect on interrill erosion rate and the interaction between wind and rain on interrill erosion was significant, as well. Although, there was no significant difference between the erosion rate at wind velocity of 0 and 6 m s-1, the wind velocity of 9 and 12 m s-1 showed significant difference with and higher erosion rates than the velocity of 6 m s-1. The mean erosion rate at wind velocities of 0, 6, 9, 12 m s-1 was 0.43 × 10-4, 0.54 × 10-4, 0.97 × 10-4 and 1.46 × 10-4 kg m-2 s-1, respectively. With increasing rain intensity from 30 to 75 mm h-1, the erosion rate increased from 0.52 × 10-4 to 1.16 × 10-4 kg m-2 s-1. On average, the erosion rate of the soil containing larges aggregates i.e. D8mm (0.73 × 10-4 kg m-2 s-1) was less than that with the finest aggregates i.e. D2mm (0.99 × 10-4 kg m-2 s-1). The findings of this study highlighted the importance and necessity of more attention to wind speed particularly those velocities faster than a threshold velocity in the study of interrill erosion. Conclusion In arid and semi-arid regions such as most parts of Iran, rainstorms are usually accompanied by strong winds. Despite the undeniable influence of wind on the erosive power of rain, a host of research has investigated water and wind erosion processes, separately. Therefore, this study was done to investigate the simultaneous effect of wind velocity and rain intensity on interrill erosion rate in three soil samples. The results indicated that wind velocity has a remarkable influence on interrill erosion rate due to wind-driven rain. Wind velocities faster than 6 m s-1 increased interrill soil erosion rate, particularly those combined with higher rain intensities. This is due to an increase in the velocity of falling raindrops on the soil surface which results in greater kinetic energy. Also, the findings showed that the soil containing coarser aggregates due to greater random roughness exhibited less sensitivity and interrill erosion rates as compared with the soil having finer aggregates, especially at faster wind velocities. The rate of interrill erosion in soil D2mm was 1.35 times higher than soil D8mm indicating the importance of random roughness. In addition, there was no significant difference between the measured erosion rates at wind speeds of 0 and 6 m s-1, in all cases. However, with increasing wind speed from 6 to 9 and also to 12 m s-1, significant increases in soil erosion rates were observed. Accordingly, a threshold wind velocity can be considered in wind-driven interrill erosion. The findings of the present study can be applied for better understanding and modeling of water and wind erosion mechanisms and dominant processes.
Volume 42 - Issue 4
N. Yaghmaeian Mahabadi; N. Nobahar Deylami; M. Rahimi Mashkaleh; A. Fatemi Chookami
Abstract
Introduction As one of the pedogenic factors, topography can be an important and effective factor on yield and quality of crop performance through affecting water distribution and soil properties in different landscape positions. This factor affects soil properties by changing the altitude, steepness ...
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Introduction As one of the pedogenic factors, topography can be an important and effective factor on yield and quality of crop performance through affecting water distribution and soil properties in different landscape positions. This factor affects soil properties by changing the altitude, steepness and slope direction of lands. Understanding the soil limiting factors for the production of crop would help policy makers for the sustainable planning and management of the soils. Among many landscape parameters, effect of slope position and aspect on the variability of soil quality attributes and yield were little studied. This study aims to investigate the effect of topography on soil properties, yield and quality of tea in Lahijan, Guilan province. Materials and Methods Four slope positions were selected from one transect in the northern slope and one transect in the southern slope of tea gardens in Lahijan, Guilan province. In each slope position, one profile was drilled. Soil samples (0 to 30 cm depth) and green tea leaves were collected from in three plots (2 m2) around each profile. Physicochemical soil properties, yield and quality of tea were determined according to standard methods. So, this study was carried out in a factorial arrangement based on the completely randomized design with two factors, including slope position (summit, shoulder, backslope and toeslope) and slope aspect (northern and southern) with four replications. The data were analyzed by using SAS and graphs were plotted with the help of Excel program. Qualitative land suitability was also determined using simple limitation and parametric methods for tea production in this hilly region. Results and Discussion The results showed that slope position significantly affected some soil physical and chemical properties including silt content, electrical conductivity, total nitrogen, organic matter, available potassium and phosphorus. The highest content of organic matter, nitrogen and phosphorus in the soil of toeslope position can be attributed to soil erosion and transferred from top of the slope and their accumulation in this situation. The highest values of clay was found in the in the northern-toeslope position. The saturated water content in soil of the northern aspect was significantly higher than the southern aspect. The analysis of data showed that the interaction effect of slope positions and aspects on the yield and qualitative characteristics of tea, including the theaflavin, thearubigin, total color and brightness was statistically significant. Yield was the highest (3112 kg/ha) and the lowest (1762 kg/ha) in the northern-toeslope and southern-shoulder positions, respectively. The highest amount of theaflavin, thearubigin, total color and brightness were related to the northern-toeslope position. The northern aspect of all slope positions had more yield than the southern aspect that have contributed to higher amount of organic matter and saturated water content in northern aspect. Correlation analysis revealed that tea yield, thearubigin and brightness were significantly positively correlated with soil organic matter (P value < 0.05) also tea yield, theaeflavin and total color positively correlated with soil nitrogen (P value < 0.05). Also, theaflavin was significantly and positively correlated with thearubigin (P value < 0.05). This correlation is probably due to the presence of common chemical precursors for the formation of two substances as well as the transformation of theaflavin to thearubigin as one of the path for the thearubigin formation. According to the land suitability evaluation, the climatic factors especially the minimum temperature during the coldest month of the year is the most important limiting factor for tea cultivation in the study area. Another limiting factor was related to the topography (slope), which caused the lowest suitability class (N) in the shoulder and backslope positions. Conclusion Overall, the results showed that higher soil quality in northern-toeslope aspect lead to an increase in yield and quality of tea. The correlation results showed that soil nitrogen and organic matter are two important and effective parameters on the yield and quality of tea. This findings showed that the need to consider physiological characteristics of specific variety and the soil moisture and nutrients status in requirements tables for tea cultivation. Investigations on the soil-landscape relationship revealed that there is a strong link between the soil properties and the slope positions and aspects. More detailed studies would be helpful for the management of the sloping geomorphic surfaces.
Volume 33 - Issue 2
Volume 34 - Issue 1
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 57-64
Abstract
Persian lilac fruit is an inedible fruit that contains oil seeds which can be used for industrial purposes. Dehulling is a primary step which must be done on the fruit before extracting oil from them. In this research, the process of dehulling Persian lilac fruits by sodium hydroxide was investigated ...
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Persian lilac fruit is an inedible fruit that contains oil seeds which can be used for industrial purposes. Dehulling is a primary step which must be done on the fruit before extracting oil from them. In this research, the process of dehulling Persian lilac fruits by sodium hydroxide was investigated in two, stages, using completely randomized design method. In the first stage, the effect of 6, 9, 12 and 15% (w/w) concentration at 90°C on the duration of dehulling was studied. In the second stage, the effect of solution temperature at 25, 40, 70 and 80°C with 6% (w/w) concentration on the peeling duration was investigated. The results indicated that increasing the concentration of the solution from 6 to 15% left no major impact on drying duration, but the duration significantly decreased by increasing the temperature of the solution. The dehulling durations were 33 h and 20 min, 18 h, 2 h and 30 min and 1 h and 25 min for 25, 40, 70 and 80°C, respectively. The experiment indicated that increase of the dehulling time was positively related to the light diffraction of the solution. A model for predicting the level of light diffraction as a function of the dehulling time and another model for stating the remaining time of dehulling process as a function of light diffraction of the solution were proposed. Both models were highly fitted to the experimental data (R2>0.96).
Volume 41 - Issue 1
Soil Biology, Biochemistry and Biotechnology
Naeimeh Enayatizamir; A Moezzi; Shila Khajavi
Abstract
Introduction Biosurfactants or microbial surfactants are surface active molecules that are produced from a variety of microorganisms. Due to its amphiphilic nature, these biomolecules are capable of lowering the surface tension, interfacial tension and forming micro-emulsion to enable mixing of two immiscible ...
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Introduction Biosurfactants or microbial surfactants are surface active molecules that are produced from a variety of microorganisms. Due to its amphiphilic nature, these biomolecules are capable of lowering the surface tension, interfacial tension and forming micro-emulsion to enable mixing of two immiscible solutions. Such properties exhibit excellent detergency, emulsifying, foaming and dispersing traits, which can be applied in various industries. The features that make them commercially promising alternatives to chemically synthesized surfactants are their lower toxicity, higher biodegradability, better foaming properties, and greater stability towards temperature and pH. Limited full scale production has been realized for many biosurfactants due to expensive raw material, low production yield and high purification cost. In order to alleviate these problems, many studies have been carried out using cost-free or low-cost feed stocks or agricultural byproducts as substrates for biosurfactant production. Oil pollution and remediation technology has become a global phenomenon of increasing importance. Materials and Methods In this study, Potential strains of microorganism were isolated from various hydrocarbon polluted area on nutrient agar medium using sterile saline (0.85% NaCl) method and different bacterial isolates were selected based on the colony morphology on nutrient agar. The selected isolates were screened for the production of biosurfactants using following screening methods. Pure culture of bacterial isolates were streaked on the freshly prepared blood agar and incubated at 37°C for 48-72 h. Results were recorded based on the type of clear zone observed i.e. α-hemolysis when the colony was surrounded by greenish zone, β-hemolysis when the colony was surrounded by a clear white zone and γ-hemolysis when there was no change in the medium surrounding the colony. Surface tension reduction and emulsification index of isolates was determined by culturing the isolates in minimal mineral salt solution containing glucose as carbon source. Based on the screening test results, the positive isolates were inoculated into the mineral salt medium for the biosurfactant production and then identified by its microscopic appearance, biochemical tests based on Bergey’s manual of determinative bacteriology and molecular method. Bio-surfactant production by superior isolate was evaluated in minimal mineral salt medium containing different carbon sources (kerosene, sugar cane molasses, phenanthrane and glucose) at 30 and 37 °C within the incubation periods of 48 and 156 hours. Emulsification activity, oil spreading, drop collapse, cell hydrophobicity and surface tension activity of isolate were used to detect biosurfactant production. Results and Discussion Out of 13 isolates of microorganism, strain S10 showed positive response to biosurfactant tests (hemolytic activity, surface tension reduction and emulsification index) and was select for identification and considering the effect of different carbon sources on its biosurfactant production. The biochemical and molecular identification results showed isolate S10 belongs to Bacillus pumilus. Results showed that Bacillus pumilus was able to grow in all carbon sources. Based on bio-surfactant production, this strain had a positive or β hemolysis on blood agar medium. Results showed that this bacterium was able to grow in all carbon sources. The compound produced by this strain in each of carbon sources at both temperatures (30 and 37 °C) and incubation periods (48 and 156 hours) collapsed down. The maximum surface tension reduction was recorded in the samples containing molasses as carbon source incubated at 30 ° C for 48 hours, in which bacterium reduced surface tension to 20.33 mNm-1. The highest bacterial growth with a higher surface tension reduction selected this isolate as a potential biosurfactant producing microorganism. The maximum emulsifying and cell hydrophobicity were also recorded in molasses (28%) and kerosene (70%) respectively. Conclusion In conclusion, the study represented surfactant activity of the bacterial strain isolated from oil contaminated soils. This confirms that environment has an influence on the metabolism of the tested microbes. This study suggests that, Bacillus pumilus isolated from oil contaminated soil showed biosurfactant producing ability. Further study on the utilization of agro industrial wastes as substrates for the large-scale production of biosurfactants is recommended.
Volume 36 - Issue 2
Abbas Rohani; Hasan Masoudi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 59-68
Abstract
Replacement of tractors is a very difficult task. Farm managers often need to make such economic decisions about their machines. Repair and maintenance expenditures can have significant impacts on these economic decisions and forecasts. The purpose of this research was to identify a regression model ...
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Replacement of tractors is a very difficult task. Farm managers often need to make such economic decisions about their machines. Repair and maintenance expenditures can have significant impacts on these economic decisions and forecasts. The purpose of this research was to identify a regression model that can determine economic life of two-wheel drive tractors. The study was conducted using empirical data on 60 two-wheel drive tractors from Astan Ghodse Razavi agro-industry during the years 1988 to 2005. A power model was selected as the best model for prediction of repair and maintenance costs. Based on the power model, the cumulative cost model (CCM) was used to predict the tractors economic life. 29025 hours was predicted as the economic life of the tractor by the CCM model, while according to cost minimization model (CMM) this parameter was equal to 27773 hours.
Volume 37 - Issue 2
Soil Biology, Biochemistry and Biotechnology
M. Soliemanzadeh; H. Khademi; M. Sepehri
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 59-72
Abstract
Microorganisms play an important role in providing nutrients for plants and also in soil development. This study was carried out to investigate the effect of two strains of Bacillus cereus on the release of potassium and iron from micaceous minerals. An experiment was set up with a completely randomized ...
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Microorganisms play an important role in providing nutrients for plants and also in soil development. This study was carried out to investigate the effect of two strains of Bacillus cereus on the release of potassium and iron from micaceous minerals. An experiment was set up with a completely randomized design and factorial arrangement with three replications. Treatments included two types of mineral (phlogopite and muscovite), two strains of bacteria (PTCC 1247 and PTCC 1665), control and eight time periods. The results indicated that released potassium and iron were highly dependent on the strain of bacterium and also the mineral type. Strain PTCC 1665 could release a higher amount of potassium as compared to PTCC 1247. The amount of released iron increased at the beginning of the experiment but decreased and then increased as time passed. In general, the amount of released iron from phlogopite was higher than that from muscovite.
Volume 38 - Issue 1
R Taghizadeh-Mehrjardi1; F Sarmadian; A. A Zolfaghari; A. Jafari
Abstract
Introduction: Cation exchange capacity (CEC) has long been input parameter of many environmental models (Manrique et al., 1991). Added to this, CEC data can give more clear and complete interpretation of soil, plant nutrition process and consequently fertilizer and soil amendment requirements. Laboratory ...
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Introduction: Cation exchange capacity (CEC) has long been input parameter of many environmental models (Manrique et al., 1991). Added to this, CEC data can give more clear and complete interpretation of soil, plant nutrition process and consequently fertilizer and soil amendment requirements. Laboratory analysis is the most accurate method for direct measurement of CEC. However, direct measurement of CEC is difficult, particularly in the soils of arid and semi-arid regions of Iran, due to large amounts of calcium carbonate that makes measuring expensive, laborious, and time-consuming (Amini et al., 2005). It can be an appropriate approach to predict CEC from readily available properties via developing nonparametric or parametric methods (Minasny et al., 1999). Therefore, the objectives of this study were to compare and apply different data mining approches including multi-linear regression (MLR), multi-nonlinear regression (MNR), cascade neural network (CNN), two radial base functions (RBF), multi-layer perceptron neural network (MLP), and adaptive neuro-fuzzy inference system (ANFIS) to estimate cation exchange capacity in different soils of Iran. Materials and Methods: For this purpose, 1770 soil samples were selected from different sites in Iran from which 356 samples were used as the testing data, and the remaining 1414 soils were employed as the training. The soil samples were dried, crushed and passed through a 2 mm sieve to prepare for physical and chemical analyses. The percentages of sand (50 -2000 mμ), silt (2-50 mμ) and clay (<2μm) were determined using the hydrometer method according to USDA soil textural classification system. The soil organic carbon was determined using Walkly-Black method and the CEC was measured by the standard method. Then the data mining techniques (i.e. MLR, MNR, CNN, RBF, MLP, ANFIS) were applied to predict CEC from readily available data (i.e. soil organic carbon and clay percentages). Finally, to compare efficiencies of these techniques, different error criteria including root mean square error (RMSE), mean error (ME), coefficient of determination (R2) and relative improvement (RI) were applied. In the present research, an effort was made to calculate the uncertainty of pedotransfer functions using Monte Carlo technique. Results and Discussion: Statistical analyses indicated the soil organic matter and soil texture have the highest variation. For example, variation of SOM has ranged from 0.01 to 2.94. Investigation of correlation coefficients shows that CEC is more related to the parameters, clay and soil organic matter content. Thus, the parameters, clay, silt, sand and organic carbon content were the input independent variables (readily available properties), and the CEC was an output dependent variable in this study. Root mean square error (RMSE) of linear and nonlinear regression was 4.74 and 4.71 meq 100g-1, respectively. This indicates that both methods are able to properly and equally predict CEC. Nonlinear recession equation increased the accuracy of prediction by 0.6 %. Results show that nonparametric artificial neural networks do not increase the accuracy of prediction CEC, significantly. The best result of neural networks was obtained using MLP. Nonparametric regression tree accuracy was slightly better than artificial neural network methods (4.53 and 4.61 meq 100g-1, respectively). The best method for prediction of CEC was ANFIS (RMSE=4.02 meq 100g-1). The accuracy of prediction using this method was 15 % more than linear regression. Moreover, the ANFIS model on the partitioned data by fuzzy k-means cloud enhances the prediction accuracy up to 26%. Monte Carlo results indicate the highest and lowest uncertainty belongs to MLR and ANFIS models, respectively. Conclusion: In the present research, different data mining techniques were applied to predict CEC in various ranges of soils. The data base related to 1770 soil samples was gathered from all over Iran. Results of the comparison indicate the highest prediction accuracy belongs to ANFIS model. Moreover, partitioning the data base to four groups enhances the accuracy of models. This result confirms that pedotransfer functions are more reliable only on the range of existing data. Overall, our efforts resulted only in R2 of 0.58. This means that soil organic matter and clay percentage could only model the 58% CEC variation. This suggests we should incorporate more input data including kind of clay mineral, percentage of calcium carbonate, gypsum, and etc.
Volume 42 - Issue 1
Soil Chemistry and Pollution
Vafa Bozar; Nafiseh Rang Zan; Habibollah Nadian Qomsheh
Abstract
Introduction Soil quality is very important because of the direct impact on agricultural production and the nutrition of living creatures. The use of urban and industrial wastewaters (as lower quality water for irrigation of plants to reduce raw water consumption) can lead to a gradual accumulation of ...
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Introduction Soil quality is very important because of the direct impact on agricultural production and the nutrition of living creatures. The use of urban and industrial wastewaters (as lower quality water for irrigation of plants to reduce raw water consumption) can lead to a gradual accumulation of some heavy metals in the soil, which can enter the food chain and menace the health of creatures. Due to the high costs of the physical cleaning up methods, it is sometimes more logical to use methods that reduce the effects of contaminants in the environment. Materials and Methods For this purpose, a pot experiment with lettuce and spinach was conducted to investigate the effect of carbon black and hair waste (as adsorbent) on the concentration of cadmium and lead in plants, as well as fresh and dry weight as affected by contaminated water irrigation. Carbon black with defined properties was prepared by the Iranian Carbon Black Company. After collecting the hair waste, all was washed with raw water, diluted acid, and distilled water properly. Then the waste was air dried and ground as much as possible to make it uniform and increase the specific area to cause more reaction between the waste and soil. The waste was applied to the soil at a rate of 3 percent by weight. The carbon black was applied to the soil at the same rate as the hair waste. After preparing the pots, spinach and lettuce were planted in the pots and irrigated with contaminated water and harvested 60 days after sowing. At the end of the pot experiment, some growth parameters, as well as the uptake of some elements, including micronutrients and heavy metals, was measured by standard methods. The data were analyzed by using SAS and graphs were plotted with the help of Excel program. So, this study was carried out in a completely randomized design with three treatments, including carbon black (two levels of zero and three percent by weight), hair waste (at two levels of zero and three percent by weight), and irrigation water (at two levels of contaminated water and Non-contaminated) with 3 replications. Results and Discussion The results showed that the use of heavy metal contaminated water significantly reduced the growth parameters in both plants, which was significantly limited by the use of adsorbents, which shows the effect of adsorbents in reducing the negative effects of pollutants in the environment. The analysis of data showed that the effect of carbon black, hair waste, and irrigation water on fresh weight of spinach and lettuce was statistically significant (at the level of 1 and 5%). The interaction effect of carbon black and irrigation water on fresh weight of plants showed that the use of carbon black increased the fresh weight of spinach and lettuce from 16.65 to 19.68 and 11.38 to 16.68, respectively. In the case of treatment of 1.5% carbon +1.5% hair waste, the fresh weight of plants decreased significantly as compared to treatments without hair waste, as well as the control treatment. This can be due to the negative effect of hair waste on the physical properties of soil according to the short time of the research work (2 mounts). More or less, the effect of carbon black and irrigation water on iron, zinc, copper, cadmium, and lead content in both experimented plants was statistically significant. In the case of hair waste effect on iron and lead for spinach, iron and copper for lettuce were statistically significant. The irrigation with contaminated water decreased the amount of iron, zinc, and copper in the aboveground part of plants which is indicating the negative effect of heavy metals in irrigation water on root development and nutrient uptake, as well as competing through antagonistic relationships with micronutrients which are necessary for the plant growth. In the treatments containing 3% carbon black, the number of micronutrients in plants increased significantly due to surface absorption of heavy metal on carbon black and the reduction in the negative effect of heavy metals in soil. In the case of cadmium and lead, the reverse trend was observed. In spinach application of 3% carbon black decreased cadmium and lead content at the rate of 76% and 58%. In the case of hair waste, the effect on lead content at the rate of 25% was significant but for cadmium was not significant. In aboveground parts of lettuce, carbon black reduced cadmium and lead content at the rate of 69% and 54%, respectively. Same as spinach, the effect of hair waste on cadmium content was not significant. The results showed that carbon black had the highest amount of metal adsorption capacity and, therefore, can be more effective than hair waste. Conclusion According to the results, carbon black can be used in the agricultural system which requires more research in the case of its ability.
Volume 42 - Issue 3
M. R. Kamandar; J. Masah; M. Khanali
Abstract
Introduction Now cities are not comparable to the past for many problems such as air and sound pollution of factories and vehicles. Some natural systems such as parks help to keep the stability of cities and improve the life quality of urbanites. Privet with the scientific name of Ligustrum Ovalifolium ...
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Introduction Now cities are not comparable to the past for many problems such as air and sound pollution of factories and vehicles. Some natural systems such as parks help to keep the stability of cities and improve the life quality of urbanites. Privet with the scientific name of Ligustrum Ovalifolium is the evergreen plant, and widely cultivated at all of the parks in Iran. Privet stems are pruned by manual or gasoline -powered hedge trimmer. The knowing of the cutting properties of privet stalk have important role in the design and fabricate of privet pruning machine. A series of laboratory test was conducted to measure the shear force, shear consumption energy and shear strength of stem internodes of privet stalk under quasi-static and impact cutting at different loading rate, different internode position and moisture level 58% wet base. In the quasi-static cutting test, the stalk specimens were cut in the quasi-static process by using a computer aided cutting test apparatus at four loading rates: 5, 10, 15 and 20mm/min and three internode positions: fifth, tenth and fifteenth downward from the terminal bud. In impact test, the stalk specimens were served in impact process by using a cutting test apparatus was designed, fabricated, and calibrated at four loading rates: 1, 2, 3 and 4m/s and three internodes: fifth, tenth and fifteenth. Materials and Methods The study was performed to investigate the effect of quasi-static and impact shear on shear force, shear consumption energy and shear strength. The measured initial moisture content of the samples was 58% on wet base. The privet stalk diameter decreases towards to the top of the plant stalks. Thus, the stalks equally was divided into three regions downward from the terminal bud: (a) fifth internode, (b) tenth internode and (c) fifteenth internode. The quasi-static tests were conducted using the universal testing machine (SMT-5, SANTAM Co, Iran). The shear tests were carried out at four rates of speeds 5, 10, 15 and 20 mm/min. To determine the shear force of privet stalk, an impact cutting tester was designed, fabricated and calibrated. It was similar to an Izod impact cutting tester for metals. A cutting blade with sharpened angel of 23 degree and oblique angle of 60 degree was attached to end of pendulum's arm. The shear tests were carried out at four rates of blade speeds 1, 2, 3 and 4 m/s. A data acquisition system was attached to pendulum arm and it includes 4 strain gages and a digital indicator to show the real-time shear force. Four strain gages were contacted to each other by Wheatstone bridge circuit and were mounted on two sides of pendulum. After calibration, the impact shear force was applied to the privet samples by releasing the pendulum arm in the testing machine up to the sample failure. The real-time applied force and cutting time were measured by data acquisition system and chronometer.Results and Discussion In quasi -static cutting of the stalk specimens, the analysis of variance (ANOVA) indicated that the loading rate and interaction of loading rateinternode position have significant effect on the shear consumption energy and shear strength in probability level of 5% and 1% respectively. However, the effect of internode position on shear force, shear strength and shear consumption energy was significant in 1% probability levels. In impact cutting of the stalk specimens, the analysis of variance showed that, the effect of the loading rate and their interaction of loading rateinternode position on the mentioned parameters were significant (P<0.01) but the effect of internode position on shear force and shear consumption energy was significant in 1% probability levels. The average values of shear force, shear strength and shear consumption energy were deeply decreased with increase in loading rate level from 1 to 4 m/s and internode position from fifteenth internode to fifth internode.Conclusion In quasi-static cutting, the increment proportion of energy consumption at blade velocity of 20mm/min to 5mm/min is about 2.2 at fifth internode, 2.6 at tenth internode and 2.9 at fifteenth internode respectively. Also in quasi-static cutting process, the increment proportion of shear strength at blade velocity of 20 mm/min to 5mm/min is about 1.5 at fifth internode, 1.4 at tenth internode and 1.2 at fifteenth internode respectively.In impact cutting, the reduction proportion of energy consumption at blade velocity of 1m/s to 4m/s is about 1.44 at fifth internode, 1.6 at tenth internode and 3 at fifteenth internode respectively. Also in impact cutting process, the reduction proportion of shear strength at blade velocity of 1m/s to 4m/s is about 5.2 at fifth internode, 29.4 at tenth internode and 53.8 at fifteenth internode respectively.
Volume 43 - Issue 1
Najmeh Asgari hafshejani; shamsollah ayoubi
Abstract
Study of relationship between soil diversity index and soil-landscape evolution in Juneqan plain, Chaharmahal-Va-Bakhtiyari ProvinceABSTRACT ARTICLE HISTORYIntroduction Addressing the concept of soil diversity over landscape as a set of different land units with different spatial distribution, shape, ...
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Study of relationship between soil diversity index and soil-landscape evolution in Juneqan plain, Chaharmahal-Va-Bakhtiyari ProvinceABSTRACT ARTICLE HISTORYIntroduction Addressing the concept of soil diversity over landscape as a set of different land units with different spatial distribution, shape, and arrangement that are affected by natural phenomena and human activities is essential for optimal use, proper management and conservation of this valuable resource. Soil diversity is a criterion for quantifying soil variability that deals with changes in soil properties or classes and understanding of the structure of these changes in the area. Soils evolve continuously under the interactive effects of propulsion and backward pathways, factors, processes, and endogenous and exogenous conditions. In other words, the development of soils is a function of divergent pedogenic pathways (increasing soil evolution followed by increasing soil diversity) and converging (increasing soil evolution and subsequently increasing soil uniformity). In the present study, we investigate the relationships between soil-landscape evolution in a hierarchical sequence of different soil classification and geomorphic levels using diversity indices in some parts of Juneqan plain, Chaharmahal va Bakhtiari province, as an example of semi-arid regions.Materials and Methods The study region with an area of nearby 16000 hectares is located in the Juneqan plain, Charmahal va Bakhtiari Province, Iran, between the coordinates 50° 33ʹ and 50°44ʹE longitude, and 32° 5' and 32°16ʹN latitude. Based on the US Soil Taxonomy (Soil Survey Staff, 2014), the study area has a Mesic soil temperature regime and the soil moisture regime is mainly Xeric and partially Aquic over the study area. A total of 102 soil profiles were dug, described and classified up to the great group level according to US Soil Taxonomy system and soil samples were collected from various genetic horizons. Mountain, hill, piedmont and low lands were the main detected landscapes in the studied area. In order to study the soil evolution the spatial structure of landscape changes, pedodiversity indices were calculated at different taxonomy hierarchical levels (from order to great group in Soil Taxonomy classification) and geomorphic hierarchical levels (landscape, landform, lithology and geomorphic surface) using appropriate indices such as the Shannon diversity index, richness index, Margalef Index, Menhinick Index and O’Neill index.Results and Discussion The soils in the studied area were classified in three main soil orders including Entisols, Inceptisols and Mollisols. The results demonstrated that soil evolution in the studied area was mainly influenced by topography, parent material and locally the underground water level. In the higher lands (like mountain and hills), the lowest evolution was observed whereas, more evolved soils were observed in lower lands with more stable conditions. The results also indicated that all of the pedodiversity indices showed nearby a similar trend and increased under the decrease of the taxonomy and geomorphic hierarchy levels. So that, the minimum diversity was related to order and landscape levels and the maximum diversity was observed in soil great group and geomorphic surfaces levels. Besides, there was a positive linear relationship between species richness index and area of landform units. In other words, as the area of landform units increases, the diversity and consequently the richness index increases. The results also show a positive and nonlinear relationship between number of observations and Shannon entropy index and species richness index.Conclusion The obtained result showed that soil evolution and its properties is affected by some soil formation factors including parent material and topography. In conclusion, it seems, diversity indices are powerful tools in the demonstration of quantitatively soil diversity and provide useful information for soil mapping and optimum soil management purposes. In this study, different soil differentiation indices were calculated and reported for the level of classification hierarchy as well as geomorphic hierarchy. The results showed that by decreasing the level of hierarchy, the dispersion indices increased. This upward trend indicates that the soil evolution is divergent in this region and that as the soil evolves, its dispersal increases. The results also showed that by increasing the area of earthquake surfaces, both species richness index and Shannon entropy index increased. Also, a positive and non-linear relationship was observed between both Shannon entropy indices and species richness indices. Increasing soil richness and dispersion index in geomorphic hierarchy and soil classification as well as increasing richness and Shannon indexes with increasing extent of earthquake surfaces indicate that the soils studied are a nonlinear dynamic system.Keywords: Diversity index, Geomorphology map, Landscape, Landform, Topography.All right reserved. ReceivedReceived in revised formAcceptedKey words:Diversity indexGeomorphology map < br /> LandscapeLandformTopography* Corresponding authorayoubi@cc.iut.ac.ir
Volume 38 - Issue 2
N. Salari Bardsiri; F. Nourbakhsh
Volume 39 - Issue 1
R. Tabatabaekoloor; R. Hadipour
Abstract
Introduction Sugarcane is one of the most important crops for sugar production. Iran produces about 6800 tons of sugarcane from 88000 ha. Sugarcane is subjected to different loading during harvest and postharvest processes. In order to design and modify sugarcane harvesting and processing machines there ...
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Introduction Sugarcane is one of the most important crops for sugar production. Iran produces about 6800 tons of sugarcane from 88000 ha. Sugarcane is subjected to different loading during harvest and postharvest processes. In order to design and modify sugarcane harvesting and processing machines there is a need to study the physical and mechanical properties of crops and their relationship with the machines. Materials and Methods In this study, the experiments were performed on the sugarcane variety of CP48 supplied from Bahnamir city in Mazandaran province, Iran. The physical properties such as moisture content, diameter and linear density were measured. The relationship between linear density and diameter of sugarcane stem was determined on the node and between nodes and also at different heights of stem. Three mechanisms were developed and assembled to a universal testing machine (ASTM50) to measure the shearing, bending and compressing forces of stem. Experiments were conducted on stem samples of 5 cm length. The sugarcane properties in shear, compression and bending were determined using the related equations. All experiments were conducted at three portions of stem (bottom, middle and up) and two points (node and inter nodes). Data were analyzed using a factorial test based on a completely randomized design. Results and Discussion The results of analysis of variance showed that height (bottom, middle and up) and cutting place (on the node and inter nodes) had significant effects on the shear strength and specific shear energy. The shear strength at the bottom and on the node of stem was higher than other parts of stem, but in reverse specific shear energy at the top of stem was higher. The lower parts of stem due to cellular structure and stiff and thick fibers had higher strength. The specific shearing energy at upper portion and on the node was higher than the bending and compression energy at these points. The maximum amount of shear strength was 2.47 Mpa at the bottom of stem and on the node. The specific shear energy was obtained from the area under force-displacement diagram and increased at the upper parts of stem. The maximum and minimum specific shear energy was 56.1 and 41.8 mJ.mm-2, respectively. Analysis of variance showed a significant effect of height and cutting place on the bending stress, bending energy and bending modulus of elasticity for sugarcane stem. The variation range of bending stress from bottom to the top of the stem was 93.4-79.2 Mpa. The bending energy of sugarcane stem was changed from 72.4 to 110.2mJ.mm-2. It was significantly higher in the bottom of the stem than the upper part of the stem. Also, the bending module of elasticity was changed from 721.3 Mpa at the bottom of the stem to 636.7 Mpa at the top of the stem. The effect of height and cutting place on the compressive modulus of elasticity and compressive energy was significant. There was a difference between compressive forces at different parts of stem. The upper parts of stem had less pressure force due to cavity of inter cellular structures. It was 111.3 Mpa at the bottom of the stem and 44.1 Mpa at the top of the stem. The compressive energy at upper parts reduced significantly as the maximum was 215.3 Mpa on the node and the minimum was 84.5 Mpa between nodes. Modulus of elasticity and bending stress at the upper portion and on the node was higher than other points. The same behavior was observed for compressive energy. The compressive modulus of elasticity showed a significant difference at different parts of the stem but there was no meaningful difference between nodes and on the nodes of the stem. Conclusion The results indicated that shear, compressive and bending properties of sugarcane stem were affected by height on the stem. Shear strength was obtained at the range of 1.53-2.47 Mpa at different parts of the stem. The compressive force at the lower parts of the stem was higher than top of the stem. The maximum compressive module of elasticity was 215.3 Mpa on the node and at the bottom of stem. Also, the maximum compressive energy at the bottom of the stem was 111.3 Mpa and at the top of the stem it was 44.1 Mpa. The range of bending stress was obtained from 79.2 to 93.4 Mpa. In general, the results indicated that the lower parts of the stem due to cellular structure and stiff and thick fibers and the nodes due to complex structure and intersection of fibers have more strength than other portions. Therefore, mechanical properties of sugarcane stem are the function of stem structure at different points.
Volume 41 - Issue 4
Micromorphology and Clay mineralogy
masoomeh najafinia; Farhad Khormali; Farshad Kiani; mojtaba Baranimotlagh
Abstract
Introduction Loess sediments of northern Iran represent several cycles of climate change and evolution of the landform for the mid-to-late Quaternary. Climate change in elevations of Iran and its surrounding areas is very controversial in the mid and late Quaternary, and has been discussed in the past ...
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Introduction Loess sediments of northern Iran represent several cycles of climate change and evolution of the landform for the mid-to-late Quaternary. Climate change in elevations of Iran and its surrounding areas is very controversial in the mid and late Quaternary, and has been discussed in the past according to rainfall and rainfall periods and between rainfall, glacial and inter-glacial. Paleomegnatic results also indicate that Early Pliestocene loess (Reddish loess) have accumulated between, 1.8 to 2.4 million years ago. However, pedogenic processes and the effects of past climate in these soils still have not been fully investigated. The loess deposits in northern Iran are a valuable archive of regional paleoclimatic and paleoenvironmental information. Micromorphology is an important technique to identify and interpret the loess- paleosol for paleoclimate studies. Microscopy is a method of studying undisturbed soil samples with the help of microscopic techniques (and sometimes with ultramicroscopic ones), in order to identify their constituents, determine their mutual relations in space and time and interpret their formation conditions. Micromorphology uses these characteristics to make interpretations, generally on the soil formation processes. This study aimed to conduct a micromorphological investigation on the early Pleistocene loess and to compare it with the modern loess derived soils in Agh-Band, Yelli-Badrag and Qareh-Agach in loess plateau of eastern Golestan. Materials and Methods The study area is located in semiarid climate in loess Plateau east Golestan. Six profiles were selected and studied. Physicochemical properties such as soil texture, acidity (pH), electrical conductivity (EC), saturation moisture (SP), organic carbon (OM), cationic exchange capacity (CEC) and calcium carbonate equivalent (CCE) were measured in the laboratory. Then, soil samples were prepared from each horizon for micromorphology studies. For micromorphological studies, thin sections were prepared from undisturbed, oriented and dry clods by standard methods and described under a polarizing optical microscope. Results and Discussion Comparing the results of physicochemical properties (such as color, carbonate percentage, the cation exchange capacity, etc.) in paleosol and modern loess soils indicates that the in paleosols, soil forming processes have passed several stages. The existence of the argillic horizons and the evolved calcic in paleosols and their absence in the modern soils in which they are present, indicates the change in soil formation conditions. The change in the color of paleosols also represents the soil moisture and the more suitable conditions of the past climate (temperature, and especially rainfall) in comparison with the present climate of the region. This color change was due to activation of soil formation processes in paleosols. All paleosol samples had a higher clay content than the late modern loess soils of the Pleistocene, suggesting favorable climatic conditions for soil formation processes and the development of more ancient soil than parent materials. Reducing annual precipitation decrease soil pedogenesis. Conclusion Comparison of the results obtained from paleosols of early Pleistocene with modern soils indicates that the time and climate change caused alterations in the soil micromorphology features (such as the type and amount of pores, soil structure and b-fabric and pedofeatures etc.). One of the most important pedofeatures was clay coating around void, presented only in buried paleosols, which is the evidence for moist climate conditions and subsequently enough leaching for clay translocation. Further, the presence of planar void caused by shrink and swell of clay is evidence for evolution in the paleosols. In argillic horizons of paleosols, dominant b-fabric is speckled due to carbonate leaching while in calcite horizon, it is crystallitic b-fabric. The micromorphological index of soil development calculated, showed that these red-colored deposits are formed under an annual precipitation of about 450- 650mm which represents more humid conditions at the time of their formation than the modern loess soils. In modern soils derived from recent loess, lack of clay coating can be a reason for weakly developed soil formation.
Volume 42 - Issue 2
Post Harvesting Technology
Shamsi Soodmand Moghaddam; Mohammad Sharifi; Hemad Zareiforoush; Hossein Mobli
Abstract
Introduction One of the medical plants is lemon verbena with the scientific name of Lippia citriodora Kunth. It belongs to the family of Verbenaceae. The essential oil of lemon verbena has different compositions, which the most important of them are Geranial, Limonene, and Neral. The most important and ...
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Introduction One of the medical plants is lemon verbena with the scientific name of Lippia citriodora Kunth. It belongs to the family of Verbenaceae. The essential oil of lemon verbena has different compositions, which the most important of them are Geranial, Limonene, and Neral. The most important and commonly used physiological method after harvesting medicinal plants is the drying of plant organs which have high energy consumption. The temperature and the method of drying of these plants affect drug quality. The aim of this study was to investigate the effect of different drying methods on essential oil extraction efficiency and the drying time of lemon verbena leaves in a continuous flow dryer system and traditional drying method. Materials and Methods An amount of 150 g of lemon verbena leaves were dried in a continuous flow dryer equipped with the solar pre-heating system at three temperatures of 30, 40, and 50 °C, and three air velocities of 1, 1.5, and 2 m/s. To determine the significant difference between the effects of different air velocities and air temperatures in the dryer method, a factorial experiment was used in a completely randomized design with three replications for each treatment. The required heat for product drying was supplied by the combination of a gas water heater and a solar water heater. In the first stage, the gas water heater was off and the required thermal energy was provided only by the solar water heater. The radiation of solar energy heated the water in the solar water heater tank. After the water temperature reached the desired level, warm water was entered into the heat exchanger through an electric valve and a water pump. The air flow generated by the centrifugal blower was passed through the heat exchanger, and it was heated by the warm water. The warm air was then entered into the drying chamber through the air inlet pipe. If the temperature of the water in the solar water heater tank was lower than the desired level, the electric valve was actuated and made to direct the water flow to the inlet of the gas water heater before entering the water into the heat exchanger. At the same time, the gas water heater was turned on and provided the required thermal energy for warming up the water. In order to compare the quality of the dried product with the traditional drying method, 30 g of dried leaves from each treatment were submitted to hydrodistillation with a Clevenger-type apparatus and extracted with 450 ml of water for 3 h. A completely randomized design was used to determine the significant difference between the essential oil extraction efficiency of each method. Data were analyzed in SAS (Version 9.00) Software and the mean comparison was performed using Duncan's multiple range test. Results and Discussion The results showed that with increasing the air temperature and air velocity, the drying time of lemon verbena in the dryer significantly decreased. Also, with increasing airspeed to the dryer, moisture transfer from the product was performed faster. Finally, the drying time of the product was reduced. The highest essential oil extraction efficiency was obtained at 40 °C and 2 m/s (0.61%), while the lowest essential oil extraction efficiency was 0.23% in the sun drying method. The minimum drying time was obtained at 50 °C and the air velocity of 2 m/s in the dryer (110 min) and the maximum drying time was obtained in the (shade) traditional method (720 min). In this research, a new system was introduced in order to increase the uniformity and quality of the product in the process of drying the lemon verbena. In addition, by comparing the quality of dried product with traditional methods, it was found that the essential oil extraction efficiency in this dryer system was significantly (at 1% level) more than traditional drying methods. Also, the drying time in this system is much shorter than traditional drying methods. Conclusion In general, the results indicate that the drying methods in this study have a significant effect on the essential oil extraction efficiency and drying time of lemon verbena leaves. According to the results of this study, the use of this system for drying lemon verbena has advantages, such as increasing the quality of the product and reducing the drying time compared with the traditional methods. The most important advantages of using this system include: providing a considerable part of the required energy free, the use of warm water in a circulated circuit and the adaptation of the solar pre-heating system to the environmental objectives, the uniformity of product drying due to the continuous flow drying system, shorter drying time and the better quality of the product than traditional drying.
Volume 40 - Issue 1
R. Taghizadeh-Mehrjardi
Volume 40 - Issue 2
Behrooz pourmohamadali; M.H. Salehi; S.J. Hosseinifard; H. Shirani; I. Esfandiarpour Borujeni
Abstract
Introduction In recent decades, due to a significant increase of pistachio cultivation and uncontrolled exploitation of groundwater resources as well as reducing rainfall precipitation, groundwater level has dropped and the quantity and the quality of water has also been reduced. Therefore, agricultural ...
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Introduction In recent decades, due to a significant increase of pistachio cultivation and uncontrolled exploitation of groundwater resources as well as reducing rainfall precipitation, groundwater level has dropped and the quantity and the quality of water has also been reduced. Therefore, agricultural producers, researchers and policy makers need to pay more attention to appropriate land management as an important strategy to achieve greater yield per unit area and optimal use of soil and water resources. Crop yield prediction regarding its temporal and spatial variations has an important role in developing proper management programs. However, few studies have been carried out in relation to pistachio yield prediction using an acceptable range of features on regional scale. In the present study, pistachio yield modeling was performed by multivariate linear regression and artificial neural networkbased on soil, water and management features. Materials and Methods 129 orchard plots in different areas of Rafsanjan and Anar were identified and selected. The study area is located between 54° 56′ and 56° 41′ E, 29° 54′ and 31° 13′ N. Soil sampling, was performed from the areas under pistachio canopy and three soil depths of 0 to 40, 40 to 80 and 80 to 120 cm in each plot, fully expanded sub-terminal leaflets were randomly collected from non-fruiting branches, during the late July through August. Irrigation water of all orchards was also sampled. Moreover, for each orchard, a questionnaire was prepared to collect management and yield data. Soil quality indicators including particle size distribution, pH in saturated soil paste, electrical conductivity of saturated extract, soluble sodium, soluble calcium, soluble magnesium, available phosphorus and available potassium were determined for soil samples. The concentrations of phosphorus, potassium, iron, zinc, copper, manganese, calcium and magnesium in leaf samples and electrical conductivity in water samples, were also calculated. Finally, a dependent variable (pistachio yield) and 50 independent variables including soil, water and plant characteristics were used for modeling. For this purpose, stepwise multiple linear regression and artificial neural network technique were applied. Then, the study area was divided into 4 parts with the highest pistachio orchards densities and regression models were run for each part, separately. The ability of models to yield prediction was evaluated using the root mean square error (RMSE), relative root mean square error (% RMSE), adjusted coefficient of determination (adj - R2) and Durbin - Watson statistic (D – W). Results and Discussion The average of yield in the study area is about 1,700 kilograms per hectare. Results indicated that multiple linear regression could explain only 26 percent of the pistachio yield variation, but its accuracy increased when data became more homogeneous via dividing the study area into four parts. The model adjusted-R2 for Noogh, Anar, eastern suburbs and western suburbs orchards rose to about 92.4, 81.5, 95 and 53.6 percent, respectively. In all regression models except the model of western suburbs, at least one of the characteristics associated with irrigation water was significant. Artificial neural network with 9 neurons in a hidden layer, Tangent - sigmoid activation function and Levenberg - Marquardt training function, has a 98.3 percent accuracy in predicting pistachio yield in the study area (% RMSE = 13.8). Conclusion Multivariate linear regression model did not accurately predict the pistachio yield for the whole of study area whereas increasing data homogeneity and decreasing sources of variations, reduced complexity of relationships between features which resulted in increasing of the efficiency of linear regression to modeling these relationships. These models were highly sensitive to irrigation water features. Therefore, special attention should be paid to modern irrigation techniques and proper management approaches in order to enhance water efficiency. Overall, artificial neural network had greater accuracy compared to multivariate linear regression for pistachio yield modeling. This indicates the existence of non-linear and complex relationships between pistachio yield and the factors affecting yield and also the necessity of using modern and robust data mining tools for crop yield estimating. It seems that artificial intelligence techniques can be used as an efficient tool for developing proper management programs.
Volume 41 - Issue 2
Hossein Khademi; MohammadIsfahan Amirmohammadi
Abstract
Introduction: Potassium is a macroelement essential for plant growth and its importance in agriculture is well understood. Potassium in clay minerals is an important source of potassium for plants in many soils. No precise information is available on the impact of lime on potassium uptake by plants. ...
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Introduction: Potassium is a macroelement essential for plant growth and its importance in agriculture is well understood. Potassium in clay minerals is an important source of potassium for plants in many soils. No precise information is available on the impact of lime on potassium uptake by plants. Therefore, this study was conducted to investigate the effect of lime on K availability form phlogopite mineral in alfalfa rhizosphere.Materials and Methods: This study was conducted using a completely randomized design with factorial arrangement. Alfalfa was grown in media containing a mixture of quartz sand and phlogopite, different levels of lime (0, 2, 5, 12, 25%) and under two types of nutrient solutions (complete and potassium free) with three replications for a period of six months. Alfalfa shoots and roots were harvested and their potassium concentration was measured. The Data obtained from this experiment was statistically analyzed using SAS software and comparison of means was performed with the LSD test.Results and Discussion: The results showed that both shoot and root biomass was significantly affected by lime. Potassium concentration in shoot and root significantly reduced as the level of lime increased. The amount of soluble calcium increases as the level of lime in medium increases. This is mainly due to the hydrolysis of lime which also reduces the ratio of potassium to calcium and magnesium. This causes a great decline in potassium uptake by plant. Reduced uptake from the root surfaces of the plants in medium containing lime can also be caused by calcium oxalate precipitation on the root surfaces due to the abundance of calcium ions in the the root zone. Despite the fact that the amount of potassium supplied by different media has been the same, plants were not able to absorb equal quantity of potassium. Plants grown in lime-containing pots were indirectly deficient in potassium. Indirect exposure of plant to potassium deficiency means that, despite the high soil available K level, due to physiological reasons, potassium uptake by roots and its transfer to shoots is restricted. This is attributed to the negative effects of high concentration of magnesium and calcium compared to that of potassium in soil. Potassium concentration of plant roots was less than that of the shoots. This is mainly due to higher demand for K in shoots as compared to that in roots. Besides, the ability of plants to transfer potassium from root to shoot is very high. Shoot dry weight in plants with a complete nutrient solution major than the plants with a potassium free nutrient solution. Maximum dry weight was found in plants supplied with the complete nutrient solution with no lime added. In contrast, plants supplied with potassium free nutrient solution grown in pots containing 25% lime had the least dry weight. Lower root biomass could be caused by differences in physical characteristics of the root environment due to the presence of lime. Under potassium free nutrient solution, the amount of potassium uptake was significantly influenced by the amount of lime as such that the least potassium uptake of shoot and root occurred in treatments with %25 lime. The maximum K uptake (145.84 mg/pot) was obtained in plants treated with the complete nutrient solution. There was a highly significant correlation between the shoot dry weight and potassium uptake and also between the shoot dry weight and potassium concentration indicating that the plant shoot yield increases as the K concentration and uptake increase.Conclusion: The results obtained in this study clearly indicate that the presence of lime in the root zone could be a limiting factor for potassium uptake by plants. Although the concentration of potassium in plants was in the sufficient range defined by standards, but potassium uptake significantly reduced as the level of lime in medium increased. The decreasing trend was more obvious in the plants treated with potassium free nutrition solution. Plants treated with potassium free nutrient solution with no lime added to the medium have been able to take up a high amount of potassium. It appears that plant roots can influence on clay minerals to release potassium by the secretion of H+. But the presence of lime in the medium could release high level of Ca2+ ions into the solution, which, in turn, could reduce the release of potassium from phlogopite and its uptake by plants. In general, in media containing micaceous minerals as the only source of potassium, the presence of lime can have a negative impact on potassium release from minerals and its uptake by plants. Therefore, in calcareous soils with high potassium storage, the level of lime should be considered when potassium fertilizer is recommended. Besides, the amendment of highly calcareous soils by organic matters is suggested to improve the soil physical properties in order to have a better K uptake.
Volume 47 - Issue 1
Plant Nutrition, Soil Fertility and Fertilizers
samira mohamadi; Fardin Sadegh-Zadeh; Mohammad AIi bahmanyar; mostafa emadi; mahdi ghajar- sepanlu
Abstract
Introduction: Recovery of nutrients from plant residues is a sustainable and economical method in agriculture. Considering the important role of nutrients, it is essential to supply these elements in the soil and achieve the appropriate yield. The amount of nutrients in the plant residues after harvesting ...
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Introduction: Recovery of nutrients from plant residues is a sustainable and economical method in agriculture. Considering the important role of nutrients, it is essential to supply these elements in the soil and achieve the appropriate yield. The amount of nutrients in the plant residues after harvesting is very variable due to the difference between the species used. Each plant residue contains some nutrients that during the decomposition process, these nutrients can be available to the soil and crops in different amounts. In more detail, considering that the excessive use of chemical fertilizers has caused environmental problems and unused plant residues in the environment have created problems for the environment and farmers, therefore, to solve these problems, recovering important elements such as silicon from plant residues can be effective in improving the quality and quantity of many different products and plants. Rice straw, wheat straw and sugarcane bagasse are among the most common plant residues that have been studied in different studies to recover nutrients from them with different methods. In particular, rice straw is known as one of the most important plant residues that can be found in abundance in the north of Iran. Obviously, there is still a need for a better understanding of the amount of nutrients recovery from plant residues with different methods. And there is an effect of these elements on improving the condition of the soil. Considering that the excessive use of chemical fertilizers has caused environmental problems, as well as unused or underused plant residues in the environment have caused problems for the environment and farmers. The purpose of this study is to compare the residues of rice straw, wheat straw and sugarcane bagasse and the methods of recovering nutrients from these residues in order to add macro-nutrients (nitrogen, phosphorus and potassium) and micro-nutrients (iron, zinc, copper and manganese) into the soil.Materials and Methods: This research was carried out based on a factorial experiment in the form of a completely "randomized" design with three replications during 2022-2023. The treatments of plant residues in three levels (rice straw, wheat straw and sugarcane bagasse) and the methods of recovering elements from these residues in five levels (biochar, straw, digestion, ash and ash with acid) were examined. Soil samples, from a depth of 0-25 cm and with silty loam texture were randomly taken from the forest parts of Mazandaran province, Iran, characterized by a Mediterranean climate, Csa type, with an average annual rainfall of 676 mm, and average air temperature of 14 ℃, and then were air-dried. After preparing the samples, the characteristics of the treatments, macronutrients and micronutrients, including pH, electrical conductivity, total nitrogen, phosphorus, potassium, iron, zinc, manganese, copper, and silicon were measured. Analysis of variance (ANOVA) assessed the statistical significance of the differences in the studied variables among the different treatments. Tukey test was used for the post-hoc comparisons at a p-level < 0.01. Prior to the statistical analysis, QQ-plots were used to check the normality of sample distribution, and the data were square root-transformed whenever necessary. Moreover, the principal component analysis (PCA) was used to cluster the studied variables in groups related to the studied treatments.Results and Discussion: The results of analysis of variance showed the effect of plant residues and element recovery method on all studied characteristics including soil characteristics (pH, electrical conductivity and organic carbon), macronutrients (nitrogen, phosphorus and potassium) and micronutrients (silicon, manganese, copper, iron and zinc) were significant at the probability level of 1%. The results showed that the biochar treatment of rice straw had the maximum amount of pH (7.66), organic carbon (2.61%), nitrogen (0.24%), phosphorus (46 mg/g), potassium (781 mg/g) and silicon (261.33 mg/g) compared to other treatments. Also, the results of the compare means showed that sugarcane bagasse biochar treatment had the maximum amount of manganese (25.01 mg/kg), zinc (3.20 mg/kg), iron (48.27 mg/kg) and copper (2.20 mg/kg) compared to other treatments. The application of principal component analysis showed that three distinct groups (for rice straw/biochar, sugarcane bagasse/biochar and control treatments) were demonstrated, without clear overlap of the points related to these treatments and their element recovery methods.Conclusions: In general, this study confirmed that the treatment of rice straw residues and the method of recovering its elements through biochar play a significant role in increasing the quality and fertility of the soil and can be recommended to farmers.
Volume 44 - Issue 1
Precision Agriculture
Alireza Dahmardeh; Ali Shahriari; Mohammad reza Pahlavan Rad; Asma Shabani; MARYAM GHOEBANI
Abstract
Introduction Crop yield modeling is an important part of ecological modeling because it makes possible plant production prediction and increase understanding of how it works. In other words, plant and crop growth simulation and yield modeling are mathematical expressions of plant growth stages and processes ...
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Introduction Crop yield modeling is an important part of ecological modeling because it makes possible plant production prediction and increase understanding of how it works. In other words, plant and crop growth simulation and yield modeling are mathematical expressions of plant growth stages and processes under the influence of environmental and managerial factors. Wheat is one of the key crops grown worldwide and is a source of nourishment for millions of people around the world. Therefore, studying this strategic crop is very importance. On the other hand, more than 70% of wheat and 84% of barley in Sistan and Baluchestan province were produced in Sistan plain and wheat has the highest area under cultivation among different crops, in this arid region. So, the aim of this study was modeling wheat yield with some soil characteristics and determination of the most important soil factors affecting wheat yield in the Sistan plain.Materials and Methods This research was done in the educational and research farm of University of Zabol. Topsoil (0-30 cm) sampling of 100 soil sample was done randomly. Clay, silt, sand abundances and soil texture class, soil pH, electrical conductivity, apparent electrical conductivity of soil, organic carbon, phosphorus, potassium and nitrogen were measured by conventional methods. Wheat plant samples were taken from a one m2 plot and the grain weight, 1000-grain weight and total weight were measured. Performance modeling was performed by three methods of multi-linear regression (MLR), multi-layer perceptron (MLP) and support vector machines (SVMs) by two kernels types linear(SVM-L) and radial basic function (SVM-RBF). It should be noted, before modeling, 80% of the data were selected for modeling (or training) and 20% for testing (or validation) of the models. These data (training and validation) were the same for all models. Coefficient of determination (R2) and the root mean square error (RMSE) were the criteria for comparing the models. Sensitivity analysis was used to determine the most important soil factors affecting wheat yield.Results and Discussion The results of soil properties analyses showed that the soil of this area is non-saline and alkaline soil, has a medium to coarse soil texture and the soil fertility conditions are poor to moderate. The results of comparing the models showed that the highest R2 and the lowest RMSE in estimating all three wheat yield indices were related to the MLP method (grain weight with R2= 0.61, 1000-grain weight with R2= 0.64 and total yield with R2= 0.76). After MLP, with less difference, the SVMs method with two kernels types of linear (grain weight with R2= 0.54, 1000-grain weight with R2= 0.44 and total yield with R2= 0.65) and radial basic function (grain weight with R2= 0.48, 1000-grain weight with R2= 0.58 and total yield with R2= 0.67) showed the better modeling and finally the MLR (grain weight with R2= 0.20, 1000-grain weight with R2= 0.27 and total yield with R2= 0.40) showed the lowest accuracy in modeling the yield components of wheat. The results of sensitivity analysis of wheat yield components showed that total soil nitrogen, clay, silt and soil organic matter had the highest on wheat yield components (grain weight: nitrogen, clay and organic matter; 1000-grain weight: nitrogen, silt and clay; and total yield: clay, organic matter and nitrogen) and soil pH had the least effect on it, maybe because of its low variation.Conclusion Due to harsh environmental conditions in the arid regions, the study of crops yield is very important for the optimal management of facilities and resources. Investigating the application of several wheat yield modeling methods using some soil characteristics in the arid region of Sistan showed that the perceptron neural network (MLP) performed better in predicting the yield components of wheat than other models. Also, some chemical and physical properties of soil that affect the soil fertility and water storage conditions in the soil (soil nitrogen, organic matter, clay and silt contents), were the most affecting factors on the yield of wheat in this arid region. It is important to note that attention to other soil properties as well as climatic parameters and studies and monitoring wheat yield for several years can can lead to more accurate modeling of this strategic crop and thus optimal farm management.
Volume 46 - Issue 1
Soil Chemistry and Pollution
Khosro Betyar; Neda Moradi; Abdolamir Moezzi; Shila Khajavi-Shojaei
Abstract
Introduction Phosphorus deficiency is one of the major problems of calcareous soils and a limiting factor for crop production in these soils and excessive use of phosphate fertilizers can cause pollution in soil and water. The use of organic amendments such as compost, biochar or a combination of them ...
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Introduction Phosphorus deficiency is one of the major problems of calcareous soils and a limiting factor for crop production in these soils and excessive use of phosphate fertilizers can cause pollution in soil and water. The use of organic amendments such as compost, biochar or a combination of them can be effective in improving the amount of available phosphorus of the soil. For this purpose, the effect of combined application of compost and biochar of sugarcane bagasse on phosphorus sorption and desorption were investigated.Materials and Methods Sugarcane bagasse and compost were provided from Debal Khozaei agro-industry Company. The oven-dried sugarcane bagasse 105 ºC were pass through 2 mm sieve and slow pyrolysed at 500 ºC using a laboratory muffle furnace with a heating rate of 5 ºC min-1 and presence of N2 flow to provide an anoxic condition. Some physico-chemical properties of samples were determined. The soil sample was collected from 0-30 cm of the campus of Shahid Chamran University of Ahvaz, Ahvaz, Khuzestan province, SW Iran (48° 65′91.12′′E31°30′53.82′′N). The studied soil classified as a Typic Haplocalcids. The air-dried soil samples were sieved (˂ 2 mm) and used for physico-chemical analysis. The incubation experiment was conducted with 7 treatments. The treatments including (1) control (without any amendments), (2) 100% sugarcane bagasse, (3) 100% sugarcane bagasse compost, (4) 100% sugarcane bagasse biochar, (5) 50% compost +50% biochar, (6) 75% compost + 25% biochar, (7) 25% compost + 75% biochar were added as 2% w/w to soil. The 200 g air-dried soil and treatments were mixed and kept in poly-ethylene containers for 120 days. Samples were incubated in 25 2 ºC and soil moisture was adjusted to soil field capacity using distilled water during the incubation time. At the end of incubation time, soil phosphorus sorption isotherm was measured. A 2.5 g of each treatment was transferred to a 50 ml centrifuge tube. Then, a 25 mL of CaCl2 0.01 M containing 0, 10, 20, 40, 60, 80, and 100 mg P L-1 (prepared from KH2PO4) was added to each centrifuge tube. Two drops of chloroform were added to each centrifuge tube to inhibit microbial growth. Samples were equilibrated at 25 1 ºC for 24 h on shaker at 150 rpm, and then centrifuged for 5 min at 3000 rpm and pass through 0.45-μm filter paper. The phosphate desorption was conducted on soil remaining in the filter immediately after sorption experiment. For this purpose, each treatment was resuspended with 25 ml of CaCl2 0.01 M solution without phosphate and shaken for 24 h. after collecting the supernatant, desorbed phosphate was measured. For assessing the adsorbed phosphate, the difference between the initial phosphate concentration and the phosphate concentration at equilibrium was calculated. The Langmuir, Freundlich and temkin isotherm models were used to describe the sorption of phosphate. In addition, some phosphorus buffering indices including maximum buffering capacity (MBC), standard buffering capacity (SBC), equilibrium buffering capacity (EBC) and standard phosphorus requirement (SPR) were obtained from P sorption equations at 0.2 mg P L-1 concentration in soil solution. The experimental data were fitted by Microsoft Excel-SOLVER and graphs were plotted by Microsoft Excel.Results and Discussion The soil was had loam texture, with low SOC content and high pH and calcium carbonate content, also the results of the characteristics of sugarcane bagasse compost and biochar showed that the compost had high salinity and the biochar had high pH and C/N ratio. The amount of phosphorus absorption increased with increasing the initial concentration of phosphorus in the treated soils. The highest and lowest amount of phosphorus absorption were in the control in compost treatments, respectively. In general, different levels of biochar and compost treatments caused a decrease in phosphorus absorption compared to the control treatment. The results showed that P sorption and desorption are described well by the Freundlich and Langmuir equations with a high correlation coefficient; however, the Temkin equation described the P sorption and desorption in the soils poorly. Biochar and compost treatments significantly decreased the Freundlich n parameter. Results showed that the effects of compost and 75% compost + 25% biochar were significantly greater than the effects of other treatments on the n parameter exponential adsorption equation. Application of different treatments of sugarcane bagasse compost and biochar application caused a significant increase in MBC (25.4-70.7%) and EBC (33.1-69.4%). The standard P requirements (SPR) were lower in soils treated than in control soil.Conclusion The results showed that the combined application of biochar-compost of sugarcane bagasse reduced the sorption and increased desorption of phosphorus. The maximum buffering capacity (MBC) and equilibrium buffering capacity (EBC), standard buffering capacity (SBC) and standard phosphorus requirement (SPR) in compost and compost 75% + biochar 25% showed more decrease than the control. In general, the results of this study indicate that the combined application of biochar-compost of sugarcane bagasse reduces phosphorus sorption in soil in calcareous soils, which can increase the availability phosphorus for plants.
Volume 45 - Issue 2
Ali Monsefi; Mojtaba Norouzi Masir; Yazdan Izadi
Abstract
Introduction: Despite the many benefits of tillage to crop establishment and production in the past, new herbicide and minimum-tillage management systems have drastically changed today's methods of crop production. Although tillage systems are used to increase soil porosity, they are a short-term solution ...
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Introduction: Despite the many benefits of tillage to crop establishment and production in the past, new herbicide and minimum-tillage management systems have drastically changed today's methods of crop production. Although tillage systems are used to increase soil porosity, they are a short-term solution that has negative consequences on surface soil structural stability, surface crop residue, and surface soil organic carbon, which are critical features that control water infiltration and subsequent water transmission and storage in soil. Physical and chemical properties of soil such as organic matter of soil is a key attribute of quality that affects water infiltration and soil aggregation. The use of conservation tillage along with the application of appropriate management methods such as conservation of residues, the use of proper rotation and weed control caused to stabilize the particles of soil, prevent the destruction of soil structure and increase soil organic matter. Therefore, changing the method of tillage systems from conventional to conservation, especially in crop rotation cycles, is inevitable. Our objectives were to summarize these findings and present additional information with particular emphasis on changes physical and chemical characteristics in different soil depths due to adoption of conservation tillage in corn-wheat crop rotation.Materials and Methods: The present study was performed to investigate tillage systems (4 levels including ZT-ZT: Zero Tillage-Zero Tillage; ZT-CT: : Zero tillage-Conventional Tillage; CT-CT: Conventional Tillage-Conventional Tillage and CT-ZT: Conventional Tillage-Zero Tillage) and 4 levels of weed management (including W1: Control; W2: Post-emergence Nicosulfuron herbicide + hand weeded in cultivation of corn and post-emergence Metribuzin herbicide + hand weeded in cultivation of wheat; W3: Pre-emergence Atrazine + post-emergence Nicosulfuron herbicides in cultivation of corn and post-emergence Clodinafop + post-emergence Bromoxynil+MCPA herbicides in cultivation of wheat; W4: Wheat residues as a mulch + post-emergence Nicosulfuron herbicide in cultivation of corn and corn residues as a mulch + Metribuzin herbicide) on some physical and chemical properties of soil depths (D1: 0 -15 and D2: 15-30 cm) in corn-wheat rotation during the 2021-22 croping year in the farms of Shavur Agricultural Service Center of Shush city was implemented as a split-factorial in the form of a randomized complete block design with three replications and 96 samples. Results and Discussion: The results showed that interaction of the studied treatments significant effects of the all studied traits except for soil pH. The minimum of soil bulk density was observed in conventional tillage-zero tillage × Wheat residues as a mulch + post-emergence Nicosulfuron herbicide in cultivation of corn and corn residues as a mulch + Metribuzin herbicide as weed management treatment × 0-10 cm soil depths treatment with an average of 1.390 g/cm3, also, the highest hydraulic conductivity of the soil was obtained in conventional tillage-conventional tillage × pre-emergence Atrazine + post-emergence Nicosulfuron herbicides in cultivation of corn and post-emergence Clodinafop + post-emergence Bromoxynil+MCPA herbicides in cultivation of wheat × 0-15 cm soil depths treatment (with an average of 0.994 cm/h). The highest amount of organic matter (with an average 0.771 percent) and phosphorus and potassium elements was achieved in zero tillage-zero tillage × wheat residues as a mulch + post-emergence Nicosulfuron herbicide in cultivation of corn and corn residues as a mulch + Metribuzin herbicide × 0-15 cm soil depths treatment (with averages of 13.96 and 234.7 mg/kg, respectively). Interaction effects results (tillage system × sampling depth) indicated that highest amount of total nitrogen was achieved in the zero tillage-zero tillage (ZT-ZT) on soil surface layer (0-15 cm sampling depth) with an average 122.0 kg / ha with an increase of 40.1% compared to the other treatment such as zero tillage-conventional tillage (ZT-CT), conventional tillage-conventional tillage (CT-CT) and conventional tillage-zero tillage (CT-ZT) and soil substrate (15-30 cm sampling depth, with an average of 0.87 kg/ha). In addition, the preservation of residues in the form of mulch and the use of post-emergence Nicosulfuron and Metribuzin herbicides led to maintaining the balance of soil pH in the corn-wheat rotation.Conclusion: Steady-state soil chemical and physical properties was greater under zero tillage than under conventional tillage as a result of soil structural improvements associated with surface residue accumulation and lack of soil disturbance. In addition, our data indicate that conservation tillage along with the application of crops residues in corn-wheat crop rotation is a viable management strategy to improve soil quality in the warm, semiarid region of Khuzestan Province. This strategy could lead to high production, minimal negative environmental impacts, and a socially acceptable farming system. Therefore, the use of previous crop residues in tillage systems will have a positive effect on improving the physical and chemical properties of the soil.
Volume 46 - Issue 2
Plant Nutrition, Soil Fertility and Fertilizers
Mina Taghizadeh; Zeinab Azimi Senejani; Mousa Solgi
Abstract
Introduction One of the important proceedings in propagation process of plants is improving the speed of rooting and shortening this propagation period. Today, use of natural materials as an alternative for chemical fertilizer is concerned with successful rooting of cuttings in ornamental plants that ...
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Introduction One of the important proceedings in propagation process of plants is improving the speed of rooting and shortening this propagation period. Today, use of natural materials as an alternative for chemical fertilizer is concerned with successful rooting of cuttings in ornamental plants that in some cases have perceived well and effective influence of these biofertilizer compared with chemicals. Zamioculcas zamiifolia is a valuable ornamental indoor plant. The production of this plant in short time is commercially important. An important stage in the process of accelerating this plant production is to improve the rooting and shortening its growth stage. Therefore, the simultaneous effect of mycorrhizal biofertilizer and biochar on Zamioculcas zamiifolia propagation was studied in this research.Materials and Methods This study was performed in the greenhouse in the faculty of agriculture and environmental science of Arak University with controlled conditions of 25 ◦C temperature, 70% humidity and 10,000 lux of light. Treatments were included biochar 5% + arbuscular mycorrhizal biofertilizer 6%, biochar 10% + arbuscular mycorrhizal biofertilizer 6%, biochar 5% + arbuscular mycorrhizal biofertilizer 12%, and biochar 10% + arbuscular mycorrhizal biofertilizer 12%, and control (without biochar and arbuscular mycorrhizal biofertilizer). The arbuscular mycorrhizal biofertilizer was mixture of Clarodeoglomus etunicatum, Rhizophagus irregularis, Funneliformis mosseae. The experiment was performed as a completely randomized design (CRD) at three replicates. The pots were containing cocopeat + perlite (1:1) and different treatments of arbuscular mycorrhiza biofertilizer and biochar. Morphological and physiological traits such as off-shoot number, Leafy cuttings color, Leaf width, Leaf length, Shoot length, root number, root length, rhizome diameter, chlorophyll a, b and total chlorophyll content, fresh weight (FW) of roots and shoots, the dry weight (DW) of roots and shoots, Saturation weight, relative water content (RWC), biomass, electrolyte leakage and arbuscular mycorrhizal root colonization were measured after 9 months. Results and Discussion Biochar and arbuscular mycorrhiza biofertilizer application in propagation medium increased off-shoot growth of Zamioculcas zamiifolia. The results showed that the highest roots number was obtained in the treatments of arbuscular mycorrhiza biofertilizer 12% + biochar 10% which was followed by arbuscular mycorrhiza biofertilizer 6% + biochar 5%. The maximum root length was observed by arbuscular mycorrhiza biofertilizer 12% + biochar 5% treatment. The root colonization had a positive correlation with the number of off-shoot, leaf size, shoot FW and leaf chlorophyll content. The application of biochar 10% + arbuscular mycorrhiza biofertilizer 6% treatment caused an increase in the height of the shoot about 3.3 times more than the control. The highest rhizome diameter was observed in biochar 10% + arbuscular mycorrhiza biofertilizer 6% treatment. The maximum off-shoot number was measured in the treatment of biochar 10% + arbuscular mycorrhizal biofertilizer 6% treatment which was 1.8 times more than control. No signs of colonization were observed in the control, but the roots colonization in the arbuscular mycorrhiza biofertilization treatment 12% was 1.6 times more that in the arbuscular mycorrhiza biofertilizer 6%. Increasing the amount of biochar and arbuscular mycorrhiza application in the propagation medium enhanced arbuscular mycorrhiza roots colonization of Zamioculcas zamiifolia. A significant positive correlation was observed between the number of off-shoot and the total biomass (r=0.95). A high positive correlation was observed between the fresh weight of shoot and the saturated weight (r=0.95). There was a significant positive correlation between saturated weight with total chlorophyll (r=0.97) and total biomass (r=0.96). The relationship between total chlorophyll and biomass was a significant positive (r=0.95). There was a significant positive correlation between the root colonization and chlorophyll a (r=0.83). A significant negative correlation was detected between dry weight of shoot and dry weight of root (r=0.94) and dry weight of root with relative water content (r=0.95). Conclusion Generally, in the most of studied traits, the use of biochar and arbuscular mycorrhiza biofertilizer in the culture medium improved the off-shoot growth and rooting characteristics of Zamioculcas zamiifolia compared to the control. Shortening the propagation period of this slow growth and luxury plant is significant aspects in the production of this ornamental plant that reduce production costs and make the product more cost-effective. The use of biochar 10% + arbuscular mycorrhiza biofertilizer 6% in culture medium is recommended to improve the quantitative and qualitative properties through the propagation of this ornamental houseplant.
Volume 44 - Issue 2
najmeh salari ardsiri; Majid Hejazi-Mehrizi; hormazd naghavi; rabi Behrooz; Majid Fekri
Abstract
Introduction providing the food needed by the world's ever growing population has led to changes in cultivated areas, water resources, and the overuse of chemical fertilizers and consequent environmental pollution. Providing essential nutrients to the plant is one of the most important factors related ...
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Introduction providing the food needed by the world's ever growing population has led to changes in cultivated areas, water resources, and the overuse of chemical fertilizers and consequent environmental pollution. Providing essential nutrients to the plant is one of the most important factors related to the optimum production of agricultural crops. In recent years, most of essential nutrients are provided through the natural fertility of the soil and chemical fertilizers. Today, one of the most important ways to increase soil fertility is the use of fertilizers. Consistent and excessive use of fertilizers such as nitrogen and phosphorus (in the form of ammonium salts, urea, nitrate or phosphate compounds) in recent years has caused problems in the agriculture and environment. In recent years, the efficiency of application of nitrogen, phosphate and potash fertilizers has been about 30-35, 18-20 and 35-40-40, respectively. This indicates that a large part of the fertilizer used remains in the soil or enters the aquatic ecosystems and negatively affects the natural balance and biodiversity of agricultural lands. Accordingly, to overcome these problems, it is necessary to use solutions such as better water and fertilizer management, change in the structure of fertilizers and the use of new technologies. One of the effective methods to overcome the problems of low efficiency of chemical fertilizers is to develop the controlled release fertilizers. Slow-release fertilizers can be a good way to overcome the problems expressed by common chemical fertilizers. Release control fertilizers are usually prepared using the coating method and reducing the solubility of water-soluble fertilizers by creating a physical barrier. The biggest problem with slow release fertilizers is their high production cost. Therefore, it is necessary that the fertilizers covering chemical fertilizers be economical and compatible with the environment and have desirable coating properties. Nanocomposites are among the polymer coatings that have received much attention in recent research. Among the many materials used to form nanocomposites, polysaccharides such as cellulose, starch for economic reasons, biocompatibility, non-toxic and biodegradable are widely used compared to synthetic polymers. Despite many studies in the field of fertilizer production, the use of slow release fertilizers as a source of required nutrients and also the use of hydrophilic and hydrophobic polymers such as pure cellulose compounds with conventional fertilizers have not been studied. The need for this research is to use cellulose from agricultural waste in slow release of chemical fertilizers in order to increase the efficiency of fertilizers, prevent its overuse in agriculture, and also waste agricultural waste around orchards. In this study, cellulose compounds were extracted from paper, palm and pistachio branch and these cellulose compounds were then used to slow the release of urea fertilizers.Materials and Methods First, the sufficient amounts of pruned wastes from branch of palm, pistachio, and paper waste, were collected from agricultural regions in Kerman Province; then they were transferred to the laboratory of Kerman Agricultural Research Center. After washing and drying, the samples were ground. In the next step, 10 g of each of the air-dried cellulosic sources was passed through a 60-mesh sieve in an Erlenmeyer flask with 200 ml of 1% NaOH solution for 1 h. Then, it was entirely washed with distilled water and the resulting contents in the Erlenmeyer flask were re-boiled along with a mixture containing 300 ml of 80% acetic acid plus 30 ml of 67% nitric acid for 30 min at 120°C. At the end of the reaction time and partial cooling of the mixture, the cold distilled water was added to the reaction mixture and the resulting cellulose pastes were then washed thoroughly with distilled water until reaching the neutral pH. At the end, the samples were air-dried. Finally, the cellulose samples were washed with distilled water and air dried. In the second stage, slow release of urea fertilizer with cellulose from palm wastes in a ratio of 1 to 2 (fertilizer to cellulose) was made and they were made in the form of small tablets. Nitrogen release kinetics from these fertilizers in soil up to 90 days were measured and kinetic equations were also investigated.Results and Discussion After cellulose extraction of wastes, FTIR device was used to identify the extracted celluloses and compare them with Sigma Aldrich pure cellulose. The peaks obtained from the FTIR apparatus were similar to the pure cellulose peaks. The yield of extracted cellulose in the form of paper waste was 70%> palm branch 33%> branch of pistachio 28%. In the second stage, the extracted cellulose was used to cover urea fertilizer in a ratio of 1 to 2 (urea fertilizer to cellulose) and the desired fertilizer was made in the form of small tablets with diameter of 0.5 cm and height of 2 cm. The SEM scanning electron microscope was used to study the structure of the manure. Microscopic images showed that the urea fertilizer placed as white spherical particles around the cellulose rod particles, indicating that the urea fertilizer particles adhered to the cellulose particles without any adhesive. The FTIR diagram of the fertilizer showed that the shift of the diagram upwards at the common wavelengths in urea and pure cellulose and a strong physical bond is established between them. Nitrogen release kinetics for all treatments that were less than pure urea fertilizer and significant differences observed between treatments and pistachio branch cellulose caused a slower release of urea fertilizer. The kinetic equation of the power function was selected as the best model for fitting the kinetic data. The studied wastes in this study have a high potential for producing pure cellulose to slow the release of urea fertilizer.
Volume 43 - Issue 2
Hadi Karimi; Hossein Navid; Bahram Besharati
Abstract
Introduction Seed drills are the planters that plant the seeds in rows in close proximity. The sowing rates of seed drills are regulated by fluted roller seed metering mechanism which may have different seed numbers each time in their grooves. Given the nature of these types of seed, it is not possible ...
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Introduction Seed drills are the planters that plant the seeds in rows in close proximity. The sowing rates of seed drills are regulated by fluted roller seed metering mechanism which may have different seed numbers each time in their grooves. Given the nature of these types of seed, it is not possible to completely prevent the change in seed flow rate. In addition, during sowing with seed drills over a field, seedless areas may remain largely due to unavoidable problems, such as a malfunction of the seed metering mechanism, clogging of seed tubes, emptying of the seed hopper, etc. Due to the closed-loop of the sowing process seed drills, seeds can be placed with an undesirable population per unit area. In this regard, the seed drill performance monitoring system by providing online feedback on the operating status of various parts could optimally improve sowing efficiency. Materials and Methods At first step, to develop a seed drill monitoring system, an infrared seed sensor was designed to be installed in sowing tubes of seed drills. To establish an equation for mass flow rate estimation, the sensor was evaluated by a roller seed metering system and three types of seeds including chickpea, wheat and alfalfa (respectively, representative of large, medium and fine seeds). It was found that a completely acceptable equation can be made between the voltage and the flow rate of each type of seed. Afterwards, designing and constructing a seed drill performance monitoring system based on developed seed flow sensors was considered. In the proposed monitoring system, the seed flow sensors were installed separately in each seed tube, so that the amount of seed flow rate, the presence or absence of seed flow in the graphical interface can be displayed. The forward speed is measured with the Hall sensor and, taking into account the mass flow rate of the seed, the sowing rate is calculated according to the seed mass sown per unit area. During operation, the system registers sowing data with the location information provided by the GPS module. The overall information from the sowing performance is then recorded simultaneously on the embedded memory card and displayed in the graphical interface. In addition to sowing operations, the proposed system continuously indicate the seed and fertilizer levels of the hoppers measured by ultrasonic sensors. Results and DiscussionThe developed monitoring system was constructed and installed on a seed drill, equipped with 13 sowing units. With applications of three levels of ground speed and sowing speed during field experiment, the sensing system is assessed under outdoor operating conditions, including planter vibrations, tractor speed variation, and the dust. The field test resulted in a correlation coefficient of 85 percent between the mean of the weighted data obtained from the scale and the mass flow estimates. The outdoor experiments results appeared to be weaker than laboratory evaluation. Regarding the outdoor operating conditions, the obstruction of the optical elements by the dust seems to have the most adverse effect on the performance of the proposed sensing system. In addition, increased forward ground speed and sowing rate resulted a negative impact on the performance of the developed seed flow sensor. So that with increasing speed and mass flow rate, the passing seed flow becomes denser and more seed remains hidden from the measuring elements. In the case of the hopper level control sensor, ultrasonic sensors had proven to be a suitable and inexpensive practical solution for checking the fertilizer and grain level. Conclusion There are some suggestions for the development of the sowing monitoring system in future research. When designing an optically based seed sensor, optical elements with a smaller propagation angle are preferred. In this case, the error caused by optical overlap would be minimized. The sowing performance monitoring can be triggered as appropriate feedback received from the forward speed sensor. The flow sensor can therefore only be activated when the tractor is moving and exceeds a predefined threshold. In this case, the environmental effects that affect the performance of the seed sensor can be automatically zeroed when the tractor is stopped. Reduce the wiring between system components by establishing wireless communication protocols, CAN, etc., the use of new operating methods for the modification and cleaning of infrared elements against dust, the development of a graphical interface in Android and iOS systems and the use of tablets and mobiles Phones to display sowing information are some of the issues that could be considered in future system updates and developments.
Volume 44 - Issue 3
Ahmad Daneshkhah; Mahmoud Ghasemi Nejad raeini; Mohammad Amin Asoodar; Afshin Marzban; Mokhtar Heidari
Abstract
AbstractIntroduction In recent decades, population growth has led to changes in dietary behavior and a significant increase in global demand for food production, which has led to the promotion of heavy use of agricultural land. water shortage in arid and semi-arid regions is one of the most important ...
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AbstractIntroduction In recent decades, population growth has led to changes in dietary behavior and a significant increase in global demand for food production, which has led to the promotion of heavy use of agricultural land. water shortage in arid and semi-arid regions is one of the most important factor that affect crops production. The use of different conservation tillage methods such as minimum tillage and the use of organic and inorganic mulch as methods used in sustainable agriculture, can reduce water and energy consumption in an agricultural system. Soil water affects plant growth and development. So that even a small change in soil water content can significantly change the productivity of crops. Soil cover or mulch is one of the management strategies to increase water use efficiency of agricultural products.Materials and Methods In this study, research was conducted to investigate the effect of conservation tillage methods and plasticulture patterns on water use efficiency and strawberry crop yield in 1398. The water use efficiency was calculated to assess the effects of tillage and plastic covers in the field. . The experiment was conducted using of factorial design in the form of randomized complete blocks with three replications. The plots included two types of tillage systems (conventional and conservation) and three methods of plastic cover (planting under plastic, over plastic and without plastic coverage). This experiment was performed in 18 plots with dimensions of 0.8×15 meters. 3 rows were planted in each plot. The distance between sub-plots was 75 cm as a ridge, the distance between main plots was 1 and a half meters and the distance between replicates was 2 meters. Water use efficiency (WUE) is one of the most important indicators for measuring agricultural water productivity. This index is actually the ratio of the amount of product produced per amount of water consumed (evaporation-transpiration) of the plant. In this definition, instead of evaporating and transpiration of the plant, the amount of water used in the field can be replaced and the amount of crop production per unit volume of water used in irrigation can be obtained. The higher this ratio, the better the water consumption.Results and Discussion The two factors of tillage and planting pattern only affected soil moisture content at a depth of 0-10 cm and no significant effect was observed between different treatments at a depth of 10-20 cm. Minimum tillage in the pre-irrigation and post-irrigation stages has the highest moisture content. Conventional tillage disturbs the soil more than minimum tillage, increasing pores and unevenness of the soil surface, thereby increasing surface evaporation. Planting pattern had the highest moisture content and over plastic planting pattern had the lowest moisture content. Plastic cover is a barrier that prevents soil water from evaporating and keeps the root zone moisture regime at more stable levels, thus reducing the need for irrigation and preventing physiological disorders related to nutrients and water. There is no significant difference between tillage factor in two levels of conventional and low tillage and only planting pattern at 1% level has a significant difference. Different planting patterns significantly affected strawberry yield. According to the comparison of the average, the highest yield was related to the planting pattern on plastic and the lowest was obtained on the planting pattern without plastic. Since the yield of strawberries in different tillage methods was not significantly different and in this study the same amount of water was used in different methods. Therefore, tillage methods had no significant effect on strawberry water productivity.Conclusion The data was shown that the use of conservation tillage and plasticulture increased soil moisture retention by 22% which is due to the prevention of evaporation of soil moisture by Plastic mulch and Plant residue cover and less soil disturbance in conservation tillage. Conservation tillage has no significant effect on strawberry yield due to the slow trend in changing soil properties, but plastic mulch increased strawberry yield by 31.71% due to the increase in soil moisture retention. Since the type of tillage did not have a significant effect on strawberry yield in this study, therefore, tillage does not have a significant effect on water use efficiency, but different planting patterns, due to affecting yield, significantly increase water use efficiency here.
Volume 43 - Issue 3
Safoora Nahidan; Masoumeh Faryadras; Vajiheh Dorostkar
Abstract
Introduction Traditional organic manure can be potentially beneficial for soil physical, chemical and biological properties by improving organic matter of soils. Recently, biochar, a carbon rich product of biomass produced by thermochemical conversion under oxygen-limited conditions, has been studied ...
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Introduction Traditional organic manure can be potentially beneficial for soil physical, chemical and biological properties by improving organic matter of soils. Recently, biochar, a carbon rich product of biomass produced by thermochemical conversion under oxygen-limited conditions, has been studied for its effects as a soil amendment. The use of a modified form of manure as manure biochar for soil improvement reduces some environmental, food safety and disposal problems of manures. However, biochar application has been shown to have a positive and negative effect on soil fauna such as earthworm depending on the type of feedstock for its production. Since earthworm function affects physical properties and amount of organic carbon of soils and because of the different effect of biochar and its feedstock on earthworm activity, this study hypothesizes that earthworm may differently alter soil physical properties and aggregates associated carbon in the biochar and its feedstock amended soils. The purpose of this study was to investigate the effect of cow manure and its biochar in the presence and absence of earthworm on bulk density, total porosity, saturated hydraulic conductivity, aggregate stability and content of organic carbon in soil aggregates during 30 and 90 days incubation.Materials and Methods A completely randomized design with 2×4×2 factorial treatment combination was used in triplicates. Treatment variants examined in this study included the following: (i) 2 levels of amendment type (cow manure and its biochar), (ii) 4 levels of applied amendment rate (0, 1, 2 and 5%), (iii) 2 levels of earthworm (with and without earthworm). The biochar was produced from cow manure (passed through 2 mm mesh) by slow pyrolysis at 450 °C. For this experiment, the soil sample was passed through 4 mm mesh. Then, amended soil and the control were moistened up to 70% water holding capacity. Then 5 adult Eisenia fetida with fully-developed clitellum and similar weight were added to half of them. Treatments were then incubated at laboratory temperature and constant moisture for 30 and 90 days. Based on evaporation loss, the soil moisture was kept constant by regular weighing of each pot. At the end of each time (30 and 90 days), samples were taken from different treatments to determine bulk density, total porosity, saturated hydraulic conductivity. Also, soil aggregates were separated by wet sieving, then aggregate size distribution was determined and mean weight diameter (MWD) was calculated, also organic carbon content in each aggregate size fraction was determined. Results and Discussion The results showed that the application of both organic amendments was effective in decreasing soil bulk density, increasing total porosity, saturated hydraulic conductivity and aggregate stability, but the effects of organic amendments on these physical properties were more pronounced in cow manure- than biochar-amended soils. Further reduction in bulk density following manure application is attributed to a dilution effect, resulting from mixing of the lighter material of manure with denser mineral fractions of the soil. In addition, cow manure has more content of organic carbon than its biochar which can increase total porosity by promoting aggregation. The greater porosity and aggregation of soils as affected by the application of organic amendments are apparently responsible for the increased saturated hydraulic conductivity. The results showed that the effect of cow manure on the soil physical properties reduced with time more rapidly than its biochar. It might be attributed to lower stability of manure to degradation than biochar in soils because manure contains higher content of labile organic compounds compared to biochar. Our results also showed that application of organic amendments led to increase organic carbon in soil aggregates, especially in 4-2 mm aggregates, indicating that the large macro-aggregates can be considered as a susceptible indicator to organic carbon managements in soil. Also, the organic carbon content of 4-2, 2-0.25 and 0.25-0.05 mm aggregates was 42.8, 27.8 and 20.8% (in 30 days incubation) and 27.2, 28.6% and 20.6% (in 90 days of incubation) higher in cow manure- than biochar-amended soils. The results also showed that earthworm reduced soil bulk density, increased total porosity, saturated hydraulic conductivity and aggregate stability regardless of soil amendment but such effect on bulk density and total porosity was more pronounced in cow manure- than biochar-amended soils. It means that type of organic amendments can influence on earthworm activity, thereby altering some soil physical properties. Also, earthworm led to increase carbon content in soil aggregates, especially in smaller aggregates.Conclusion The results showed that although application of cow manure improved soil physical properties more than cow manure biochar at both incubation times, it seems that cow manure biochar has a more stable effect on the soil physical properties over time. Also, application of organic amendments can lead to increase soil organic carbon by further increasing C in larger aggregates. Other results indicated that the improving effect of earthworm on soil physical properties (except for bulk density and total porosity) did not depend on the type of applied organic amendment in soil. The effect of earthworm on bulk density and total porosity was more pronounced in soils amended with cow manure than its biochar. Also, it is thought that earthworm increases organic carbon in soil by physical stabilization of organic carbon in soil aggregates, especially in smaller aggregates.
Volume 45 - Issue 4
Soil Chemistry and Pollution
Mina Hashemi Tazangi; Soheila Ebrahimi; Reza Ghorbani Nasrabadi; Seyed Alireza Movaheddi Naeeni
Abstract
Background and objectives: Hydrocarbons derived from petroleum and gas have gained increased attention as the most important fossil resources of energy as well as crude material for petrochemical industries. However, environmental issues such as pollution due to extraction, exploitation and transportation ...
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Background and objectives: Hydrocarbons derived from petroleum and gas have gained increased attention as the most important fossil resources of energy as well as crude material for petrochemical industries. However, environmental issues such as pollution due to extraction, exploitation and transportation of these materials has raised concerns as an environmental warning. In recent years, utilization of biochar (via biomass burning) has been regarded as a soil refiner to reduce or eliminate pollution, especially in in situ studies. Biochar is a product rich in carbon, which is produced during the pyrolysis of various types of woods, fertilizers, leaves, straws as well as agricultural wastes under abiotic conditions. It seems that biochar can be suggested as a suitable compound to manage biomass wastes as well as to enhance soil fertility. Thus, kinetic behavior of biochar in reduction of gasoil pollution of soil, its changes of this pollutant over time and changes in the microbial activity in this time period were investigated.Materials and methods: The soil polluted with gasoil was collected from the vicinity of the gasoil tanker located in Shiraz refinery. The soil had been polluted for years due to the leakage of gasoil. Then, after the measurement of the initial total petroleum hydrocarbon content and physical and chemical properties (soil texture via hydrometry, electrical conductivity in the saturated paste, available phosphorous using the Olsen method, total nitrogen using the Kjehdahl method, pH of soil in the saturated paste, soil carbon using the Walkey and Black method) of the polluted soil, 700 gram soil samples containing wheat straw biochar at one and two mm sizes and 20, 40, 60, 80 and 100 g kg-1 weight doses were prepared as split-split-plot experiment based on a completely randomized design with three replicates. The samples were then rested in a 50% constant humidity for four weeks at 28 ± 2 °C, and were aerated two times a week. Finally, the results of the changes in the total petroleum hydrocarbon and microbial activity over time were recorded. A three- parameter sigmoidal function was fitted to the data related to the total petroleum hydrocarbon and microbial activity over time. Analysis of variance was carried out using the SAS software v. 9.0. The leas significant difference method (LSD) was used to compare the means. The changes in the total petroleum hydrocarbons and microbial activity were analyzed using the SigmaPlot software v. 12.5. Microsoft Excel v. 2013 and SigmaPlot v. 12.5 were used to draw the figures. Results: According to the results of the present study, the application of biochar had a significant effect on the reduction of gasoil pollution of the soil. The results related to determination of the kinetic model for the reduction of pollution during the biochar application process showed that the kinetic of reduction in total petroleum hydrocarbon was of first order equation; so that in the first 28 days of the experiment, the rate of total petroleum hydrocarbon degradation was increasing, whereas it decreased 35 days after the beginning of the experiment. Biodegradation constant (k) was higher for the soil treated with the refiner and these soils had a lower half-life compared with the polluted control. The rate of reduction in half-life and Biodegradation constant rate increased with increasing refiner weight. On the contrary, half-life increased and Biodegradation constant decreased with increasing refiner size. The results indicated a significant difference in the traits as a result of applying various sizes and weights of refiner. Weekly monitoring of the pollution degradation and bioremediation performance in all refiner sizes and weights showed that the lowest time to 50% pollutant removal was obtained in 100g kg-1 and 1 mm size treatment. Investigation of the respiration under the mentioned conditions showed that the lower sizes and higher weights of biochar led to improved hydrocarbon degradation. Also, according to the results, biological efficiency (E%) of biochar was calculated 40.05 at the end of the 60 day period.Conclusion: According to the present study, biochar refiner has a great potential for utilization as a cheap and relatively new strategy to eradicate or reduce soil hydrocarbon pollution. This method is compatible with the in situ bioremediation in the soils polluted with petroleum and other petroleum derivate compounds, due to being less costly and posing less hydrocarbon threat to the environment. It is also a suitable tool to devise bioremediation strategies.
Volume 44 - Issue 4
Elham Sadeghi; REZA GHORBANINASRABADI
Abstract
Introduction: Soil microorganisms play an important role in maintaining soil quality through the decomposition of organic matter and nutrients cycling. The quantity of plant residue has a positive effect on the accumulation of organic carbon in the soil. One of the most important problems hampering the ...
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Introduction: Soil microorganisms play an important role in maintaining soil quality through the decomposition of organic matter and nutrients cycling. The quantity of plant residue has a positive effect on the accumulation of organic carbon in the soil. One of the most important problems hampering the release of nutrients from plant residues is the high content of lignocellulose in their structure. Therefore, biological treatment has been considered as a candidate to improve lignocellulosic conversion and more release of nutrients from them. Salinity reduces microbial biomass and decreases their activity in decomposition of soil organic matter and organic matter input into soil. Due to the importance of the role of microorganisms in the storage and release of energy and nutrients in the soil, in recent years, increasing attention has been paid to the estimation of microbial activity and biomass in soil. Therefore, the aim of this study was to study the effect of salinity, inoculation of Pleurotus astreatus and wheat residue on respiration, microbial biomass carbon, organic carbon, carbon availability index and metabolic quotient.Materials and Methods: The experiment was conducted as a completely randomized design with factorial arrangement in three replications under controlled laboratory conditions at Gorgan University of Agricultural Sciences and Natural Resources. Factors included three salinity levels (0, 8 and 15 dS m-1), two fungal levels (0 and 5%) and two wheat residue levels (0 and 1%, w/w). Salinity treatments including (control), 8 and 15 dS m-1 was applied using a mixture of salts (NaCl, KCl and MgCl2 with a molar ratio of 3:2:1). Wheat straw was treated pleurotus fungus and the treated straw was then thoroughly mixed into the soil. To activate the microbial population, soil moisture was adjusted to about 70% of the field capacity and the containers were pre-incubated at room temperature for 2 weeks. The samples were incubated at 25±2°C for 90 days. Microbial biomass carbon, organic carbon was measured at monthly intervals, microbial respiration was measured weekly and substrate-induced respiration (SIR) was measured once at the end of the incubation period.Results and Discussion: The results show that salinity has a negative effect on microbial activity and population, but wheat residues reduce the effect of salinity stress on soil microbial community. Inoculation of Pleurotus into the soil also increased the respiration and microbial biomass. The interaction of wheat residues and Pleurotus on microbial activity in saline soil was greater than their effect alone. According to the results, the simultaneous addition of Pleurotus and wheat residue increases organic carbon (%98), microbial respiration rate (90%), substrate respiration (69%) and microbial biomass carbon (79%) and decreases the metabolic coefficient (6%). Salinity reduced respiration (78%), microbial biomass carbon (81%) and carbon availability index (23%), which indicates a decrease in carbon for microbial activity in saline soils. The lowest and highest microbial activity and biomass were in saline soil (15 dS m-1) not treated with wheat residues and Pleurotus (S2F0R0) and in non-saline soils treated with wheat residues enriched with Pleurotus (S0F1R1), respectively. The results showed that higher salinity level (15 dS m-1) further decreased the measured characteristics including carbon availability index, respiration and microbial biomass carbon compared with 8 dS m-1 salinity level in all treatments. In non-treated soil with wheat residue and Pleurotus, salinity level of 8 dS m-1 reduced MBC by 43, 46 and 44 % compared to control (non-saline) soil. The results showed that there was a significant negative correlation between microbial respiration rate and salinity (P <0.01, r = - 0.87). Salinity reduced microbial respiration rate and the effect of salinity on reducing microbial respiration rate of soil with EC 15 dSm-1 was higher than lower salinity level (8 dSm-1). Also, inoculation of Pleurotus in soil led to increase microbial respiration rate compared with non-treated one. According to the results, salinity levels of 8 and 15 dSm-1 reduced carbon availability index in soil treated with Pleurotus and wheat residue by 18% and 23%, respectively, compared to non-saline soil.Conclusion: The addition of wheat straw enriched with Pleurotus astreatus increased microbial respiration, organic carbon, microbial biomass carbon, substrate-induced respiration and carbon availability index due to the increase of available substrate. Therefore, in saline soils with carbon restriction, increasing the level of organic matter, increased microbial activity and biological potentials in the soil. However, further information on responses of microbial indicators to the joint effect of salinity and Plant residues enriched with other microorganisms is required.ReceivedReceived in revised formAcceptedKey words:Carbon availability index, Microbial biomass carbon, Microbial respiration rate, Soil organic carbon, Substrate-induced respiration
Volume 43 - Issue 4
Ali Khorasani; abdolamir Bosatni
Abstract
Assessment of Irrigation System and Nitrogen Fertilizer Level on Nitrate Distribution in Soil Using Nitrogen-15 Isotope Tracking TechniqueIntroduction: Soil contamination is the presence, diffusion or fusion of foreign matter into the soil, altering its physical and chemical quality in a manner that ...
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Assessment of Irrigation System and Nitrogen Fertilizer Level on Nitrate Distribution in Soil Using Nitrogen-15 Isotope Tracking TechniqueIntroduction: Soil contamination is the presence, diffusion or fusion of foreign matter into the soil, altering its physical and chemical quality in a manner that is harmful to humans, plants and the environment. Soil nitrate pollution due to excessive use of nitrogen fertilizer and inappropriate irrigation causes nitrate accumulation under the active root zone and its movement to groundwater and endangers the environment. By labelling the soil with 15N-labelled nitrate or urea it is possible to trace the fate of fertilizer derived nitrate down the soil profile. This can be achieved by taking sequential by using suction cups to sample the nitrate in the soil solution. The purpose of this study was to investigate the effect of irrigation system and nitrogen fertilizer level on the amount and pattern of nitrate distribution in different soil depths.Materials and Methods: The experiment was conducted in a randomized complete block design with a split plot in two plots and three replications on tomato plant in Agricultural Research Farm of Nuclear Science and Technology Research Institute. Furrow and drip irrigation systems as the main factor and fertilizer treatment (100 and 200 kg N/ha from urea fertilizer source), soil depths (including 15, 30 and 60 cm) and sampling time (Includes 28, 40, 61 and 80 days after plantin) were first, second and third sub-factors respectively. In order to trace nitrogen, CO(15NH2)2 urea fertilizer with enrichment of 4.634% was used. Three soil solution extractors were installed at depths of 15, 30 and 60 cm in each isotopic plot in each replication and extraction was performed 4 times. Soil solution nitrate and 15N/14N isotope ratio were measured by spectrophotometer and mass spectrometer respectively. Results and Discussion: The highest soil nitrate-N (N-NO3) concentration(94.31 mg L-1) in furrow irrigation (Fertilizer level of 200 kg N ha-1, soil depth of 60 cm and third time of soil solution sampling) and its lowest concentration(1.73 mg l-1) in drip fertigation system (fertilizer level of 100 kg N ha-1, soil depth of 60 cm and fourth time of soil solution sampling) was observed. The results showed that the concentration of nitrate-N in the drip fertigation system was higher at a depth of 15 cm (active root depth) than at depths of 30 and 60 cm. The highest concentration of nitrate nitrogen derived from the source of nitrogen-15 (N-15NO3 dff)(88.82 mgl-1) in furrow irrigation (Fertilizer level of 200 kg N ha-1, soil depth of 60 cm and third time of soil solution sampling) and the lowest concentration (0.12 mgl-1) in drip irrigation fertilizer (fertilizer level of 100 kg N ha-1, soil depth of 30 cm and second time of soil solution sampling) was observed. Nitrate-N concentration derived from labeled fertilizer source in furrow irrigation at a depth of 60 cm (below the active root depth in furrow irrigation) was greater than the depths of 15 and 30 cm. the results also showed that The highest concentration(42.25 mgl-1) of nitrate-N derived from soil source in drip fertigation system (fertilizer level of 200 kg N ha-1, soil depth of 15 cm and first time of soil solution sampling) and the lowest concentration (0.29 mgl-1) in drip fertigation system (100 kg N ha-1, soil depth of 60 Cm and the fourth time of soil solution sampling) was observed.Conclusion: The results showed that of the total nitrate nitrogen in the 0-60 cm depth, the values (62, 29 and 9%) in the drip and (10, 34 and 56%) in the furrow irrigation system in Depths of 15, 30 and 60 cm were observed respectively. Nitrogen-15 data showed that of the total soil nitrate nitrogen, the values of 20 and 80 percent in fertigation system and 77 and 23 percent in furrow irrigation system was observed from labeled fertilizer and soil source, respectively. increasing nitrate accumulation was observed in soil depth of 60 cm with increasing nitrogen application in furrow irrigation. The use of fertigation system was effective to prevent nitrogen loss from the active root zone of the plant. In general, fertigation system and fertilizer level of 100 kg N ha-1 was the best irrigation method and the best fertilizer level to reduce nitrate leaching losses in the conditions of this study.
Volume 35 - Issue 1
E. Askari asli ardeh; Z. Basati; A. Mohseni manesh
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 32 - Issue 1
M.A Salehi; N. Khademol Hosseini; M. Almasi
Volume 33 - Issue 1
Volume 36 - Issue 1
Atefeh Dashtbozorg; Gholamabbas Sayyad; Iraj Kazeminezhad; Mousa Mesgarbashi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 65-75
Abstract
Superabsorbent polymers are water containers that absorb and retain large quantities of water when applied to the soil. These materials release the absorbed water, allowing the plants to consume adequate amounts of water at all growth stages. One of the best options for increasing the irrigation efficiency ...
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Superabsorbent polymers are water containers that absorb and retain large quantities of water when applied to the soil. These materials release the absorbed water, allowing the plants to consume adequate amounts of water at all growth stages. One of the best options for increasing the irrigation efficiency and better application of precipitation in arid and semi-arid areas are application of superabsorbent polymers to soil. Different sizes of particles of a superabsorbent polymer were compared on the soil water retention capacity. The study adopted a factorial experimental design based on a completely randomized design in loamy sand and clay loam soil with three replications. There were 7 treatments of water absorbent material including control (without the water absorbent material) and superabsorbent Taravat A200 in 6 sizes (0.21-0.25, 0.25-0.5, 0.5-1, 1-2, 2-3.4 and 3.4-4.75 millimeter, each at 2g per kg soil). Then soil water content was measured for each treatment at suctions 0, 0.1, 0.3, 0.5, 1, 3, 5 and 15 bar and the soil moisture curves were plotted separately. The results showed that there was a significant difference among treatments and two soil textures in various suctions and the interaction of these factors at the level of %1. Also, it was observed that the superabsorbent polymer 1-2 mm compared with other treatments resulted in increase the soil water holding capacity, significantly especially in the light soil texture.
Volume 34 - Issue 1
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 65-74
Abstract
Maintenance plays an important role in sustaining the reliability, availability, product quality, reducing risk, increasing efficiency and security. Hence being aware of maintenance costs and also replacement age of machines seems necessary. In this research the costs of repair and maintenance related ...
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Maintenance plays an important role in sustaining the reliability, availability, product quality, reducing risk, increasing efficiency and security. Hence being aware of maintenance costs and also replacement age of machines seems necessary. In this research the costs of repair and maintenance related to 24 AUSTOFT 7000 sugarcane harvester, being used in Imam Khomeini agro-industry co., has been studied. The research was carried out by collecting the costs of spare parts, wages paid for repairs, lubricant, grease and filters and also rate of annual functions of harvesters. Comparing the shares of components maintenance costs showed that spare parts play the most important role in repair costs six various mathematical models were tested by using computer software, in order to choose a suitable mathematical model, and finally a quadratic model was selected. The replacement age diagram, drawn by using amortization cost digits, capital interest, insurance and accumulated repair and maintenance costs showed that none of the machines had reached the replacement age until the year of research study. Therefore, replacement age of harvester was estimated to be between 9 and 11 years, by using the selected mathematical model and estimating the repair costs up to fifteenth life year of the machine.
Volume 37 - Issue 1
Soil Chemistry and Pollution
K. Dalvand; A. Eftekhari
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 67-75
Abstract
Cadmium (Cd) is a heavy metal that is uptaken by plants, accumulates in edible parts of plants and negatively impacts human health. This study was conducted to investigate the uptake and accumulation of Cd in different parts of reddish. The experimental design was a factorial with complete block design ...
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Cadmium (Cd) is a heavy metal that is uptaken by plants, accumulates in edible parts of plants and negatively impacts human health. This study was conducted to investigate the uptake and accumulation of Cd in different parts of reddish. The experimental design was a factorial with complete block design using three levels of Cd (0, 30 and 60 mgkg-1) and two dates of harvesting (commercial maturity and one week after commercial maturity, called 1st and 2nd dates of harvesting) with three replications. The experiment was carried out using pots which were inserted at research farm of Shahid Chamran University of Ahwaz. Results indicated Cd accumulation in different parts of reddish as the Cd concentration rates increased. The highest Cd accumulation was in the roots (79.35 mg kg-1) at the 2nd date of harvesting. The maximum Cd accumulated in hypocotyls (36.0 mg kg-1) at the 1st date of harvesting, hypocotyls skin (45.0 mg kg-1) at the 1st date of harvesting, and leaves (95.4 mg kg-1) at the 2nd date of harvesting when 60 mg kg-1 of Cd was applied. The results also showed that Cd treatment maximizes Cd at the 1st date of harvesting and increases over the second time of harvesting in reddish organs. The order of Cd accumulation from the highest to the lowest concentration was leaves, roots, petioles, hypocotyls skin and hypocotyls.
Volume 33 - Issue 2
Volume 36 - Issue 2
Sajedeh Sadinejad; Ali Jafarnejadi; Ali Gholami; Abdolamir Moezzi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 69-80
Abstract
One of the basic principles for sustainable production is improving the quality of soil with regard to soil fertility and soil nutrients status. This study was conducted to investigate spatial variation of copper and manganese elements in soil farms in the northern part of Khuzestan region (100,000 ha). ...
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One of the basic principles for sustainable production is improving the quality of soil with regard to soil fertility and soil nutrients status. This study was conducted to investigate spatial variation of copper and manganese elements in soil farms in the northern part of Khuzestan region (100,000 ha). Therefore, 95 soil samples were collected from studied regions according to their wheat cultivation area. The data were analyzed to determine spatial variation and interpolation using Kirging technique. The results revealed that the average soil manganese concentration was 6.75 mg/kg in the study regions. Also, more than 75% of studied soils had manganese concentrations less than 8 mg/kg (threshold value), the average of copper concentration was 1.35 mg/kg, and about 90% of soils had desirable copper concentration. According to the results, there were significant correlations between the soil's copper and phosphorus (r= 0.79*), clay (r= 0.78*) and salinity (r= 0.77*) and also between soil's manganese and pH (r=0.83*). The best model for study characteristics was the spherical model. The highest soil manganese concentration was on the northeast, and the highest soil copper was on the west of the study regions. Finally, in some parts of the study area in which manganese and copper levels were less than the threshold value, application of copper and manganese fertilizers can be recommended. It increases the yield and improves the soils and agricultural products quality.
Volume 34 - Issue 2
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 69-84
Abstract
To study the effects of irrigation water salinity, nitrogen, and foliar application of calcium chloride on yield and growth indices of pepper, a factorial pot experiment was carried out in Znajan Agricultural Research Center in 2010 using a completely randomized design and three replications. In this ...
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To study the effects of irrigation water salinity, nitrogen, and foliar application of calcium chloride on yield and growth indices of pepper, a factorial pot experiment was carried out in Znajan Agricultural Research Center in 2010 using a completely randomized design and three replications. In this experiment, four levels of nitrogen (0, 75, 150 and 300 mg/kg), four levels of salinity (0.7, 1.5, 3 and 6 dS/m) and two levels of foliar spray (with and without spray) were used. Analysis of variance showed that the effects of salinity were significant on yield, number of fruit, length and diameter of fruit, dry weights of root, plant height and dry weights of leaf and fruit, and these parameters decreased as the salinity levels increased. Yield and growth indices of pepper plant increased as the nitrogen levels increased, but fruit length and diameter were not affected by nitrogen application. Foliar application of calcium chloride was not effective on growth indices of pepper under saline conditions. But interactive effects of salinity and nitrogen was significant on plant yield. When the salinity levels of treatments were 0.7 or 1.5 dS/m, the plant yield increased as the nitrogen levels increased. However under the salinity levels of 3 dS/m, the plant yield increased when the nitrogen levels did not exceed 150 mg/kg. At higher salinity level (6 dS/m), application of nitrogen decreased the plant yield as compared to control.
Volume 39 - Issue 2
A Ardeshiri Lajimi; R Ghorbani Nasrabadi; M Barani Motlagh; S A Movahedi
Volume 35 - Issue 2
Farideh Yarahmadi; Ahmad Landi; Mohammad Asoodar; Adel Moradi Sabz Kuhi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 71-82
Abstract
Increasing the concentrations and emissions of greenhouse gases makes the weather warmer and affects land uses. Carbon dioxide emission is recognized as one of the most important factors in global warming. The objectives of this research were to investigate the amount of CO2 emission from soil to atmosphere ...
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Increasing the concentrations and emissions of greenhouse gases makes the weather warmer and affects land uses. Carbon dioxide emission is recognized as one of the most important factors in global warming. The objectives of this research were to investigate the amount of CO2 emission from soil to atmosphere during the wheat growth under two different tillage and irrigation methods. In this study, an experiment with a combination of tillage practices (conventional and conservation tillage) and two irrigation practices (flooding and furrow irrigation), using 45% surface residue, with 6 times of sampling from soil gases and 3 replications was done. The Statistical design of split plot in time with covariance analysis was used. A closed chamber method and gas chromatography were applied at Ramin Agricultural University research station. In order to measure the amount of water used, the submerged siphon method was used. The results showed that, the overall carbon gas emissions were influenced by soil moisture and tillage systems. Conventional tillage systems caused more fluxes because of mixing soils, the increase for CO2, was 67%. The amount CO2 gas emission for the flooding system was 33% more than of that furrow irrigation. Conservation tillage with furrow irrigation produced the lowest (p≤0.05) carbon dioxide emission. This value was 1143 mg/ m3 whereas the conventional tillage-flood irrigation, with an average of 2592 mg/m3 showed the maximum (p≤0.05) emission.
Volume 37 - Issue 2
Soil Biology, Biochemistry and Biotechnology
A.R. Fallah Nosratabad; S. Momeni; S. Shariati
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 73-86
Abstract
The present investigation was designed to compare the effect of combination biofertilizer of nitrogen fixing free-living bacteria and plant growth promoting bacteria of Azotobacter. It also aimed to compare the effect of Azospirillum alone and in combination with other plant growth promoting bacteria ...
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The present investigation was designed to compare the effect of combination biofertilizer of nitrogen fixing free-living bacteria and plant growth promoting bacteria of Azotobacter. It also aimed to compare the effect of Azospirillum alone and in combination with other plant growth promoting bacteria of Pseudomonas fluorescens and Bacillus subtilis with five nitrogen fertilizer levels on the wheat growth indices and yield.The experiment including biofertilizer and different amounts of nitrogen fertilizer was carried out as factorial in completely randomized design with three replications. At the end of plant growth period, some plant indices such as spike and grain number, crop yield, grain to straw weight ratio, straw yield, and grain nitrogen percentage were measured. The results showed that in the simple effect of bio fertilizer, the most effective factor was related to the biofertilizer consortium containing Azotobacter, Azosprillum, Pseudomonas and Baillus subtilis which respectively increased 8, 22.5, 26.5 and 23.3 % the amounts of grain nitrogen, spike number, straw yield and plant yield in comparison with control treatment. Although in the simple effect of chemical fertilizer on studied indices, 100 kg/ha of nitrogen had the most effect, it didn’t demonstrate any significant difference in comparison with the fertilizer level of 75 kg/ha. The highest amounts of measured indices were related to the interaction of bio fertilizer including Azotobacter, Azosprillum, and Pseudomonas and Bacillus subtilis with nitrogen level of 75kg/ha that could respectively increase 25, 100.4, 53.5, 100.6 and 92.6% of grain and spike number, the nitrogen content of grain, straw and plant yield compared to control plant.
Volume 41 - Issue 1
Plant Nutrition, Soil Fertility and Fertilizers
Abstract
Introduction: Shortage of non-saline and high quality irrigation water is a serious problem in agricultural farms which limits crop productions. Proper nutrient management is one of the key solutions to decreasing the adverse effects of salinity. Zinc is an essential trace element that can alleviate ...
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Introduction: Shortage of non-saline and high quality irrigation water is a serious problem in agricultural farms which limits crop productions. Proper nutrient management is one of the key solutions to decreasing the adverse effects of salinity. Zinc is an essential trace element that can alleviate the negative effects of toxic ions on plant growth under the saline environments. Therefore, in this study, the effect of zinc an enhancer agent of saline irrigation water of wheat farms was investigated. Materials and Methods: A factorial experiment was conducted based on randomized completed block design with four replications. The Experiment was under the greenhouse condition located in Borazjan Research Institute of Agriculture and Natural Resources during 2012-2013. The first factor comprised four levels of salinity including 4 (control), 8, 12 and 16 dS.m-1. The second factor was application of four levels of zinc including 0, 10, 20 and 30 mg.kg-1 soil. Results and Discussion: Our results suggested that increase in zinc concentration could significantly alleviate negative effects of salinity stress on plant height. The highest plant height (84.13 Cm) was achieved by application of 30 mg.kg-1 soilzinc. Although increase in salinity stress reduced wheat growth potential there was no significant difference between 4 dS.m-1 (86.32 Cm) and 8 dS.m-1 (80.19 Cm) on the plant height. The lowest number of grain in spike (36.19) was observed in control treatment while the maximum number of grain in spike (53.44) was produced under 30 mg.kg-1 soil zinc. Increase of salinity from 4 to 16 dS.m-1 drastically reduced the number of grain in spike from 50 to 39.69. Application of 30 mg.kg-1 soilzinc resulted in higher RWC (85.02%) compared to control (69.30%). Increase in zinc concentrations led to a higher chlorophyll and carotenoid content. There was no significant difference between 10 and 20 mg.kg-1 soilzinc sulfate on chlorophyll content. Increasing salinity from 4 dS.m-1 to 12 dS.m-1 resulted in reduction of chlorophyll a from 2.58 to 2.08 mg.gr-1 fw, chlorophyll b from 0.79 to 0.59 mg.gr-1 fw and total chlorophyll from 3.76 to 2.90 mg.gr-1 fw. Zinc promoted synthesis of carotenoid. Carotenoid contents reached 8.43 mg.gr-1 fw by the application of 30 mg.kg soil-1. The maximum carotenoid content (9.30 mg.gr-1 fw) was observed at 8 dS.m-1 salinity while there was no significant difference with carotenoid content of 4 dS.m-1 (8.99 mg.gr-1 fw). However, by increasing salinity stress, the carotenoid content significantly reduced and the lowest carotenoid content (6.70 mg.gr-1 fw) was observed at 16 dS.m-1 salinity. Zinc content of leaf and grain of wheat significantly increase by the application of 30 mg.kg-1 soil zinc and in the highest concentration of fertilizer, zinc content of leaf and grain reached 32.07 and 63.76 mg.kgr-1 respectively. The highest wheat biological yield (1577.50 g.m-2) was observed in 4 dS.m-1 with 30 mg Zn kg-1 soil while the lowest biological yield (986.39 g.m-2) was observed at no added fertilizer and salinity of 16 dS.m-1. The maximum wheat grain yield (692.03 g.m-2) was observed in salinity of 4 dS.m-1 with 30 mg Zn kg-1 soil while the lowest grain yield (459.39 g.m-2) was observed at no added fertilizer treatment and salinity of 16 dS.m-1. Our results clearly proved that application of zinc could alleviate negative effects of salinity stress on wheat grain yield. Wheat biological yield at salinity of 16 dS.m-1 with no added fertilizer reached 986.39 g.m-2 while at the same salinity, application of 30 mg Zn kg-1 soil zinc enhanced biological yield to 1131.80 g.m-2. Although salinity level from 4 to 16 dS.m-1 significantly reduced wheat grain yield application of 30 mg.kg-1 soil zinc increase grain yield from 459.39 g.m-2 to 506.94 g.m-2 in 16 dS.m-1 salinity. Conclusion: Wheat yield was significantly affected by the quality of irrigation water. The higher the concentrations of salinity, the lower wheat yield will be produced. However, our results revealed that application of zinc is an effective way of reducing salinity to restrict wheat grain yield. This trace element enhances plant production of photosynthetic pigments; therefore, physiological performance of the crop was improved under saline conditions. Application of 30 mg Zn kg-1 soil was highly recommended in farms with saline irrigation water.
Volume 41 - Issue 3
Post Harvesting Technology
Mohammad Rasool Afifi; Yaghoob Mansoori; hassan zaki dizaji; Gholamreza Akbarizadeh
Abstract
Introduction Date fruit is a strategic horticultural product in the Middle East that plays an important role as an economic product to develop exports. Iran is the second world producer that contains 14% production of date fruit in the world and has a high potential in order to ideally exploit this valuable ...
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Introduction Date fruit is a strategic horticultural product in the Middle East that plays an important role as an economic product to develop exports. Iran is the second world producer that contains 14% production of date fruit in the world and has a high potential in order to ideally exploit this valuable product. Condidering the low price of Iran's exported dates due to poor preparation and packaging process it is necessary to use new technologies for classification and grading of them. The application of machine vision in agriculture has increased considerably in recent years.There are many fields in which computer vision is involved in order to develop precision agriculture. Machine vision systems by elimination of manual inspection in the field of postharvest technologies improve accurate and uniform quality control of agricultural products. In most of these applications, the method of image analysis for product categories, with the determination of some external features such as color, size, shape, and surface texture has been used (Blasco et al., 2012). Alohali used RGB images taken from Date fruits and defined a set of qualitative external features of dates and categorized them into three categories in terms of quality. One of the characteristics of the soft tissue was detected using color intensity distribution. The final precision of carefully designed system using a propagation neural network was 80% (Alohali, 2011). The size is a particular aspect of external appearance of fruits and vegetables; the price of agricultural products is usually related with their size; therefore, grading of fruits and vegetables into different size groups of size is always necessary in the postharvest handling and processing stages (Zhang et al., 2014). Texture is the other significant sensory quality attribute that has been frequently used in the external quality inspecting and grading systems for the agricultural product quality evaluation. Texture is closely related to some internal quality of fruits and vegetables, such as maturity and sugar content. Therefore, texture is one of the widely used indicators the consumer uses for quality assessment of fruits and vegetables. Texture analysis can also play an important role in defect recognition and segmentation in grading systems due to its powerful discriminating ability (Lee et al. 2008). Materials and Methods The current study examined image processing technology for grading Zahedi cultivar dates in Khuzestan province. Each date fruit was placed under the camera and imaged. At the same time, the samples were classified by an experienced grader. Imaging was conducted in a lighting box to avoid the effects of ambient light. Capturing images was done by a digital camera using CCD sensor. External features of dates such as color, size, shape and surface texture were extracted by image processing methods using MATLAB software (Version R2013a, The Mathworks Inc., Natick, MA, USA). Eleven size and shape features, nine color features, and six external texture features were extracted. The features which led to better separablity for classification were selected using stepwise discriminant analysis (SDA). Selecting the best features is effective to increase accuracy and speed of the algorithm. Two methods of learning machine were used for final classification: discriminant analysis that is a statistical technique and neural networks (ANN). Discriminant analysis method and Neural networks were implemented in SPSS 22.0 and neurosolution 7.0 software respectively. Results and Discussion The best channel to separate dates from background was identified by comparison of the histogram of 9 channels from RGB, HSI and Lab color spaces. The histogram graph, which has more breakdown in the range of intensities, is more suitable to apply thresholding operation because it has a good contrast with the background. Channel B from RGB color space was chosen to segment dates from background. Channel of B has a better contrast between the color channels and also its corresponding histogram intensity values led to the best separability. Five features of size and shape, three features of color and three features of external texture were selected by SDA method to reduce dimension of features space. Degrees marked from 1 to 3 for qualitative grading and sorting by size define levels of quality and determine size from big to small dates respectively. According to table 4, accuracy of classifications for grading, sorting by size and inspection of wrinkled date fruits from healthy ones were 93.6%, 94.4% and 90% respectively. Classifications by MLP neural networks were done. The most important factor for evaluation of neural networks is Correct classification rate (CCR%). The results based on CCR from Confusion matrix is reported in table 5. Accuracy of classifications for grading, sorting by size and inspection of wrinkled date fruits from healthy ones using ANN were 95.7%, 92.3% and 93.8% respectively. Conclusion Final accuracy of classification using discriminant analysis and neural network was achieved 92.7% and 93.9% respectively. Results show relative superiority of neural networks over statistical methods due to its accuracy. According to high accuracy of classification using learning machine methods, it can be concluded that using image processing algorithm was successful in extracting external features for sorting and grading of dates.
Volume 42 - Issue 4
L. Rasoli; K. Nabiollahi; R. Taghizadeh Mehrjardi
Abstract
Introduction Rapid population growth in developing countries implies that more food will be required to meet the demands of this population. Wheat as one of the most important grain crops in the world is a great source of food for human which is planted under a wide range of environments and its production ...
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Introduction Rapid population growth in developing countries implies that more food will be required to meet the demands of this population. Wheat as one of the most important grain crops in the world is a great source of food for human which is planted under a wide range of environments and its production influences on local food security. The production of wheat per unit area in Iran is low compared to developed countries in the world. One of the main causes for this low yield is that the suitable land for planting has not been recognized. Therefore, to overcome this problem, land suitability assessment is needed, which can help to increase crop yield. The first step in agricultural land use planning is land-suitability assessment which is often conducted to determine which type of land use is suitable for a particular location Digital mapping approach have been applied to link between soil observations and auxiliary variables to understand spatial and temporal variation in soil class and other soil properties. Little attempt has been made for using Digital mapping approach to digitally map land suitability classes Therefore, this paper applied land suitability assessment framework and digital soil mapping approach to map land suitability for rain-fed wheat in Kurdistan province. Materials and Methods The study area is located in Kurdistan Province, western Iran. It surrounds the city of Ghorveh and covers a region of 6500 ha. The climate is semi-arid whose features can be performed using a cold and rainy winter and a moderate and dry summer. The mean yearly rainfall is 369.8 mm and over 90% of the rain falls between November and March. The mean temperature (10.8℃) is relatively cool. Soil moisture and temperature regimes are Xeric and Mesic, respectively. The physiography units include piedmont, fan, hills, and mountain and slope varies from gentle to very steep. At first land unit component map was prepared by Mahler physiography method, then, 17 representative profiles in each land unit component were dug and described. 105 auger samples also were taken at three depths (0-20, 20-50 and 50-100 cm). Soil texture, acidity, organic carbon, CaCO3, gypsum, ESP, electrical conductivity and gravel were measured in all soil samples. Topography and climate data were also recorded. Numeric ratings of soil, topography and climate parameters based on land requirements of wheat were determined and land suitability index using parametric method were calculated. Then land suitability classes of wheat were determined. A set of auxiliary variables (i.e. land unit component, terrain attributes and remotely sensed data) to predict land suitability classes of rain-fed wheat. In order to generate land suitability class map, artificial neural network were applied to make relation between auxiliary variables and land suitability classes. Results and Discussion The results showed that the area has about 36.61% N2 class, 40.32% N1 class and 22.53% S3 class. The validation results of the model based on the statistical indices including root mean square error, mean error, and determination coefficient (6.56, 4.81, 0. 68, respectively), indicates that the artificial neural network model has suitable accuracy. Auxiliary data including MrVBF index, LS factor, MRRTF index, slope, Land unit component, VDCN and band 2 were the most important for prediction of wheat land suitability index in digital method. The major limitation of the study area to plant rain-fed wheat were rainfall in the flowering stage, sever slope, shallow soil depth, high pH and gravel. Therefore, to increase production and sustainable agricultural system it is suggested land improvement operations such as terracing, decreasing pH, supplementary irrigation and gathering gravel. The highest values of rain-fed land suitability index were observed in the units physiographic of river plain and plateau, while the lowest value were observed in the units physiography of mountain and hill which had high slope, shallow soil and high gravel. These results were confirmed by one-way ANOVA and Duncan tests. Conclusion Based on the results of statistics indices artificial neural network had suitable accuracy for predicting land suitability index of wheat. In general, the study area, because of limitation of sever slope, shallow soil, high pH, and gravel, has low land suitability index for rain-fed wheat. Hence, to improve land suitability of the study area and increasing its production, suitable land improvement operations is required.
Volume 38 - Issue 2
M. Hashemi; A. Gholamalizadeh Ahangar; A. Shabani
Volume 38 - Issue 1
L Naderloo; R alimardani; M Omid; F Sarmadian; H Javadikia; M. Y Torabi
Abstract
Introduction: Social, technical and economic factors in addition to environmental, soil and climate factors affect crop yield and cultivation. This study was implemented to know the impact of age, experience and literacy level of farmers as social factors and access to water supply, roads, silo, labor, ...
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Introduction: Social, technical and economic factors in addition to environmental, soil and climate factors affect crop yield and cultivation. This study was implemented to know the impact of age, experience and literacy level of farmers as social factors and access to water supply, roads, silo, labor, tractors and machinery and conservation tillage as technical-mechanization factors on crop yield. Fuzzy rule-based inference system converts the complex decision-making problems to the smaller criteria and makes easier the multi-criteria evaluation process. So we decided to use fuzzy approach to modeling the social and technical-mechanization indices. The main disadvantage of fuzzy systems is their inability to learn. So, the optimization of fuzzy systems is the most important step in its implementation. Genetic algorithm (GA) approach is used as a complementation of fuzzy model to optimize fuzzy rules. One method to optimize the fuzzy rules is Pittsburgh method in GA. In this method, one gene is used for every rule and the gene value finds out the rule.The kind of membership function will have a great impact on the result. The kinds of membership function for fuzzy sets involve triangular, trapezoidal, generalized bell, Gaussian, Gaussian combination, Sigmoidal, product of two sigmoidal, difference between two sigmoidal, Π, Z and S shapes. The objectives of this study are: 1- providing two fuzzy models for the social and technical-mechanization indices for wheat production 2- optimizing the fuzzy rules and the type of membership function for the fuzzy set. Materials and Methods: Fuzzy toolbox of MATLAB software ver. 7.8.0 (R2009a) was used to design fuzzy model. Fuzzy inference system (FIS) used in this study was Mamdani type that is based on if-then rules. The age, experience and literacy level of farmers were selected as input data for fuzzy social model. Access to water supply, roads, silage, labor, tractors and machinery and conservation tillage equipment were selected as input data for fuzzy technical-mechanization model. Mamdani fuzzy inference system was used to design models. Fuzzy rules were written by a mechanization expert knowledge. To correct written rules, the method of Pittsburgh in GA was used to optimize the fuzzy rules for all FISs. Then, a program was written in MATLAB software to get the best combination of membership functions to achieve the best result. The program tested 24 kinds of combined membership functions for medial and side fuzzy sets of input variables. The result was the best when the relationship between obtained index and crop yield had the highest value of the correlation coefficient (R2), minimum value of mean square error (MSE) and mean absolute error (MAE). So the fuzzy-GA model will produce the social and technical-mechanization indices while the fuzzy rules of model have been optimized and the best combination of membership functions has been selected. Results and Discussion: The coefficients of determination were obtained 0.11 for fuzzy social model and 0.51 for technical-mechanization model before optimization of fuzzy rules. The error of fitness function decreased with rising generation numbers of GA until the best answer was obtained. After optimization of fuzzy rules by genetic algorithm, these values increased to 0.50 and 0.71 for the fuzzy social and technical-mechanization models, respectively. This result showed that optimizing the fuzzy rules had a significant impact on results of models. After implementation of the written program, to select the best type of membership functions for fuzzy input variables, coefficient of determination varied from 0.14 to 0.51 and 0.1 to 0.73 for the fuzzy social and technical- mechanization models, respectively. This result showed that the effect of social factors on wheat yield was less than technical-mechanization factors and yield can be predicted by technical-mechanization factors with more accuracy than social factors. In the social model for input of experience, the lowest MSE and the highest R2 belong to a FIS with three fuzzy sets and S, Π and Z-shaped membership functions for the right, medial and left fuzzy sets, respectively. In the technical model for input of road availability, the lowest MSE and the highest R2 belong to a FIS with three fuzzy sets and s, trapezoid and z- shaped membership functions for the right, medial and left fuzzy sets, respectively. These results showed that the type of membership functions for fuzzy sets had considerable importance for the accuracy of the model. Conclusion: It can be concluded that the accuracy of the fuzzy model with optimized rules by GA and the best type of membership function for fuzzy sets are considerable. Effect of technical-mechanization factors on wheat yield was more than social factors. This result also showed the strength of fuzzy–GA method in modeling of such issues.
Volume 42 - Issue 3
A. Rahimi; B. Doulati; S. Heydarzadeh
Abstract
Introduction Lamiaceae, formerly called Labiatae, the mint family of flowering plants with 236 genera and more than 7,000 species, the largest family of the order Lamiales and many species are cultivated for their fragrant leaves and attractive flowers. Thymus daenensis is native to Iran and growing ...
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Introduction Lamiaceae, formerly called Labiatae, the mint family of flowering plants with 236 genera and more than 7,000 species, the largest family of the order Lamiales and many species are cultivated for their fragrant leaves and attractive flowers. Thymus daenensis is native to Iran and growing in many parts of Iran, the plant is extensively used in folk medicine and has a wide variety of essential oils. Medicinal and aromatic plants have antioxidant compounds such as polyphenols which decrease oxidative stress in cells of plants and animals. In recent decades, excessive use of chemical fertilizers in order to increase the yield of agricultural products has caused many problems in economic and environmental aspects. The biofertilizer plays an important role in nitrogen fixation, iron sequestration, and phosphate solubilization, thus making these complex organic molecules available for utilization by the plants. Biofertilizers are the microbial inoculants that colonize the rhizosphere and improve plant growth by enhancing nutrient accessibility to plants. However, biofertilizers perform more than one mechanism for accomplishing plant growth enhancement. These abilities are of great agriculture importance as far as crop yield and soil fertility improvement is concerned, thus decreasing the ill effects of chemical-based fertilizers in our environment. For instance, excessive use of chemical N fertilizers causes soil acidifcation and, thus, groundwater and atmospheric pollution. Nonetheless, synthesis of chemical fertilizers is highly energy-consuming processes. Chemical based fertilizers impose long-lasting effects on the atmosphere in terms of carbon footprint, eutrophication, and soil fertility decline. However, the control of chemical and biological properties of soil is important in the quantity and quality of agricultural crops. Few reports reveal that in case of controlled soil conditions, signifcant enhancement in crop production was achieved through biofertilizer applications. Thus, this research was carried out with the aim of studying the effect of independent and combined use of biological and chemical fertilizers on quantitative and qualitative properties of thyme. Materials and Methods The aim of this study was to investigate the effect of biofertilizers (phosphate Barvar-2 and Azotobacter), manure (cow manure), and chemical (NPK) on quantitative and qualitative characteristics of Thymus daenensis. Physicochemical properties of study soil (calcium carbonate equilibrium, pH, OC, EC, micro and macro elements, soil texture) and was determined by standard methods. A factorial experiment based on randomized completely design was carried out with eight treatments including chemical fertilizer (100%), biofertilizers (phosphate Barow-2 and Azotobacter) (100%), cow manure (100%), combined treatment: chemical + biofertilizer 50%, chemical + cow manure 50%, biofertilizer,+ cow manure 50%, biofertilizer + chemical + cow manure 50% and control at three replications. Seeds of Thymus daenensis were treated before cultivate with biofertilizers (phosphate Barvar-2 and Azotobacter) with 100 g ha-1 based on the recommended guidelines (10^8 active bacteria g-1 of biofertilizer). Seeds were cultured in perlite and pit moss culture beds. Transplant was transmitted to the farm at the end of April. Thymus product was harvested at flowering stage. Economic performance of thymus including leaf and inflorescence weight was calculated after drying of bushes. Essential oil content was measured using clevenger. Physiological and antioxidant propertiese including chlorophyll a and b, total chlorophyll, cartenoids, total phenolic content and flavnoieds were measured (Lichtenthaler and Wellburn, 1987; Horwist, 1984). Essential oil yield was obtained from essential oil percentage in dry matter yield of thymus. Results The results showed that the integrated application of biofertiliizers was significant in qualitative and quantitative characteristics of Thymus daenensis. Based on the results, shoot dry yield (156.26 g m-2), essential oil yield (5.36 g m-2) and economic yield (74.72 g m-2) in 50% chemical fertilizer + biofertilizer + cow manure treatment were higher as compared to other treatments. Integrated application of organic and chemical fertilizers improved the content of photosynthetic pigmentation and increased the concentration of iron (Fe), zinc (Zn) and copper (Cu) in thymus. Aso, combined application of 50% chemical fertilizer + biofertilizer + manure increased total phenol (30.12%), flavonoids (22.26%) and antioxidant activity (15.95%) of thymus compared to control treatment. Conclusion The results showed that the chemical fertilizers to start production and compensate for the fertilizer source and biofertilizers for the continuous of the presence of nutrients in soil are important. Consequently, the combination of chemical fertilizer (NPK) and biofertilizers could be recommended as a suitable nutrition source for plant as well as the improvement of soil physical and chemical properties. Accordingly, chemical fertilizers consumption are hazardous for human severely affect ecological balance in the environment. Therefore, the success related to biofertilizers depends on inventions of innovative strategies which are related to the functions of different beneficial bacteria and their proper application to the fields through advanced and improved techniques.
Volume 39 - Issue 1
I. Fazeli Farsani; M. H. Salehi; A. A. Besalatpour; M. R. Farzaneh
Abstract
Introduction In order to achieve sustainable management of water resources, integrated knowledge of water resources and modeling is essential, especially in arid and semi-arid regions where water resources have become scarcer with increasing demands from socioeconomic development and population growth. ...
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Introduction In order to achieve sustainable management of water resources, integrated knowledge of water resources and modeling is essential, especially in arid and semi-arid regions where water resources have become scarcer with increasing demands from socioeconomic development and population growth. In recent years, utilization of hydrological models has been increased to simulate watershed processes for cost saving purposes. Various hydrological models such as soil and water assessment tool (SWAT) have been developed to simulate runoff in the watersheds. In this study, SWAT was used to simulate monthly runoff in Bazoft watershed and the impact of springs discharge on the simulation accuracy was evaluated. Materials and Methods Bazoft is one of the watersheds in Karun basin, (31° 37′ to 32° 39′ N and 49° 34′ to 50° 32′ E) located in northern part of the Karun river basin in southwestern Iran. The area of the watershed is 2168 km2. The main river in the watershed is Ab Bazoft which is joined by the Karun River at the outlet of the watershed. The elevation ranges from 880 m in the south of the watershed to 4200 m on Zardkuh Mountain in the north eastern area. Because the topography is very high in the watershed, the rainfall distribution is different, the average of rainfall in the northern part of the watershed is 1400 mm, while the southern part is 500mm. SWAT was used because the model is a continuous time, spatially and semi-distributed and basin-scale model, in which hydrological processes and water quality are coupled with crop growth and agricultural management practices. Input data include digital Elevation Model (DEM), land use, soil type, meteorological and hydrological observed data were provided. After running the model, a sensitivity analysis was done using the one at time method and SUFI-2 program. For calibration and uncertainty analysis in this study, we used the PSO (particle swarm optimization) algorithm. SUFI-2 and PSO are linked to SWAT in the environment of SWAT-CUP software. We used about two-third of the observed data for calibration and the remaining for validation. The simulation period was from 1992 to 2008. The study period was 1998–2008 for calibration and 1992–1997 for validation. The calibration and validation period results were analyzed at monthly time scale. ). The objective function was the Nash– Sutcliffe coefficient. Two indices, the P-factor and the R-factor, are used to quantify the goodness of calibration performance. The P-factor is the percentage of data bracketed by the 95PPU band, and ideally we would like to bracket all measured data, except the outliers, in the 95PPU band, and the R-factor is the average thickness of the 95PPU band divided by the standard deviation of the corresponding measured variable. Theoretically, the value of P-factor ranges between 0 and 100%, while that of R-factor ranges between 0 and infinity. In ideal conditions when the uncertainty model is perfect, P-factor will be 1 and the R-factor will be 0. Results and Discussion The results showed that the simulated base flow, peak flow, and hydrograph trend by entrance of spring discharge data to the model were more in agreement to the observed runoff data than the model with no spring discharge data. Therefore, the constructed model with the spring discharge data was selected to calibrate the particle swarm optimization (PSO) algorithm. In the sensitivity analysis, the parameters of curve number for moisture condition II (CN2), groundwater delay time (GW_DELAY), deep aquifer percolation fraction (RCHRG_DP), snow pack temperature lag factor (TIMP), the average monthly precipitation during the prediction period (PCPMM), temperature and precipitation parameters and surface runoff lag time coefficient (SURLAG) were the most sensitive parameters in the watershed. Conclusion The calibration and validation results for the base period (1992-2008) showed that the accuracy of the simulations was satisfactory for the discharge and sediment values. The obtained evaluation criteria r-factor, p-factor, and R2 for the calibration period were 1.01, 76% and 0.79 and for the validation period were 0.76, 72% and 0.57, respectively. Therefore, due to the noticeable effects of spring discharge data and the input parameters on the runoff simulation in the study area, it appears that it is essential to consider these factors for the runoff simulation using SWAT in similar mountainous watersheds with high topography.
Volume 42 - Issue 1
Soil Biology, Biochemistry and Biotechnology
Marzieh Mazraeh; Roya Zalaghi; Naiemeh Enayatizamir
Abstract
Introduction Growth-stimulating bacteria are now proposed as an alternative to chemical fertilizers in order to increase soil fertility in sustainable agriculture. Biofertilizers are also expressed as microbial inoculants that are capable of removing soil nutrients from an inaccessible state through ...
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Introduction Growth-stimulating bacteria are now proposed as an alternative to chemical fertilizers in order to increase soil fertility in sustainable agriculture. Biofertilizers are also expressed as microbial inoculants that are capable of removing soil nutrients from an inaccessible state through biological processes. Plant Growth Promoting Bacteria (PGPRs) refer to a broad group of susceptible bacteria, which grow alongside the plant as the host and stimulate plant growth. On the other hand, these microorganisms in the soil are able to stimulate and improve biological indicators, such as microbial carbon biomass, microbial respiration, and microbial yield, and may also affect different forms of carbon in the soil. Among the PGPRs, it is possible to refer to Enterobacter and Pseudomonas. Pseudomonas are bacteria present in all agro-soils and have different growth-promoting characteristics. Enterobacteriaceae family is a large group of bacteria that are naturally present in the water, soil, and materials that are corrupted and contaminated. To evaluate the biological changes of soil due to the activity of PGPRs, biochemical parameters (microbial respiration and microbial carbon biomass) are usually monitored in the plant's rhizosphere. The rhizobox is one of the tools used to study the changes in the rhizosphere, by limiting the roots in a certain volume of soil and facilitating the sampling of rhizosphere soil. The aim of this study was to investigate the effect of plant growth-promoting bacteria on some biological and chemical properties of the soil under Rhizobox conditions. Materials and Methods In order to study some of the chemical and biological properties of the soil cultivated with maize and wheat and inoculated with growth promoting rhizobacteria (PGPR), a completely randomized design, including two maize and wheat plants and three levels of inoculation, including non-inoculated, Pseudomonas sp. strain Rhizo_9 and Enterobacter cloacae strain Rhizo_33 in three replications in Rhizobox pots was done in greenhouse conditions. At the end of the period, the plants were harvested and the dry weight of roots and shoots was measured. Also, 3 soil samples were sampled from each rhizobox, as follows: rhizosphere 1 (soil clinging to the root), rhizosphere 2 (1 cm soil clinging to mesh), and non-rhizosphere (soil far from the mesh). Some soil characteristics, including basal respiration, substrate induced respiration, metabolic quotient, and soil carbon components (soil organic carbon, microbial carbon biomass, cold-water-soluble carbon, hot-water-soluble carbon, and permanganate oxidable carbon) were measured. Results and Discussion Results showed that the amount of each carbon component, as well as basal and substrate-induced respiration in treatments with bacteria, was higher than non-bacterial treatments and these biological properties in the soil cultivated with maize were higher than those under wheat cultivation. According to the results, the highest amounts of the basal respiration (0.31 mg CO2 g-1 day-1), the substrate-induced respiration (1.65 mg CO2 g-1 day-1), the permanganate oxidable carbon (213.1 mg kg-1), and the microbial carbon biomass (17.53 mg 100g-1) were related to rhizosphere 1 soil of maize inoculated with Pseudomonas. The highest amounts of the organic carbon (0.82%), the cold-water-soluble carbon (1727 mg kg -1), and the hot-water-soluble carbon (955 mg kg-1) were related to rhizosphere 1 soil in maize inoculated with Enterobacter. This could show the differences between two bacteria in affecting on different forms of carbon in the soil. Conclusion The results of this study showed that maize had a higher effect on carbon forms of soil that could be because of higher root biomass and probably higher root secretions of maize in comparison to wheat. Also, by increasing the distance from plant roots (from rhizosphere1 soil to bulk soil), different forms of carbon decreased that showed the impact of rhizosphere (plant roots and rhizospheric microorganisms) on physicochemical and biological characteristics.Inoculation of PGPR bacteria caused an increase in soil respiration and soil different carbon forms but the two bacteria were different in increasing various forms of soil carbon that seems to be related to different secretions or different effects of bacteria or plant-bacteria associate on soil carbon forms. Although inoculation of Pseudomonas resulted in a higher amount of microbial carbon biomass, inoculation of Enterobacter resulted in higher amounts of cold-water-soluble carbon, hot-water-soluble carbon, and soil organic carbon. Also, the application of two PGPR bacteria (Enterobacter was more effective) increased root and shoot dry weights of maize and wheat compared to non-bacterial treatments.
Volume 41 - Issue 2
Soil Physics, Erosion and Conservation
shamsollah ayoubi; zanyar feizi; Mohammad reza Mosaddeghi; Ali asghaar besaltpour
Abstract
Investigating the application of biochar, bentonite clay and polyvinyl acetate polymer on some mechanical properties of sand deposits IntroductionWind erosion seriously threatens bare soils and is recognized as a global environmental problem; however, little is known about this process in comparison ...
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Investigating the application of biochar, bentonite clay and polyvinyl acetate polymer on some mechanical properties of sand deposits IntroductionWind erosion seriously threatens bare soils and is recognized as a global environmental problem; however, little is known about this process in comparison to rainfall or tillage erosion. Due to the heavy costs of controlling wind erosion and the difficulty of detecting which control measure is the most effective, the correct selection of technical methods is indispensable for a suitable land management. Since the last decades, the methods of sand stabilization studied are diverse, but basically based on wind speed reduction by including chemical, mechanical and biological methods. One of the most important methods of stabilizing sandy soils is the use of mulches. In recent years, due to the disproportionate development of residential in peri-urban areas, humans use polymeric and oil mulches to stabilize sandy soils. Therefore, in this research, the effects of bentonite clay, polyvinyl acetate and palm biochar on reducing soil erosion by wind in peri-urban areas were investigated.Methods and Materials Three selected treatments were compared with a control plot without any treatment: palm biochar, polyvinyl acetate and bentonite clay. In order to prepare the palm biochar, palm remnants including the trunk, foliage and palm leaves were poured into the mill and turned into small pieces. The fragments were passed through a 2 mm sieve. The remnants transmitted from the sieve were poured into the trays of the discharger unit and placed inside a discharger at 350°C for 4 hours, and the biochemicals were prepared to the extent necessary for this research. Polyvinyl acetate treatment was provided by Isfahan Resin Co. and the bentonite clay by the Derin Kashan enterprise (both of them from Isfahan, Iran). To apply the treatments, each of them was mixed with a certain proportion of water per m2: i) 20 g l-1of palm biochar treatments; ii) 7 g l-1 of polyvinyl acetate treatment; and, iii) 20 g l-1 of bentonite clay.In order to apply the treatments, 36 galvanized trays with a same size (5×35×105 cm) were prepared and filled up from the air to the top edge with sand. After 1, 2, 4, 10 and 20 weeks some mechanical and physical properties were measured in laboratory. Results and Discussion A significant difference was observed among different treatments in terms of the impact on aggregates formations and stabilities at different moments. The application of bentonite clay treatment significantly increased the stability of formed aggregates compared to control treatment. The rest of treatments showed lower aggregability. The mean weigh diameter (MDW) for the control plot was 0.28 mm. The lowest MWD was obtained by the palm biochar treatment, which increased by 20.1, 14.9, 9, 2.5 and 1.6% after the first, second, fourth, tenth and twentieth weeks of application, respectively. Polyvinyl acetate treatment increased MDW by 65.1, 61.6, 58.8, 41.9 and 31.5% after the first, second, fourth, tenth and twentieth weeks, respectively. The highest MWD was obtained by bentonite clay treatment, which generated an increase by 77.8, 71, 65.1, 59.9 and 49.7% in the first, second, fourth, tenth and twentieth weeks, respectively). The images from thin sections of bentonite clay and polyvinyl acetate treatments showed that soil particles were joined to form larger aggregates in all of cases.No significant differences was observed for hydraulic conductivity at different times were observed. There was a significant difference among different treatments at different monitoring periods. The application of bentonite clay significantly reduced the fractal dimension. On the contrary, the lowest effect was registered for the palm biochar treatment. The effect of bentonite clay treatment on soils was higher than other selected treatments showing a reduction by 10.6, 9.7, 8.7 6.7 and 6.3% in the first, second, fourth, tenth and twentieth weeks, respectively. The impact of different treatments on shear resistance showed that the application of the selected treatments significantly increased the shear strength in all the cases. Among the selected treatments, the effect of bentonite clay treatment on shear resistance was higher than other treatments. The lowest and the highest shear resistance were registered for the palm biochar and bentointe clay, respectively. Palm biochar increased shear resistance by 9.3, 9.3, 8, 5.3 and 3.3% compared to the control plot in the first, second, fourth, tenth and twentieth weeks after its application. On the other, bentonite clay registered the highest improvement in shear resistance by 44.7, 44.7, 42.7, 37.3 and 31.3% in the first, second, fourth, tenth and twentieth weeks, respectively. Keywords: Mulches, Bentonite, Clay, Biochar, Palm, Mechanical properties
Volume 41 - Issue 4
Plant Nutrition, Soil Fertility and Fertilizers
Amir Rahimi; Behnam Doulati; Saied Heydarzadeh
Abstract
Introduction Nutritional deficiencies (e.g. Iron, Zinc, Manganese and Boron) account for almost two‐thirds of the childhood death worldwide. Most of those afflicted are dependent on staple crops for their sustenance. Declining soil fertility in many countries, duo to continuous cropping systems, has ...
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Introduction Nutritional deficiencies (e.g. Iron, Zinc, Manganese and Boron) account for almost two‐thirds of the childhood death worldwide. Most of those afflicted are dependent on staple crops for their sustenance. Declining soil fertility in many countries, duo to continuous cropping systems, has reduced soil production capacity affected by depletion of soil nutrient without proper replacement. Soil application of prepared humic substances is not economical, but the response to foliar sprays has the potential to be economical because the relatively small quantities are needed. Foliar application is one of the swift response methods for plants to add fertilizer, which leads to dispel of nutrients deficiency and providence in the use of chemical fertilizers. The solubility of nutrients decreases in soils with high acidity or undesirable chemical composition and can be possibility of ionic competition (Antagonism) or the accumulation of nutrient in soilcanlee resulthed. Therefore, adsorption of nutrients and root growth will be inappropriate. On the other hand, the application of humic substance with improving physical, chemical and biological conditions causes an increase in adsorption and soil fertility. Using humic substances is another benefit of the reduction of environmental pollution in order to achieve sustainable agriculture. A sugar beet is a plant whose root contains a high concentration of sucrose and which is grown commercially for sugar production. Sugar beet is one of the strategic crops and is widely cultivated in the West Azerbaijan region. So, the aim of this study was to investigate the application of humic substances and micronutrient on some quantitative and qualitative characteristics of sugar beet. Material and Methods This study was carried out as a randomized complete block design with six levels of humic substance (0, 200, 300, 400, 500, 600 kg ha-1) and foliar application of micronutrients including Fe, Zn, B, and Mn with 3 replications. Physicochemical properties of soil (calcium carbonate equilibrium, pH, OC, EC, micro and macro elements, soil texture) were determined by standard methods. There fore, quantitative and qualitative characteristics of sugar beet including total sugar content, pure sugar content, and molasses sugar content, Na, K and N content in root, alkalinity, sugar extraction coefficient, root yield and pure sugar and total sugar yield were determined in sugar beet samples. Results The results showed that the application of humic and micronutrient was significant in qualitative and quantitative characteristics of sugar beet. Maximum root yield (68.96 ton ha-1) was obtained in the Mn treatment. The highest of pure (16.30%), gross sugars (18.68%) and sugar extraction coefficient (87.25%) was observed in B and 500 kg ha-1 of humic asid treatment. Humic acid application increased nitrogen (27.58%) and root yield (29.08%) compared to control. Also, micronutrient and humic substance application reduced the molasses sugar content and increased potassium in the root of sugar beet. So that the highest (3.48%) and lowest (2.37%) amounts of molasses sugar were obtained in control and 500 kg ha-1 humic acid plus B treatment respectively. Boron is much required for cell division and development in the growth regions of the plant near the tips of shoots and roots. It also affects sugar transport and appears to be associated with some of the functions of calcium. Conclusion According to the results of this study, foliar application of humic substance and micronutrient improved qualitative and quantitative characteristics of sugar beet. The root and refined sugar yields are among the most important components in sugar beet production. Also, treatment of 600 kg ha-1 of humic acid and Mn spraying had the greatest effect on the root and gross sugars yield in sugar beet. Also, the amount of molasses sugar decreased with increasing sugar content and replacing potassium instead of harmful elements. Application of Mn and B may need to be considered for sugar beets. Foliar fertilization with Mn has the beneficial effect mainly on such features like White sugar yield, root, gross sugars yield, and the number of leaves per single sugar beet plants. It can be concluded that the contemporary use of humic substance and micronutrient is recommended in order to achieve adequate yield and preserve the environment.
Volume 42 - Issue 2
Precision Agriculture
Seyedeh Arefeh Hosseini; Hassan Masoudi; Seyed Majid Sajjadiyeh; Saman Abdanan Mehdizadeh
Abstract
Introduction Nitrogen is one of the essential elements for plants and is consumed more than other elements in plant nutrition. Nitrogen is an important component of the chlorophyll molecule and is present in the chlorophyll structure as a protein. Without nitrogen, plant growth decreases significantly. ...
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Introduction Nitrogen is one of the essential elements for plants and is consumed more than other elements in plant nutrition. Nitrogen is an important component of the chlorophyll molecule and is present in the chlorophyll structure as a protein. Without nitrogen, plant growth decreases significantly. This research was carried out to estimate the amount of nitrogen and chlorophyll of sugarcane leaves from color indices extracted from digital aerial images taken by a quad-copter at two 5 and 10 m altitudes in the fields of Debal Khozaie sugarcane agro-industry company, Khuzestan, Iran. The images used for this research are from three farms with different growth stages. Materials and Methods The imaging was carried out using a quad-copter, the Phantom 3 professional model, at two heights (5 and 10 meters) from the specified points in the fields. After taking the photos from all marked points by the quad-copter camera, four healthy cane branch - with 45 cm distance from each other - were picked at each point and placed in plastic bags. Then, samples were immediately transferred to the laboratory to measure the leaf chlorophyll value, moisture content and the amount of nitrogen. Using a hand-held chlorophyll meter (SPAD-502 model), the leaf chlorophyll index was measured and recorded at each point. After drying the samples, the nitrogen levels were measured using the manual Kjeldahl method. The designed image processing algorithm, to extract color indices from sugarcane fields' images, had these steps: image transfer, preprocessing, image smoothing, noise, and background removal, extracting and selecting of image attributes. After using the image processing algorithm, the color indices of the fields' images were obtained; then the relationship between color indices and nitrogen and chlorophyll content of sugarcane leaves were determined using multivariate regression. The preparation of the data was done in Excel 2013 software and the development of multiple regression equations in SPSS v.21 software. The student t-test was used to compare the performance of regression models in the prediction of nitrogen and chlorophyll content with real values. Results and Discussion Based on the results of the measurements, the dispersion of nitrogen was not uniform throughout and between the fields. The least nitrogen dispersion was in the first growth period and the greatest one in the second growth period. None of the fields had uniform dispersion in the chlorophyll content. The least dispersion was observed in the second growth period and the highest dispersion in the third growth period. Based on the Pearson correlation statistical analysis - from 48 features extracted by image processing including mean, variance, skewness, and peak value of each image color indices in RGB, HSV, HIS, and Lab color spaces - only 24 features were selected to determine the regressions equations. These indices had a correlation with the amount of nitrogen in sugarcane leaves. In the images of 5 meters height, the obtained regression equation for nitrogen estimation was significant at 1% probability level and had a 74.3% determination factor. The determination factor of the five regression equations presented for the images taken from 10 m height were 71, 74, 77, 79, and 82 percent. Also, all the regression equations were significant at 1% probability level, so these relationships are valid and can be used to estimate the amount of nitrogen in sugarcane from 10 m height. By increasing the number of color indices, the accuracy of the regression model in the estimation of nitrogen levels was increased. Accuracy of the 10 m regression model for estimating the amount of nitrogen in sugarcane was higher than the 5 m regression model. All four regression models presented for estimating the chlorophyll of leaf based on color indices of images taken from 5m height were significant at 1% probability level. The obtained determination coefficients for these models were 26, 45, 55, and 62%. By increasing the number of color indices, the accuracy of the regression model was increased for the estimation of chlorophyll content of the leaf. Also, the presented regression model for the estimation of leaf chlorophyll based on color indices obtained from 10 m height images was significant at 1% probability level. The determination factor for this model was 69%, which is more than the determination factor of the most accurate regression model presented for 5m height images. The regression model presented for estimating the sugarcane nitrogen content from leaf chlorophyll was significant at 1% probability level. The amount of determination factor for this model was 68%, which is very close to the amount reported by the Debal Khozaie sugarcane agro-industry company, Khuzestan, Iran. Conclusion Thecomparison of the results of regression equations with real values showed that nitrogen prediction with regression model for 5 m height images and two regression models for 10 m height images had no significant difference with each other. Also, the results of sugarcane nitrogen estimation using the leaves chlorophyll was not significantly different from the actual nitrogen content of leaves. On the other hand, chlorophyll prediction was performed by two regression models for 5 m height images and the regression model for 10 m height images were not significantly different from the actual amount of leaves chlorophyll. Therefore, the presented regression equations are valid and reliable and using these relationships can help know the state of nitrogen and chlorophyll in sugarcane fields.
Volume 40 - Issue 1
M. Karami; S. Ayoubi; H. Khademi
Volume 43 - Issue 1
Fatemeh Miri; Javad Zamani babgohari
Abstract
Introduction: Biochar which is used as a soil amendment, is defined as a stable-carbon-rich product, and can endure in soil for thousands of years. Biochar is produced from biomass such as wood, manure, leaves, and other agricultural waste via pyrolysis, by heating at temperatures 300-1000°C in a ...
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Introduction: Biochar which is used as a soil amendment, is defined as a stable-carbon-rich product, and can endure in soil for thousands of years. Biochar is produced from biomass such as wood, manure, leaves, and other agricultural waste via pyrolysis, by heating at temperatures 300-1000°C in a closed container with little or no available air. Biochar, because of its potential to improve the physical and chemical properties of soil, is known as an effective soil amendment. Different types of organic waste particularly the residual of plants can be used as feedstock to produce biochar, but it's important to assess the Biochar properties to apply it as a soil amendment.Materials and Methods: In this study, we investigated some physicochemical properties of biochar of pistachio ́s waste, produced in different pyrolysis temperatures. The pistachio harvesting waste was collect from pistachio orchards in Zarand city, which mainly consisted of the green husk, pistachio cluster, leaves and small amounts of nut and woody shell and thin wood waste. A series of biochar were produced from pistachio waste by slow pyrolysis at different temperatures (300, 450, 600 and 750◦C, for 2 h) to find out the best temperature for the preparation of biochar from this matter. After preparation of biochars, their physicochemical properties including pH, electrical conductivity (EC), bulk density, particle density, biochar yield (mass of the biochar to dry mass of feedstock), ash content, water holding capacity (WHC) and stable-OC, were measured.Results and Discussion: In general, optimal biochar is the one that its yield, water holding capacity and stable organic carbon (OC) are higher and its electrical conductivity is lower. The results showed that as temperature increased from 300 to 750◦C, biochar yield and bulk density of the biochar decreased. In contrast, with increasing the temperature, pH, EC, particle density, ash content and stability of OC were increased. The electrical conductivity (EC) in the feedstock material was about 5.8 dS/m and their conversion to biochar and the increasing of pyrolysis temperature, increased the salinity of this material. The highest of EC was observed at 750◦C which was more than 2.5 and 6 times than in at temperature 300◦C and in the feedstock, respectively. The biochars produced at all temperatures have a high pH which it may be considered as an amendment for the reclamation of acidic soils, however the high salinity of the biochars could be a negative factor for plant growth. Also, as the pyrolysis temperature increased, the amount of ash in the biochar increased. The highest of ash content was observed at the highest temperature (58.3%) which was about 460% more than in the feedstock. Stable organic carbon in biochars produced at temperatures of 300, 450, 600 and 750◦C was about 49, 206, 227 and 227% higher than that of raw pistachio residue, respectively; and the percentage of yield of biochar at 300◦C was more than 65% higher than that of 750◦C. Although the WHC of biochars in different temperatures had no clear trend; it was slightly lower at a temperature of 450◦C in compared to the other temperatures. Also, in a trend, the biochars prepared at the higher temperatures showed higher stable-OC but lower yield.Conclusion: The temperature of the pyrolysis process is a key factor in the yield, quality, and physicochemical properties of the pistachio’s waste biochar. In the context of carbon sequestration as an environmental aspect and more yield of biochar as an economic aspect in the production of biochar and application of this matter in the soil, our results recommend the preparation of biochar from pistachio ́s waste, at temperature 450◦C or 600◦C, or a temperature in between. In the previous studies it has also been shown, the biochars produced at temperatures of 450◦C or higher was most likely to improve soil drainage and make more water available to plants but it needs more energy in the production procedure, while ones produced at lower temperatures could induce soil water repellency.Temperature of pyrolysis process is a key factor on yield, quality, and physicochemical properties of the pistachio’s waste biochar. In context of carbon sequestration as an environmental aspect and more yield of biochar as an economic aspect in production of biochar and application of this matter in soil, our results recommend the preparation of biochar from pistachio ́s waste, at temperature 450◦C or 600◦C, or a temperature in between. In the previous studies it has also been shown, the Biochars produced at temperatures of 450◦C or higher was most likely to improve soil drainage and make more water available to plants but it needs more energy in production procedure, while ones produced at lower temperatures could may induce soil water repellency.
Volume 40 - Issue 2
Plant Nutrition, Soil Fertility and Fertilizers
Faranak Ghasemi; ُSaeid Hojati; Ahmad Landi; Roya Zalaghi
Abstract
Introduction Clay minerals are considered as the main source of ion exchange and storage of nutrients in the soil. Knowledge of change and transformation of minerals, in relation to plant nutrition, fixation and release of elements is important. Sepiolite and palygorskite are fibrous clay minerals widely ...
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Introduction Clay minerals are considered as the main source of ion exchange and storage of nutrients in the soil. Knowledge of change and transformation of minerals, in relation to plant nutrition, fixation and release of elements is important. Sepiolite and palygorskite are fibrous clay minerals widely distributed in arid and semi-arid soils. Both minerals are rich in Mg and therefore, their weathering can significantly affect the chemistry of Mg in soil. Biological weathering which is carried out by living organisms (i.e. plant roots, soil fungi and bacteria) plays an important role in providing nutrients to plants. Hence, the use of microorganisms such as mycorrhizal fungi in the rhizosphere of agricultural crops has become more widespread. In recent years several studies have been conducted in relation to the weathering of minerals in the rhizosphere soil. However, few studies in terms of mycorhizal symbiosis with plant roots were carried out on release of Mg from sepiolite and palygorskite. Therefore, a pot experiment with a factorial arrangement through a completely randomized design was conducted to identify how symbiosis of sorghum roots with Glomus mosae mycorhizae affects release of Mg from sepiolite and palygorskite. Materials and Methods Pots containing sterile quartz sand and sepiolite or palygorskite (25-53 µm) were prepared and fungal treatments including presence or absence of fungus Glomus mosae were applied to the pots and then sorghum seeds were sown. Johnson nutrient solutions containing magnesium and without magnesium were used to feed plants during 70 days of experiment. After harvesting, the chlorophyll content, plants height and stem diameter were measured by SPAD, tape measure and caliper, respectively. Afterwards, the roots and shoots were separated and plants biomass and the percentage of roots colonization determined. Then, plants were oven-dried, ground, and the magnesium contents of them after extraction with 1M hydrochloric acid were determined using Agilent 7000 ICP analyzer. The chemical composition of palygorskite, sepiolite, and quartz sand was determined using X-ray fluorescence (XRF) and their mineralogical composition was determined using X-ray diffraction (XRD) approach. Results and Discussion Analysis of variance for the main effect of treatments on plant height, stem diameter, shoot dry weight and root dry weight showed that the effect of different sources of magnesium on plant height, stem diameter and shoot dry weight was significant (P < 0.01). The highest and lowest height, stem diameter, root and shoot dry matter were found in treatments fed with complete Johnson solutions and the palygorskite, respectively. The results also illustrated that application of Glomus mosae symbiotic mycorhizae significantly increased plant height, stem diameter, and root and shoot dry matter compared with non-mycorhizal treatments. This could be attributed to the fact that Mycorrhizal fungi (Glomus mosae) absorb more water and nutrients through increased photosynthesis and plant growth, consequently leading to improved plant characteristics when compared with non-mycorhizal crops. The results also showed the highest percentage of root colonization in palygorskite treatments and the lowest one in control. In general, a symbiotic relationship is created to improve low nutrition of elements that the amount of them in the soilwith a little mobility. Therefore, anything that exacerbates this deficiency, leads to an increase in symbiosis between plants and fungi. On the other hand, When plant is faced with more nutrient deficiencies, the demand for a symbiothic fungusGlomus mosae increases. Besides, the greatest magnesium concentration and chlorophyll contents were found in control, sepiolite and palygorskite treatments, respectively. In all treatments, magnesium intake was sufficient to grow sorghum, but as the results show, the amount of magnesium in the control and that of sepiolite was much more than palygorskite. These results clearly show that sepiolite mineral is able to release more Mg than palygorskite. The results also showed that the presence of the fungus Glomus mosae has significantly affected the release of Mg from both minerals. Conclusion In both sepiolite and palygorskite treatments, magnesium and chlorophyll content increased in symbiosis with fungi. This shows the positive effect of Glomus mosae fungus on release of Mg from these two minerals, especially sepiolite. Although, both sepiolite and palygorskite were able to provide enough amounts of Mg for sorghum plants, however, it seems that in long-term Mg released from sepiolite can more easily meet the need of plants when compared with palygorskite.
Volume 47 - Issue 1
Post Harvesting Technology
Mozhgan Azhdar; Narges Shahgholian; Hassan Zaki Dizaji; mansour amin
Abstract
Introduction: These days, most of the disinfectants used in the food industry such as chlorinated compounds are dangerous and harmful. Common methods of removing all types of pollution have many disadvantages for human health and the environment. It is possible to help preserve the environment and human ...
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Introduction: These days, most of the disinfectants used in the food industry such as chlorinated compounds are dangerous and harmful. Common methods of removing all types of pollution have many disadvantages for human health and the environment. It is possible to help preserve the environment and human health by replacing these methods with new ones such as ultrasound technology. Ultrasonic waves are non-thermal technology that helps increase microbial safety and prolong the shelf life of heat-sensitive foods with nutritional value and functional characteristics. Ultrasonic waves are known as one of the most effective disinfection methods for all forms of microbial and fungal contamination. These waves reduce the resistance of microorganisms by physically damaging them. Therefore, this study deals with the effect of high-power ultrasound waves on the population of two type of pathogenic microorganisms in the washing effluent of tomatoes. The selected bacteria included one type of gram-positive bacteria (Staphylococcus. aureus) and one type of gram-negative bacteria (Escherichia coli) to compare the effect of ultrasound waves on the two different types of bacteria with different cell walls. Materials and Methods: In this research, irradiation of high-power ultrasound waves were applied to the water after washing the tomatoes. In this washing effluent, the impacts of ultrasonic power (100, 300, 500 W), radiation time (300, 750, 1200 s), and water temperature (0, 30, 60 °C) were examined on the survival of the S. aureus and Ecoli. The data analysis was done for each experimental runs, using the response surface methodology (RSM), to find the best model for estimating the difference in bacterial population (CFU) before and after irradiation. Results and Discussion The lack of fit was not significant in the analysis of variance and also the value of the explanation coefficient in the model for S. aureus and Ecoli were 0.9721% and 0.9206% respectively. This indicated the appropriate accuracy of the quadratic model in estimating the number of S. aureus and Ecoli remaining in the water after washing tomatoes (for the mentioned independent variables). Gram-negative bacteria (E coli), are composed of an inner thin peptidoglycan cell wall, surrounded by an outer lipopolysaccharide membrane. Gram-positive bacteria (S. aureus), lack an outer membrane but are made up of a multi-layered and very complex structure layers of peptidoglycan many times thicker than is found in the Gram-negatives. In general, the application of ultrasound waves causes to destruction of the mentioned bacteria. The main disinfection effect of ultrasonic waves on the population of S. aureus was power, while for Ecoli the main variable was temperature (based on the highest coefficient of quadratic equations/ 99% confidence level). Through physical, chemical and mechanical effects caused by acoustic cavitation, ultrasound is able to affect the bacterial suspension without producing a side product. The antimicrobial effect of ultrasound is achieved by a combination of chemical effects such as the production of active free radicals and thermal effects such as the production of local hot spots. The observations showed that increasing the temperature first increased and then decreased the effectiveness of ultrasound waves in the inactivation of bactetria. The negative effect of increasing temperature can be related to the decrease in the intensity of bubble explosion. Conclusion: According to the results of the experimental tests in the average time (750 s), with the simultaneous decrease in temperature (from 60 to 0 ºC) and increase in power (from 100 to 500 W), the destruction effect of ultrasound waves on S. aureus and Ecoli was increased. In the perturbation curves, the simultaneous effect of all three parameters (temperature, time and power), were investigated at the middle points (30 ºC, 750 s and 300 W). At these points, power changes were more effective in reducing S. aureus population, while temperature changes were more effective on the reduction of E coli. The population of S. aureus and E. coli decreased by increasing power of ultrasonic waves. Temperature and power had a synergistic effect, that is, the increase of both parameters led to the decrease of bacteria population. Finally, the tested variables were optimized by desirability in the RSM to minimize the population of microorganisms (S. aureus and E coli simultaneously), and parameters (in the range) obtained for the ultrasonic power, time, and temperature were 300 W, 1200 s, and 0 °C respectively.
Volume 44 - Issue 1
Parstoo Aslani; Masoud Davari; Mohammad Ali Mahmoodi; Farzad Hosseinpanahi; Naser Khaleghpanah
Abstract
Introduction Soil quality is one aspect of sustainable agroecosystem management. The application of zeolite minerals alone or in combination with other soil amendments (organic and inorganic fertilizers) can, directly or indirectly, affect soil quality indicators. Considering the unique characteristics ...
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Introduction Soil quality is one aspect of sustainable agroecosystem management. The application of zeolite minerals alone or in combination with other soil amendments (organic and inorganic fertilizers) can, directly or indirectly, affect soil quality indicators. Considering the unique characteristics of zeolites, such as the low-cost and abundance of its mines in Iran and the large area of wheat cultivation in Kurdistan province, the need to study the effect of zeolite application on soil properties and wheat yield becomes apparent. Although there is a lot of research on the impact of zeolite on improving soil properties and increasing the yield of various crops, few studies have been done on its residual effects. Therefore, in this study, we investigated the effect of zeolite and nitrogen (N) application on some basic soil properties, N efficiency, and wheat yield under field conditions after two years of zeolite application. Materials and MethodsBefore conducting the research, a composite soil sample from the soil surface (0 to 30 cm depth) was collected and analyzed to assess the farm's soil properties. The experiment was laid out in a split-plot based on a randomized complete block design with three replications at the University of Kurdistan research farm in Dehgolan. The main plots consisted of natural zeolite at four levels (0, 5, 10, and 15 ton. ha-1). Within each main plot, subplots were subjected to nitrogen applications at five levels (0, 50, 100, 150, and 200 kg. ha-1). Urea fertilizer was used to supply the required nitrogen. Zeolite was only utilized in 2018 and mixed into the surface layer of soil. The experiment was repeated in 2019 except for no addition of zeolite. The field was under potato cultivation in the first year of the experiment and followed by wheat crop in the second year. Wheat cultivation (Pishgam cultivar) was done in 2019 by grain seeders in plots with dimensions of 4.5 × 8.25 m. At the end of cultivation season, harvest was done from each plot, and some plant traits (grain protein, thousand-grain weight, spike number, grain number in spike, an economic yield of the plant, biological yield of plant, harvest index, and chlorophyll concentration) were measured. In order to investigate the effect of zeolite on basic soil properties, soil samples were collected from plots in the second year after harvest, and a number of physical and chemical properties of the soil were measured (dry bulk density (ρb), particle density (ρp), total porosity (f), saturated hydraulic conductivity (Ks), electrical conductivity (EC), soil reaction (pH), cation exchange capacity (CEC), and total soil nitrogen (TN)). Statistical analysis of data was performed using SAS 8.02 software.Results and DiscussionThe results from the second year indicated that the applications of zeolite or nitrogen alone or in combination with each other decreased dry bulk density and particle density of soil, but increased total porosity, saturated hydraulic conductivity, electrical conductivity, soil reaction, and cation exchange capacity. The porous structure of zeolite helps improve soil structure and increase porosity, thereby reducing the bulk density of the soil. Also, zeolites can affect the soil hydraulic conductivity due to channels in their structure. Zeolite is not acidic but marginally alkaline, and its use with fertilizers can help buffer soil pH levels. The very open structure of the zeolite and the similar pore network create a high specific surface area for the storage and exchange of nutrients. Therefore, different salts can be absorbed or desorbed from the zeolite structure. Desorption of salts from the zeolite can increase EC in the soil. The high cation exchange capacity and porosity of zeolite increase soil CEC, which increases the soil's ability to retain nutrients such as ammonium. The results also revealed that the grain protein, thousand-grain weight, spike number, grain number in spike, an economic yield of the plant, biological yield of plant and harvest index, with mean increasing about 37%, 6%, 30%, 15%, 43%, 26% and 7%, respectively, compared with the control, were significantly affected by zeolite and nitrogen applications, and also zeolite and nitrogen interaction. However, the chlorophyll concentration was not meaningfully influenced by them. Increased grain yield can be attributed to reduced nitrogen leaching and increased soil water holding capacity in the presence of zeolite, which improves nitrogen status and the availability of water for growth. Drought stress significantly affects grain yield, harvest index, thousand-grain weight, spike number, grain number in spike, and plant height. The use of zeolite can maintain soil moisture for a longer period and mitigate the adverse effects of drought stress on the crops.ConclusionThe improved agronomic traits and enhanced grain yield potentials induced by zeolite amendment were related to decreased drought stress in wheat crops and the increase in soil quality indicators and N uptake. The zeolite application probably enhanced NH4+–N retention in the topsoil and prevented NO3-–N from leaching into the subsoil. In general, the results showed that the combined application of zeolite and N can be a beneficial approach for increasing nitrogen fertilizer efficiency and improving the sustainability of agricultural systems.
Volume 46 - Issue 2
Plant Nutrition, Soil Fertility and Fertilizers
Fatemeh Meskini-Vishkaee; Ali Reza JAfarnejadi
Abstract
Introduction In Iran, salinity is a pervasive and limiting Factor of agricultural sustainable production. Plants in saline conditions are exposed to limited absorption of nutrients, water and toxicity of some elements and subsequently, their yield will be affected by salinity. Moreover, dust storms in ...
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Introduction In Iran, salinity is a pervasive and limiting Factor of agricultural sustainable production. Plants in saline conditions are exposed to limited absorption of nutrients, water and toxicity of some elements and subsequently, their yield will be affected by salinity. Moreover, dust storms in arid and semi-arid climates are one of the most important environmental and pollution problems, as they directly and indirectly reduced the quality and quantity of agricultural products. Dust occurrence frequency in the country, especially in the western and southwestern regions increased in the last decades. Hence, increased dust occurrence frequency and intensity during the growth period of agricultural crops is one of the most substantial risks in agricultural sustainable production in Khuzestan province. Thus, the aim of the study was to investigate the effects of dust occurrence and farm management practices applied to reduce the effects of this stress on wheat yield indices as a strategic agricultural product in Khuzestan province. Materials and Methods This study was carried out in Khuzestan province in a calcareous and saline soil with clay loam texture under wheat cultivation (Barat cultivar) as a split plat experiment in a randomized complete blocks design with three replications. Two agricultural farm managements included 1) the custom of the farmer (traditional farming) and 2) nutrition management (soil test, soil balanced and complementary nutrition) based on plant phenological growth stages. In each farm management operation, four leaf washing treatments including 1) without leaf washing, 2) leaf washing after the occurrence of dust phenomenon in the tillering stage, 3) leaf washing after the occurrence of dust phenomenon in the booting stage and 4) leaf washing after the occurrence of dust phenomenon in both the tillering and booting stages, in plots with an area of 20 m2 were applied in three replicates. At the end of the growth season, wheat yield indices involved thousand kernel weight, number of grains per spike, biomass weight, grain yield and the number of tillers per square meter in different treatments were determined. SAS v.9.1 statistical software and Duncan's multiple range test were used to compare the means of the studied treatments.Results and Discussion The results showed that the highest wheat grain yield was observed in the treatment of balanced nutrition management and leaf washing after dust occurrence at two wheat growth stages (5180 kg ha-1), while the least wheat grain yield was in the traditional management and no leaf washing treatment (2830 kg ha-1). The interactions of farm management practices and different leaf washing treatments on biomass, grain yield, harvest index, thousand kernel weight and number of tillers per square meter were significant (p< 0.01). In the traditional management of the farmer, using the plant leaves washing at only one wheat growth stage after the occurrence of dust caused about 30% increase in wheat grain yield on average (24 and 35% increase in grain yield as a result of leaf washing after dust, respectively, in the tillering and booting stages). While in the traditional management and leaf washing at both two stages of wheat growth, it increased the wheat grain yield by 43%. In addition, the results showed that by using balanced nutrition management without leaf washing, wheat grain yield and harvest index increased by 10 and 9%, respectively. Application of balanced nutrition and leaf washing after the dust occurrence at both two wheat growth stages (tillering and booting) caused 32, 59, 21 and 11% increase in biomass, grain yield, harvest index and thousand kernel weight of wheat.Conclusion Based on the results of this research, it was found that the use of different management operations in the farms, such as balanced nutrition of the crop based on the plant growth phenological stages and the leaves washing after the occurrence of dust, can significantly reduce the damage of wheat yield caused by the occurrence of dust. However, it should be noted that despite the positive and significant effect of washing the plant leaf surface after the occurrence of dust phenomenon on reducing wheat yield damage, the time of leaves washing application is very important. Because if immediately after washing the leaf surface of the plant, the dust phenomenon occurs again, the wetness of the plant leaf surface causes more dust particles to deposit on it and the damage caused by dust on wheat yield indices increases.All right reserved.
Volume 44 - Issue 2
Farzaneh Bandehelahi; Isa Esfandiarpour-Boroujeni; Alireza Karimi; Mohammad Hady Farpoor; Zohreh Mosleh; Morteza Fattahi
Abstract
Introduction Landscape represents a large portion of land/terrain that is either formed by a repetition of similar or dissimilar relief/molding types or an association of dissimilar relief/molding types (e.g., valley, piedmont, mountain, etc.). It is usually affected by a set of natural (e.g., climate, ...
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Introduction Landscape represents a large portion of land/terrain that is either formed by a repetition of similar or dissimilar relief/molding types or an association of dissimilar relief/molding types (e.g., valley, piedmont, mountain, etc.). It is usually affected by a set of natural (e.g., climate, organisms, parent material, topography, time, erosion, sedimentation, etc.) and/or artificial (e.g., artifacts) factors. Soil is one of the most important components of landscape that is affected by various factors such as water and wind. Aeolian or alluvial sediments (from seasonal rivers) in arid areas cause the formation of different landforms and change the landscapes in these areas. Therefore, the study of geoforms in arid regions can lead to a better understanding of geomorphological processes and soil change in these areas. There are various methods, including soil micromorphology and clay mineralogy, to understand the alteration of landscapes and the soils change on them. The aim of this study was to investigate the physical and chemical properties, clay mineralogy and micromorphology of soils in various geomorphic units of Davaran Region, Rafsanjan.Materials and Methods Seven dominant geomorphic units (geoforms) of the region, including pediment, margin of fan and cultivated clay flat, alluvial fan, desert pavement, margin of pediment and sand sheet, active drainage, margin of fan and uncultivated clay flat were selected using Google Earth images and field studies. Nineteen pedons were excavated and described in the geomorphic units. After selecting a representative pedon in each of the geoforms, their genetic horizons were sampled. Besides, in order to conduct soil micromorphology studies, undisterbed and oriented samples were collected from selected horizons. After transferring the samples to the laboratory, their physical and chemical properties were measured using standard methods. In addition, clay mineralogy studies were performed by X-ray diffraction method and micromorphological studies were done using a petrographic microscope. Finally, soil classification was performed based on both Soil Taxonomy (2014) and WRB (2015) systems.Results and Discussion Results showed that gypsification and calcification are the dominant soil forming processes in the studied region, which have led to the formation of Gypsic and Calcic horizons. This has placed the soils in the Gypsids and Calcids suborders based on the Soil Taxonomy system and the Gypsisols and Calcisols reference soil groups according to WRB system. The representative pedon in the margin of fan and cultivated clay flat (pedon 2) geoform lacks a salic horizon based on the Soil Taxonomy; while it is in the Solonchak reference soil group of the WRB. Also, the presence of argillic horizon in the representative pedon of the margin of fan and uncultivated clay flat geoform (pedon 7) indicates presence of a more humid paleoclimate in the history of the region. The results of clay mineralogy showed that the predominant minerals in the region include chlorite, illite, kaolinite, and smectite. The illite, chlorite, and kaolinite are inherited from papent materials of the soils, and the smectite has a transformation origin (from palygorskite and illite). Addition of this mineral by aeolian or alluvial sediments could not also be neglected. The micromorphological results indicated that the soil pores were mainly chamber. The presence of carbonates and gypsum in the studied soils has caused that the b-fabric in the most horizons to be Calcitic Gypsic Crystallitic. Gypsum was observed in the form of vermicular, lenticular, interlocked gypsum plates and subhedral shapes. Other pedofeatures in the studied soils include calcite nodule and limestone.Conclusion The simultaneous presence of aeolian and alluvial sediments in the different geoforms of Davaran region has caused the formation of stratified soils. Existence of dry climate and lack of significant vegetation in the region from one hand, and the addition of different sedimentary layers at different times (which causes soil rejuvination) on the other hand, has caused that the soils of the region, in general, not to be highly developed. As a result, few differences were observed among soils in different geoforms. Comparing the results of two soil classification systems for the studied soils showed that in general there is a relatively good correlation between them. Totally, the role of climate and parent material in alteration of the studied soils is evident; so that the physical and chemical properties, clay mineralogy and micromorphology of soils in different geoforms have been affected.
Volume 43 - Issue 2
Nahid Aghili nategh; adieh anvar; mohammad jafar dalvand
Abstract
Introduction Sour cherry fruit (Prunus cerasus) is one of the most desirable fruit by the consumer due to its precocity and great quality. Pesticides are considered a basic ingredient of modern agricultural. Pesticides have been widely applied to protect agricultural products against detrimental pests, ...
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Introduction Sour cherry fruit (Prunus cerasus) is one of the most desirable fruit by the consumer due to its precocity and great quality. Pesticides are considered a basic ingredient of modern agricultural. Pesticides have been widely applied to protect agricultural products against detrimental pests, to ameliorate their quality, and increase product efficiency .The evaluation of pesticide residues in fruits has become too much required provisions for consumers, producers and authorities for fruit quality control. Nowadays, monitoring programmes for pesticides in food are carried out worldwide to guarantee consumer health, better management of agricultural resources, and to prohibit economic losses Acetamiprid is the most important pesticides of sour cherry. A possible tactic for defining the pesticide residues, sensing the aromatic volatiles released by fruit using e-nose. The e-noses (Electronic nose) is one of the best non-destructive methods which have shown to be well superseded for conventional methods in food odor detection Materials and Methods For detection the acetamiprid residue in sour cherry, the e-nose machine was designed and fabricated. The e-nose mainly composed of: data acquisition card (USB self-designed), sensor array, three two-way valves normally closed, vacuum pump, air filter (active carbon), GUI (LabVIEW 2014), power supply, laptop and sample chamber. The main stages of electronic nose work consist of three phases: 1- baseline 2- injection of sample odor into the sensor chamber 3- clearing the sensor array. The fractional method was employed in this research for baseline correction. Acetamipridpesticide Sprayed at 1 Liter per 1000 liters of water on cherry trees before pre-bloom in growth stage. This is a critical time for management of pests. Organic and inorganic healthy samples were collected from multiple trees sprayed and non-sprayed cherry trees and divided into four ripeness grades (RG1 = totally ripe, RG2 = close to ripeness, RG3 = intermediate to ripeness and RG4= unripe), according to the criteria used by expert growers (based on physical size and appearance as well as estimated maturity stages) during June2019. One uncontrolled (PCA) and one controlled (LDA) pattern recognition models were used to classify fruit samples. Results and Discussionorganic and inorganic sour cherries have different response patterns. This indicates that their aromatic compounds are different. Generally, in organic sour cherry MQ3sensor and in inorganic sweet cherry TGS2602 sensor had the highest response and role in detecting organic and inorganic sour cherries. PCA analysis described 89% to 96% of the variance in the diagnosis of organic and inorganic sour cherries. The value of variance in the first and second principal components changed from 63% to 91% and 17% to 26%, respectively. Organic and inorganic sour cherry in RG1, RG2, RG3 and RG4 significantly discriminated. To check the association of each sensor in the acetamipride diagnosis, loading plot, were used. In all of RGs TGS2620, TGS2610, MQ9 and TGS2611 have lowest response and sensors MQ3, TGS813, TGS2602 and TGS826 showed the highest contribution in detection acetamipride residue in sour cherry. For detection of ripeness grades of inorganic sour cherry the amount of variance in the first and second principal components was 81% and 10%, respectively. RG1 and RG2 and RG3 and RG4 overlapped. For organic sour cherry PC1 and PC2 described 63% and 26%, respectively, of the variance between samples. RG2 and RG3 overlapped. Also TGS2610, TGS2611 and TGS2620 have lowest response than to other sensors in detection RGs in organic and inorganic sour cherryLDA could specify acetamipride in sour cherry very well. The accuracy of LDA analysis for residual detection of acetamipride at 4 degrees of maturity was 83.3-100%. LDA could specify RGs of inorganic sour cherry well, but RG2 and RG3 and RG3 and RG4 have little overlap. The accuracy of the analysis was 95.83%. For organic sour cherry LDA could to distinguish RGs well, but RG3 and RG4 have little overlap. The accuracy of the analysis was 97.2% Conclusion Each two methods can be detected acetamipride, but LDA with correct classification percentage83.3-100%. are the best methods. According to the study, it can be expressed that the e-nose is a suitable instrument for detecting acetamipride residue of sour cherry and can be used with less time and cost to determine the appropriate harvest time.
Volume 43 - Issue 3
Ghasem Ghorbani Nasrabadi; Esmaeil Dordipour; mojtaba Barani; Elham Malekzadeh; Abdolreza Gharanjiki
Abstract
Introduction Salinity is one of the most important environmental stresses limiting agricultural production in arid and semi-arid regions, which occupies a relatively large area of arable land. Nutrient availability is decreased in saline conditions in soil solution and plant nutrient balance is changed. ...
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Introduction Salinity is one of the most important environmental stresses limiting agricultural production in arid and semi-arid regions, which occupies a relatively large area of arable land. Nutrient availability is decreased in saline conditions in soil solution and plant nutrient balance is changed. Nitrogen fertilizer management as an essential nutrient for plant growth is very important under salinity stress. Also, salicylic acid is a plant growth regulator involved in defense mechanisms of plants against biotic and abiotic stresses. Therefore, the aim of this study was to investigate the effect of salinity on the concentration of nutrients in wheat in response to salicylic acid consumption at different levels of nitrogen.Materials and Methods In order to investigate the effects of salicylic acid and nitrogen fertilizer application rates at different salinity levels on nutrient concentration of wheat cv. Morvarid, an experiment was conducted as a split plot factorial based on a randomized complete block design with four replications in the fields of Mazraeh-E-Nemooneh located in Anbarolum, Aq Qala city, Golestan province. The main factor included three soil salinity levels (3-4 below wheat tolerance threshold (control), 9-11 and 13-15 dS.m-1) and sub factors included two levels of salicylic acid (0 and 1.5 mM) and three levels of N fertilizer (from urea source, 46% N) were 1) N based on soil test recommendation, 2) 30% N more than soil test recommendation and 3) 30% N less than soil test recommendation, respectively. Salicylic acid was foliar applied twice for about 2 weeks in the tillering stage and 10 days after the second stage spraying, content in them was determined. Nitrogen treatments were applied in three stages - one third before planting with ammonium sulfate (21% N) and remains top-dressed with urea (46% N) at tillering and stem elongation stages. At the emergence stage of the cluster or the beginning of flowering of wheat, the amount of nitrogen in the flag leaf was measured. The concentrations of nitrogen, potassium and sodium in grain and straw were also measured by standard methods.Results and Discussion The results showed that by increasing salinity, the flag leaf N concentration, N and K concentration of wheat staw and seed decreased. However, Na concentration of straw and seeds increased. With increasing N and salicylic acid consumption, the concentration of N flag leaf, the seed and straw N and K concentrations increased, but the concentration of Na in seed and straw decreased.The interaction of salinity, salicylic acid and nitrogen on seed N and K concentrations and also on flag leaf N concentration was significant but there was no significant effect on other measured elements. Comparison of the mean of simple effects of salinity on the evaluated elements indicates a significant reduction of all studied elements due to salinity treatment. Also, comparison of the mean of simple effects of nitrogen fertilizer showed that all elements were affected by the treatment. The results of mean comparison showed a positive and significant effect of salicylic acid on the leaf N concentration of the flag leaf, so that the N concentration in the flag leaf in a 1.5 mM salicylic acid treatment was significantly increased compared to the non-use treatment.Conclusion according to the results, more nitrogen consumption at moderate salinity can have a positive effect on plant nutrition, and vice versa, at high salinity levels, it is better to reduce nitrogen consumption. The interactions of salicylic acid and nitrogen showed that in general nitrogen treatments with salicylic acid increased the N concentration of seed and straw. Nitrogen fertilization at higher and medium salinity levels increased the concentration of N and K in straw and seeds; However, at high salinity, less nitrogen fertilization improved the concentration of N and K. Also, nitrogen application with salicylic acid improved these traits under saline conditions. Therefore, the application of salicylic acid and nitrogen fertilizer management to some extent reduced the adverse effects of salinity up to moderate salinity levels and improved plant nutrition by increasing plant tolerance to salinity.Therefore, the application of salicylic acid and nitrogen fertilizer management to some extent reduced the adverse effects of salinity up to moderate salinity levels and improved plant nutrition by increasing plant tolerance to salinity.Key words: Salicylic acid, salinity stress, wheat, Nitrogen fertilizer management
Volume 45 - Issue 4
Plant Nutrition, Soil Fertility and Fertilizers
edris shabani
Abstract
Introduction The decrease in yield and quality levels of button mushrooms during the cultivation period is one of the important challenges of the mushroom production industry, due to the reduction of substrate nutrients and the accumulation of undesirable compounds. One of the solutions to prevent the ...
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Introduction The decrease in yield and quality levels of button mushrooms during the cultivation period is one of the important challenges of the mushroom production industry, due to the reduction of substrate nutrients and the accumulation of undesirable compounds. One of the solutions to prevent the decrease in yield and qualitative characteristics of edible mushrooms during different flushes is to enrich compost with nutrient supplements.Materials and Methods In order to investigate the effect of supplementary nutrition at different times on the yield indicators of button mushroom, a factorial experiment based on completely randomized design was conducted. Experimental treatments included four concentrations (C) of supplementary nutrition (0 (C1), 20 (C2), 40 (C3) and 60 (C4) g/L) (combination of two phases, the liquid phase includes micro and macro elements and amino acids, and the solid phase includes sucrose and dextrin) and two application times (one day after harvesting the first flush (T1) and the beginning of the second flush and the formation of pin (T2).Results and Discussion The findings of this research indicated the highest number of button mushroom was observed in C3T2 treatment by 215.89, which demonstrated a 20.35% increase compared to C1T2 treatment. The lowest single mushroom weight was measured in the first time of foliar spraying in C1T1 treatment and the highest single mushroom weight was obtained in the second time of foliar spraying in C3T2 and C2T2 treatments, respectively. The maximum length of the mushroom base was obtained in C2T2 treatment by 1.36 cm. Along with the increase in the concentration of nutritional solutions; the diameter of the cap showed a significant increase at T1 time, while at T2 time, this value showed a decreasing trend after the treatment of 20 g/L of nutrient solution. In addition, no significant difference was observed between the cap diameter of mushrooms treated with 20 and 40 g/L in treatments of C2T2 and C3T2, and the maximum cap diameter of mushrooms in these treatments was 3.73 and 3.67 cm, respectively. Enrichment of button mushroom compost by nutritional supplements can prevent severe yield reduction during different flushes.The number of mushrooms produced in two different times was not significant. It showed that the effect of using time of supplemental nutrition was more effective on the rapid growth of the formed pins than growth of new pins. The formation of pins and the number of mushrooms were under the influence of the amount of inoculation and used spawn in the compost. The positive results obtained from the foliar application of the nutrients showed that its compounds, including sucrose and dextrose and highly consumed elements such as nitrogen, phosphorus, potassium and amino acids, have played an important role on the number, single weight of mushrooms and the cap diameter of mushroom. The use of nutrient solution in C3T2 treatment compared to C1T2 increased nitrogen percentage by 66.43%, protein by 66.22%, tissue firmness by 71.44% and biological efficiency of substrate by 66.32%, respectively. Pervious study showed that, the effect of different concentrations of three amino acids asparagine, glutamine and glycine on some quality indicators and performance components of white button mushroom was investigated and the results indicated that asparagine 150 ppm improved the yield and increased the protein content. High NPK content in mushroom substrates significantly shortens the rate of mycelium propagation and increases oyster mushroom growth. One of the basic criteria for a good mushroom substrate is the carbohydrate and nitrogen content to support mushroom growth.Also, using a concentration of 40 g/L of nutrient solution at the time of emergence of the second pin, in comparison with C1T2 treatment, increased the yield of the second flush by 64.15%, the yield of the third flush by 71.17%, the yield of all flushes by 26.79% and the total yield of composted by 26.76%, respectively. Carbon, with its structural role and presence in most organic compounds and providing energy for metabolic reactions, plays a significant role in the growth of button mushrooms. On the other hand, button mushrooms are able to use amino acids as a source of nitrogen. Therefore, it seems that the use of the above compounds in the nutrient solution used in this research has been able to produce favorable results both quantitatively and qualitatively in the studied button mushrooms. On the other hand, it seems that the presence of widely used elements such as phosphorus and potassium in the nutrients used in this research and the positive role of these elements in the production of nucleic acid, adenosine triphosphate, membrane phospholipids and enzyme reactions has been able to play a key role in increasing the quantitative and qualitative properties of button mushrooms.Conclusion The use of 40 g/L concentration of nutritional supplement at the time of the appearance of the second flush by affecting the percentage of dry matter, protein and tissue firmness increased the quality level of button mushrooms and enhanced quantitative level by improving yield indicators such as the number of mushrooms, single weight of mushroom, total yield of flushes and percentage of total yield of compost.
Volume 44 - Issue 4
Abdollah Hayati; Afshin Marzban; Majid Rahnama
Abstract
Introduction Date fruit production has an important position in either Iran or the world. Life and economy of many of people who live in the West Asia and North Africa (WANA) depend on this agricultural product. Date palm crown access, as one of important operations of date fruit production, is performed ...
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Introduction Date fruit production has an important position in either Iran or the world. Life and economy of many of people who live in the West Asia and North Africa (WANA) depend on this agricultural product. Date palm crown access, as one of important operations of date fruit production, is performed in a traditional manner with a tool talked “Parvand” yet. It results in various ergonomic and safety problems, such as fall from height, sunstroke, and musculoskeletal disorders (MSDs). Meanwhile, mechanization could not adequately adopted by date palm growers. Possibly, ergonomic interventions in forms of simple tools mitigate ergonomic and safety problems in date palm crown access operation.Materials and Methods In this study, some ergonomic interventions were investigated to improve the present status of ergonomic and safety status of this operation with employing nine workers from Ramshir city, Khuzestan province, Iran. Evaluated date palm climbing tools were as follows: Parvand (traditional tool), Parvand+rubber shoes (intervened tool), harness (intervened tool), and harness+rubber shoes (intervened tool). Parvand consisted of a backrest and a towing wire. In two last mentioned intervened tools, harness was replaced with backrest in Parvand. Indeed, harness was the brief name of composition of harness and towing wire. Comparisons were done based on some ergonomic, safety, bio-mechanical, and technical indices. Ergonomic evaluations included physical and cognitive ones. Body discomfort (BD), heart rate (HR), worker energy expenditure (EE), working oral temperature (OT), and physiological strain index (PSI) were the physical indices. Perception-based heat Strain Index (PeSI) and acceptance of climbing tools in view of workers were the cognitive Indices. Acceptance comprised workers’ perception about safety, work speed, ease of use, technical properties, and preference of the tools. Safety evaluation was conducted using failure mode and effects analysis (FMEA) which resulted in a risk priority number (RPN) for each climbing tools. Bio-mechanical evaluations were performed using 3DSSPP software (to find the compression and shear forces on L5/S1 disc) and the investigation of mechanical stresses of Parvand and harness (to achieve the factor of safety (FoS) of tools). Technical index was the total time cycle (TTC) to perform date palm crown access (install climbing tool, ascending, and descending). Statistical analysis was conducted using IBM SPSS 24. During evaluation, workers’ qualitative feedbacks around intervened tools were recorded.Results and Discussion Mean age, height, mass and body mass index of workers were 33.1 years, 1.71 m, 74.0 kg, and 25.3 kg/m2, respectively. According to the statistical analyses, there was no any significant difference among climbing tools regarding BD, HR, EE, OT, PSI, PeSI, RPN, and TTC. Bio-mechanical evaluations showed that all four climbing tool caused a low risk compression force on L5/S1 (<3400), whereas interventions including harness were significantly higher than those including Parvand. Traditional and Parvand+rubber shoes with shear forces of 1120.9 and 1119.6 N, respectively, on L5/S1 disk resulted in high injury risk (>500 N) and were significantly higher than other two methods in which harness was used (p<0.001). FoS was achieved for Parvand and harness 1.21 and 3.53, respectively. Therefore, only harness could cover the minimum FoS required to work in height (2.4) according Ministry of Cooperative, Labor and Social Welfare’s regulations. During cognitive evaluations, harness+rubber shoes gained the highest safety level (score of 17) as well as the highest preference level (score of 14), whilst, Parvand+rubber shoes had the highest cognitive-based acceptance score (score of 58). Workers’ qualitative feedbacks, in order of frequency, were as follow: harness ropes should be wider (33%); towing wire-harness joint should be upper (from pelvis toward waist) (22%); harness ropes should be softer (especially around the thighs) (22%); harness should be integrated (i.e. without rope, like a short) from pelvis to thighs (11%); rope buckle should be used so that harness is more easily-and fast worn (11%).Conclusion Safety and work speed can be two main factors in the preference of a date palm crown access tool. Overall, intervened tools had a better state concerning safety, whereas, the qualifications were almost equal considering ergonomics. Notwithstanding it, the intervened tools had the lacks around work speed and technical properties which should be amended. Besides the attempts for development of date palm mechanization, further studies may be conducted on intervened date palm climbing tools, especially harness+rubber shoes method, based on workers’ qualitative feedbacks to gain a more appropriated level.
Volume 43 - Issue 4
Majed Ghosairy Sabry; Kamal Ganjalipour; Kamal Nabiollahi
Abstract
Introduction: CT scan was first invented by Hounsfield in the twentieth century in 1972. But it was soon used in engineering, agriculture, biology, physics, chemistry, etc. Recently, with advances in computed tomography at the global level, the use of different generations of X-rays on a micrometer scale ...
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Introduction: CT scan was first invented by Hounsfield in the twentieth century in 1972. But it was soon used in engineering, agriculture, biology, physics, chemistry, etc. Recently, with advances in computed tomography at the global level, the use of different generations of X-rays on a micrometer scale to study some of the different phenomena in soil science has begun. Due to the lack of geotechnical and soil mechanics studies in many engineering projects, CT scan image processing method can be used as a suitable method for extracting soil particle size and other soil characteristics. The main purpose of this study: a) The use of CBCT-scan in soil science for the first time in Iran. B) Comparing the ability of CBCT-scan in terms of quality of results with conventional methods. C) Identify the best filter and binary method (threshold). Another goal of this research is to acquaint more researchers with the application of computed tomography (CT-scan) technology in soil science studies.Material and Methods: The sampling area for this study was located in Diwandareh-Saqez axis in Kurdistan province, where six disturbed and undisturbed soil samples were collected in a sandy area (12 samples in total). In disturbed samples, particle size distribution was measured by ASTM D421 method, and the porosity of the samples was measured directly using the fuzzy equations in soil mechanics. In a radiology laboratory, three-dimensional images of intact soil samples were taken using a Planmeca Promax 3D CBCT CT scanner. In this study, ImageJ software was used to process CBCT-scan images. With this software, the percentage of phases, number of particles and particle size can be calculated. One of the most important steps in image processing is generating binary images. A total of 17 global thresholding methods have been proposed for generating binary images in ImageJ software. In this study, 15 standard methods for generating binary images were examined and the best method was selected. The total pore volume and soil particle size distribution of each sample calculated by quantifying X-ray images were compared with the total pore volume and soil particle size distribution obtained in the soil science laboratory and performance of the CT scan method evaluated by statistical parameters including The results of the accuracy evaluation for the correlation coefficient, mean absolute value of deviations, mean square error, root mean square error, and mean absolute error percentage.Results and discussion: The most significant point in image processing is the image thresholding method. In this study, due to the nature of CBCT-scan images, global thresholding was preferred. From the results of image processing, it can be understood that the results of binary images with Otsu and Intermodes methods are in complete agreement with the laboratory sample. The average of total porosity of the processing image slides is 44.03%, which is approximately consistent with the calculated 45/6% for the laboratory sample. Also, the average of ineffective porosity of the samples is about 6.53%. Therefore, it can be said that the effective porosity of the samples is about 37.5%. The results of the accuracy evaluation for the correlation coefficient, mean absolute value of deviations, mean square error, root mean square error, and mean absolute error percentage were 0.98, 1.082, 1.229, 1.108 and 2.334 respectively, indicating that the use of CBCT-scan images and image processing technique can identify and evaluate the geometric properties of granular soils with acceptable accuracy. The advantages of the computed tomography method of the soil are: (1) Obtaining information from the three-dimensional structure of the soil with appropriate accuracy in a short time, (2) Non-destructiveness of this method, and (3) Accurate separation into soil phases in different energy radiations.Conclusion: Using the processes defined by the authors for image processing, this technique is well able to determine some engineering features such as particle size distribution, total porosity, effective porosity and ineffective porosity. Also, the best thresholding method for binary images and processing in ImageJ is the Ostu and Intermodes method. The accuracy of the device used in this research is 0.2 mm, in other words, spaces or grains smaller than this value cannot be identified; For this reason, in the present study, the term coarse-textured soils, which means gravel to coarse-grained sand, has been emphasized. The results of evaluating the statistical parameters testify to the accuracy and ability of this method.
Volume 35 - Issue 1
Z. Mehraki; A. Landi; J. Banineme
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 32 - Issue 1
A Reshadsedghi; F. Amirshaghaghi; A.A. Solhjoo; H.R. Sadeghnejhad; F Ranjbar; M. Saati
Volume 33 - Issue 1
Volume 34 - Issue 1
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 75-86
Abstract
Chemical spraying is one of the important field operations in wheat production. Farmers usually use lance sprayers, micronair sprayer and atomizer sprayer (motorized knapsack mist blower) in order to control the sunn pest when wheat plant is reach to a desire high. Sunn pest damaged on wheat plant ...
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Chemical spraying is one of the important field operations in wheat production. Farmers usually use lance sprayers, micronair sprayer and atomizer sprayer (motorized knapsack mist blower) in order to control the sunn pest when wheat plant is reach to a desire high. Sunn pest damaged on wheat plant lead to a serious problem in which when targeted plants spray with chemical, the sunn population keep protecting themselves by moving down ward to the lower parts of plant stem. The above mentioned sprayers can not be used to spray with in wheat canopies, while it has been shown that a modified atomizer sprayer is capable of targeting the lower portion of wheat canopies. In this study a conventional atomizer sprayer was manipulated with an boom type to provide a modified atomizer sprayer. Then the modified atomizer sprayer was used to compare with lance atomizer and micronair sprayers in relation to chemical spraying efficiency for controlling the sunn pest damaged in wheat production. The experimental design was setup randomized completed block design (RCBD) with three replications. Results showed that modified atomizer and lance were the first and last sprayers which had lethal effects of 92.6% and 46.5% respectively on the sunn pest at the 5% confidence level. Amount of drifting were 43.1% and 8.3% mioconair and modified atomizer sprayers respectively, at the 1% confidence level. The least amount of solution consumption (11.4 lit/ha.) and the best spraying uniformity were occurred under micronair sprayer operation.VMD and NMD were 388 µm and 286 µm for micronair sprayer respectively. When plant stand was evaluated, there was not any significant difference among sprayer systems in regard to crop lost, except for the lance sprayer which has showed 5.6% crop damaging at the 1% confidence level. Findings in the present study indicated that modified atomizer sprayer is capable of covering more spaces at the middle and bottom of plant canopies with high density (droplets / square cm) than other sprayers. Boom modified atomizer sprayer is strongly recommended as the sunn pest controller in wheat crop, when the plants reached to desirable height.
Volume 36 - Issue 1
Elahe Hasanzade; Mehdi Ghajar Sepanlou; Mohammad Bahmanyar
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 77-85
Abstract
In order to study the effect of potassium and manure fertilizer on yield and concentration of macro elements in leaf and grain of wheat (N-81-18 cultivar) under water stress, a pot experiment was conducted in split plot based on randomized complete design with four replications in 2009-2010 crop years. ...
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In order to study the effect of potassium and manure fertilizer on yield and concentration of macro elements in leaf and grain of wheat (N-81-18 cultivar) under water stress, a pot experiment was conducted in split plot based on randomized complete design with four replications in 2009-2010 crop years. The main factor was inclusive irrigation after depletion of 75, 50 and 25 percent of available water, and the subsidiary factor was inclusive potassium sulfate in three levels (0, 300 and 600 kg/ha) as well as manure fertilizer in three levels (0, 20 and 40 ton/ha). Results indicated that irrigation treatment had a significant effect on grain yield and elements of nitrogen, phosphorous and potassium in leaf and grain at p-1 manure fertilizer and the greatest amount of phosphorous of leaf was observed with consumption of 20 and 40 tons ha-1of manure fertilizer. The maximum amount of grain yield was achieved in irrigation treatment after depletion of 25% available water and usage of 40 ton ha-1manure fertilizer. Grain potassium was increased with the consumption of 300 and 600 kg/ha-1 potassium sulfate.
Volume 37 - Issue 1
Land Evaluation and Suitability
V. Shahrokh; S. Ayoubi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 77-92
Abstract
This study was conducted to evaluate land suitability in Zarinshahr and Mobarakeh areas located in Isfahan Province using Analytical Hierarchy Process (AHP) technique. The hierarchy structure for evaluation was established to select the proper land use for 32 land units. Two alternative land utilization ...
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This study was conducted to evaluate land suitability in Zarinshahr and Mobarakeh areas located in Isfahan Province using Analytical Hierarchy Process (AHP) technique. The hierarchy structure for evaluation was established to select the proper land use for 32 land units. Two alternative land utilization types (the cultivation of wheat and rice) were selected at the lowest level. The intermediate levels of the hierarchy were comprised of seven criteria for evaluating the alternative land uses including soil, climate, gross income, water resources, market, physical environmental impacts and chemical environmental impacts. The weight for each element was calculated using 30 questionnaires which were completed by experts and software EXPERT CHOICE 2000. Then the overall weight for each land use was obtained by multiplying standardized attributes and local weights. The results showed that maximum and minimum calculated land indices for wheat cultivation were 77.4 (unit 2-3) and 18.86 (unit 4-9) and for rice 26.85 (unit 4-10) and 7.43 (unit 4-11), respectively. The climate suitability was the most important factor for selecting the proper land use, followed by soil suitability. The least importance was contributed to market accessibility. The inconsistency ratio related for all the matrices was 9 percent. The results of this study showed that the cultivation of wheat has higher performance for production in all land units.
Volume 33 - Issue 2
Volume 36 - Issue 2
Mohammad Ebrahimi; Seyed Saeid Mohtasebi; Shahin Rafiee; Amin Nasiri; Soleiman Hosseinpour
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 81-92
Abstract
This study was investigated the effective parameters on the banana slices shrinkage during drying, using the response surface technique. In this study, the banana slices were dried using a thin-layer dryer made based on a computer vision system. Therefore, the shrinkage of the slices was determined using ...
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This study was investigated the effective parameters on the banana slices shrinkage during drying, using the response surface technique. In this study, the banana slices were dried using a thin-layer dryer made based on a computer vision system. Therefore, the shrinkage of the slices was determined using an image processing technique in the MATLAB environment. The response surface technique, central composite diagram (CCD) with four parameters, was used to investigate the effect of drying time, drying temperature, slice thickness and air velocity during the drying process (as the process parameters) on the shrinkage (as the process response). The second-order model was selected to describe the shrinkage as a function of the independent parameters (time, temperature, slice thickness and air velocity) due to RMSE=0.033 and R2=0.951. The results showed that the drying time, drying temperature, slice thickness and air velocity had the most effect on the banana slices shrinkage, respectively.
Volume 35 - Issue 2
Davoud Ghanbarian
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 83-96
Abstract
Iran, with more than 90% of world production, is known as the main saffron producer. This plant is sterile and the saffron proliferation is possible only via cultivation of corms. One of the most problems in saffron cultivation is the yield reduction due to planting of small corms. In this research, ...
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Iran, with more than 90% of world production, is known as the main saffron producer. This plant is sterile and the saffron proliferation is possible only via cultivation of corms. One of the most problems in saffron cultivation is the yield reduction due to planting of small corms. In this research, a new saffron corm-grading machine is introduced. The machine includes a rotating drum, which is made of adjustable longitudinal rods. The small and unusable corms are separated via passing them between gaps of the rods. The physical properties of corms were determined and used to calculate gaps dimensions. The effective parameters in machine performance were: rotating drum speed (n), gradient of drum (α), and feeding rate (q). The response surface methodology (RSM) was used to optimize the parameters. An acceptable sizing accuracy of 79% were obtained at n= 33.85 rpm, α=4º, and q=340.1 kg/h as optimum conditions.
Volume 34 - Issue 2
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 85-96
Abstract
In order to determine the efficiency and appropriate levels of two biofertilizers including municipal solid waste compost and vermicompost on improving nutrient availability, growth and yield of canola under drought stress conditions, an experiment was conducted as factorial arrangement based on randomized ...
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In order to determine the efficiency and appropriate levels of two biofertilizers including municipal solid waste compost and vermicompost on improving nutrient availability, growth and yield of canola under drought stress conditions, an experiment was conducted as factorial arrangement based on randomized complete block design with four replications. Treatments consisted of three levels of drought stress, including no stress, mild stress and severe stress conditions, and biofertilizer combination in five levels including control, application of municipal solid waste compost at two and four percent levels and application of vermicompost at two and four percent. Results showed that the effect of stress and biofertilizer levels on nutrient uptake, growth, and yield was significant. The interaction of drought stress and biofertilizer had significantly affected all traits except nitrogen and zinc percent. The results of mean comparison indicated that the mild and severe stress significantly reduced nitrogen, phosphorous, iron percentage and grain yield of canola and increased potassium and sodium percentage in shoot in comparison with the control group. Application of four percent vermicompost resulted in an increase in biomass, yield and nutrient uptake except zinc, under no stress, mild and severe drought stress compared to other biofertilizer treatments. Overall, it could be concluded that biofertilizers, especially vermicompost, positively affected plant growth under drought stress conditions.
Volume 41 - Issue 3
Agricultural Machinery
Mohammad Amin Asoodar; Afshin Marzban; Fatemeh Afsharnia
Abstract
Introduction Wheat is the main food commodity of Iranian population and major cultivating crop, grown on nearly half of the country’s rain-fed area as well as one-third of the irrigated area. Despite the availability of high yielding cultivars for different climates, the average wheat grain yield ...
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Introduction Wheat is the main food commodity of Iranian population and major cultivating crop, grown on nearly half of the country’s rain-fed area as well as one-third of the irrigated area. Despite the availability of high yielding cultivars for different climates, the average wheat grain yield in the country is around 3527 kg ha-1. Lower wheat grain yield could be due to unavailability of recommended varieties seed, delay in planting, inappropriate planting methods, excess use of fertilizers and inefficient water management. Irrigated wheat production in arid and semi-arid regions of Iran is generally practiced under conventional tillage systems. Crop producers in southwestern part of Iran are traditionally using conventional tillage (plowing with moldboard plow followed by double disking) for cultivating various crops. Most of the farmers use grain drills for sowing wheat because of uniformity of planting depth as compared to seed spreaders. The aims of the study were to determine whether different methods of sowing, such as grain drills (followed by flooding irrigation), row crop planting, and combination of furrowers (75 and 60 cm) and seeders (12 cm of sowing space) alter the agronomic performance of winter wheat. Therefore, selection of suitable sowing method plays an important role in the placement of seed at proper depth, which ensures better emergence and subsequent crop growth. Material and methods The study was conducted on a silt clay loam soil (Carbonatic Typic Torrifluvent) in research farms of Ramin Agriculture and Natural Resources University, Ahvaz, Iran, with wheat-wheat- corn crop rotation. The soil was representative of a large area of arable land in the Khuzestan province. Conventional tillage was practiced by moldboard plow ( 25 cm depth) followed by disc harrow twice (nearly 10 cm depth). The two year experiment was conducted based on completely randomized block design in four replicates. 140 kg/ha of wheat (Triticum aestivum L), Chenab cultivar was sown at 50 mm depth for all treatments. The experimental treatments were 20 furrow opener rain drill with 12 cm line space (P), combination of grain drill-furrower (PF60 and PF75) with 60 and 75 cm furrow spaces, also furrower-grain drill (FP60 and FP75 cm) and furrower –grain drill with 3 planted rows on beds (FP3_60 and FP3_75 cm). Soil conductivity of the experimental field (plots) ranged from 1.2 to 3.3 ds mG. The soil texture was silty clay loam with the range of clay content from 34 to36%, and N, P and K contents of the soil were 0.8 to 1, 6.1 to 16.2 and 117 to 192 mg kgG, respectively. Results and discussion Wheat grain yield obtained from all treatments was different; however, harvested grain after FP_75 was the highest compared to others. The highest amount of yield was 5966.7 kg/ha for the first year and 5070 kg/ha for the second year compared to simple planting (P) which was the lowest (4883 and 4271 kg/ha respectively for 2 interval years). Analysis of variance for grain yield indicated that FP-75 had a significant difference (p < 0.01) as compared to others, but grain yield for furrow spaces from 60 to 75 cm was not significantly different. However, the use of furrowers showed significant effects on wheat grain yield. Crop yield and biomass were shown to be different where the furrow was made before sowing. The use of grain drills without furrowers had a great negative effect on crop biomass and grain yield. The results obtained from the second year were similar to the first year. The application of furrow before sowing showed maximum crop yield and biomass, so that the highest and the lowest biomass belonged to FP-75 with 14817 kg ha-1 and P with 11731 kg ha-1, respectively. The harvest index was not significantly different among treatments. Similar results were obtained in wheat plots after harvesting. Conclusion The overall results from this study indicated that the values of crop yield and biomass were maximum where the furrow was made before sowing, as FP-75 treatment had the highest yield. So regarding non-problem of soil salinity in the north of Khuzestan, the use of furrow before sowing can be considered as an appropriate tillage and sowing system for wheat production in the semi-arid region.
Volume 37 - Issue 2
Plant Nutrition, Soil Fertility and Fertilizers
G. Roshani; A. Gharanjiki
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 87-99
Abstract
The fertility maps are useful tools to know about the land resources. These maps are essential to do a correct fertilizer recommendation, monitoring the changes of soil fertility level and also to do prediction of toxicity or deficiency of necessary plants nutritional elements in the soil. The present ...
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The fertility maps are useful tools to know about the land resources. These maps are essential to do a correct fertilizer recommendation, monitoring the changes of soil fertility level and also to do prediction of toxicity or deficiency of necessary plants nutritional elements in the soil. The present research was carried out to digital mapping of macro and micro elements as well as some important physical and chemical properties of the soil for agricultural service centers of Golestan province to optimize the use of chemical fertilizers in operating plan pattern. The studied areas were under irrigated and rain-fed wheat cultivation and the total surface area was about 520000 hectares. Using based maps with the scale of 1: 50,000, the area was divided into 5200 grids each having one kilometer square area. Using Global Positioning System (GPS) instrument a composite soil sample was taken from the center of any grid and analyzed for major macro- and micronutrients as well as physical and chemical properties of the soil namely; pH, EC,TNV, sand, silt and clay contents. At the time of sampling, some additional information like latitude, longitude, elevation, owner's name, date of sampling, kind of water resources, possibility of water logging, crop history (present and previous) was collected and recorded. After getting the laboratory results, for the above stated data sets, an electronic layer was created for any particular parameter and after doing interpolation, the layers were polygonized. Anisotropy of the data sets in different directions was evaluated by the help of variogram surface operation. Then spatial correlation of each data set was calculated. After variogram analysis, spatial variation of the data sets was studied and a suitable model was selected. Finally, through point interpolation using kriging technique, the digital map of each parameter was established.
Volume 39 - Issue 2
S Rostami; M Eslami; M. Kiani Deh Kiani
Volume 41 - Issue 1
Land Evaluation and Suitability
Anahid Salmanpour; Mohammad Hassan Salehi; Jahangard Mohammadi; Abdolmohammad Mehnatkesh; Sayyed-Hassan Tabatabaei
Abstract
Introduction One of the objectives of land evaluation method is determining the land suitability degree and class in case of making any changes, including causing elimination or limitation. Thus, as an example, if it could be possible to predict changes in soil salinity for the future, any changes in ...
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Introduction One of the objectives of land evaluation method is determining the land suitability degree and class in case of making any changes, including causing elimination or limitation. Thus, as an example, if it could be possible to predict changes in soil salinity for the future, any changes in land suitability class can be investigated based on the predicted variations over time.The most important crops in Neyriz area are wheat and barley. Unfortunately, over the past two decades, improper agricultural management caused reduction and salinization of irrigation water in this region. To this end, the present study was performed to investigate the possibility of changes in the class or degree of land suitability in case of variations in soil electrical conductivity due to irrigation with saline water in Neyriz, for the next 10 years. Materials and Methods In three soil map units in three regions consisting of Deh-Fazel, Tal-Mahtabi and Nasir Abad, wheat and barley fields were selected and representative pedons were excavated, described and classified. Soil and water samples were obtained and necessary analyses and soil humidity and salinity, hydraulic conductivity and bulk density and water electrical conductivity were determined. Crop yields were evaluated by 1×1 quadrate, soil surface layer hydraulic conductivity was carried out by guelph permeameter and the volume of irrigation water was measured according to pipe discharge in each farm. Soil retention curve was calculated for all soil layers using sand box and pressure plate. van Genuchten equation parameters were gained using RETC software. Afterward, solute transport modeling was done using the software Hydrus and its results were validated using four statistical parameters including Coefficient of determination (R2), Root Mean Square Error (RMSE), Model efficiency (EF) and Coefficient of Residual Mass (CRM) to investigate the possible variation in soil salinity during the next 10 years, the data of the studied period of the crop year between 1392 and 1393 was repeated for 10 years. Qualitative and quantitative land evaluation was performed by standards methods. Finally, the Hydrus results were compared with salinity maps of Neyriz area which were calculated and obtained in the previous research from Landsat images bands for the past 20 years. Results and Discussion Based on the results, climate suitability class in Neyriz area was suitable (S1) for wheat and relatively suitable (S2) for barley. The limiting factor for barley was the average of maximum temperature in the coldest month for barley. The soil suitability class was suitable (S1) for both crops (wheat and barley) in all farms. Therefore, the land suitability in the studied farmlands was S1 for the wheat and S2 for the barley. Results also revealed that the values for potential production were 10723 and 8677.5 Kg(grain)ha-1 for wheat and barley and for critical production were 1167 and 1297.6 Kg(grain) ha-1 for wheat and barley, respectively in the farms. Amongst the farmlands, only a barley farm which was located in Tal-Mahtabi had the S1 quantitative suitability class and others had S2. The results also showed that if all other conditions like volume and the quality of the irrigation water, precipitation, temperature and evaporation remain constant over the next 10 years, land suitability class will not change but land suitability degree will decrease gradually over time. The validation of the Hydrus model, based on the RMSE values, revealed that the predicted soil salinity and the observed value were very similar and the model had good ability in estimating and modeling soil salinity in the studied area. Comparing the results of modeling and soil salinity maps over the last 20 years have confirmed this trend. Based on the satellite salinity maps, the soil salinity of the studied fields has increased slightly from 2 to 4 dSm-1 between the years 1374 and 1393. Hence it can be concluded that the prediction of Hydrus model about gradual rise in predicted soil salinity and land suitability degree during the next 10 years is acceptable. Conclusion The present study showed that climate and land suitability class in Neyriz area was suitable and relatively suitable for wheat and barley, respectively. Solute transport modeling showed that land suitability degree will decrease gradually and soil quality will decline over time by assuming constant irrigation and precipitation condition over the next 10 years. Therefore, preventing the expansion of soil salinity and degrading agricultural lands require serious considerations of the authorities in the crisis Managements.
Volume 42 - Issue 4
F. Torkamani; H. Piri Sahragard; M.R. Pahlavan Rad; M. Nohtani
Abstract
Introduction Spatial variations of soil properties is a natural event, which recognizing these changes is inevitable in order to planning and right management of both agricultural and natural resources. Soil organic carbon (SOC) is the most important factor in soil fertility and quality, climate change ...
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Introduction Spatial variations of soil properties is a natural event, which recognizing these changes is inevitable in order to planning and right management of both agricultural and natural resources. Soil organic carbon (SOC) is the most important factor in soil fertility and quality, climate change and reduction of greenhouse gas emissions. Furthermore, evaluating the rates and spatial distribution of the soil properties, land improvement and restoration can be traced from the carbon sequestration index. According to the above, providing quantitative and qualitative conservation of soil properties such as SOC can be considered an effective way to achieve sustainable development of natural and environmental resources. Digital soil mapping (DSM) can determine the spatial variations of soil organic carbon by exploring the relationship between soil properties and effective environmental variables. Different statistical models such as regression trees and random forest are used in order to communicate between soil characteristics and its spatial distribution. The present study was carried out to investigate the spatial distribution of SOC, as well as, to determine the most important variables affecting their prediction in Ravang watershed in Minab County. Materials and MethodsRavang watershed with an area of 13821.6 hectares is located in Hormozgan province, Minab city. The maximum and minimum elevations are 357 and 33 meters, respectively. Digital Elevation Model of Ravang watershed was used to extract 17 environmental covariates (such as elevation, aspect, slope, valley depth,…) by SAGA software (http://www.gdem.aster.ersdac.or). Moreover, two environmental covariates related to remote sensing including Normalized Difference Salinity Index (NDSI) and Normalized Difference Vegetation Index (NDVI) were determined in the study area. In addition, the maps of land use, sand, silt, clay and pH were used as covariates in modeling. In order to determining the location of sampling points, the conditioned hyper-cube technique was used. After determining of soil sample location, field sampling was carried out at a depth of 0-30 cm. then, 100 soil samples were taken and the amount of SOC was measured. Random forest model was applied to the relationship between SOC and covariates. The model includes two user-defined parameters, including the number of variables used in the construction of each tree, which expresses the power of each independent tree and the number of trees in each forest. Considering the strength of independent trees, the predictive accuracy of the model increases, conversely, the correlation between them will decrease. The accuracy of the soil organic carbon distribution was also evaluated using root mean square error (RMSE), mean error (ME) and correlation coefficient (R2), which were determined. Results and Discussion Based on the present study results, elevation, soil silt and sand maps, channel network base level, slope and NDVI are the most important factors on predicting the of SOC variations. The results indicated that RMSE, ME and R2 were 0.36, 0.26 and 0.38, respectively .Results also showed that affecting erosion and sediment, as well as, human effect, have the most impact on the SOC soil spatial distribution in the Ravang watershed. Moreover, result show SOC deficiency in the soil of Ravang watershed due to high salinity, low percent of vegetation cover and land use changes. In addition, drought intensifying and decrease in precipitation have reduced SOC content, which itself causes changes in the texture and chemical properties of the soil and, as a consequence, makes them more susceptible to erosion. Conclusion The variability of SOC is very high in the study area because of intensive water erosion and land use change. Overall, the results of the present study indicated that the critical condition of soil organic carbon in the Ravang watershed, which requires a comprehensive management of the region's water and soil resources to improve soil conditions and increase the reserves of this important and influential variable in the soil structure. On the other hand, despite of the acceptable performance of the random forest model in estimating of soil properties, due to high variability of some soil properties, model prediction performance may be decreased.
Volume 39 - Issue 1
S. Firouzi
Abstract
Introduction The hazelnut (Corylus avellana L.) is one of the most cultivated and consumed nuts in the world, not only as a fruit but also as a main constituent into a wide range of manufactured food products. Iran after Turkey, Italy, USA, Azerbaijan, Georgia and China, is the world's seventh largest ...
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Introduction The hazelnut (Corylus avellana L.) is one of the most cultivated and consumed nuts in the world, not only as a fruit but also as a main constituent into a wide range of manufactured food products. Iran after Turkey, Italy, USA, Azerbaijan, Georgia and China, is the world's seventh largest producer of hazelnuts. Guilan province is the largest producer of hazelnuts in Iran. More than 90 percent of hazelnut of this province, after removing the initial green shell is sold at low prices. Therefore, design and optimization of harvesting machines and processing equipment to produce this product is important. Thus, the aim of this research was to study the physical, mechanical and nutritional properties of three common hazelnut cultivars in Guilan province of Iran. Materials and Methods In this study, two common local cultivars of hazelnut in north of Iran (Gerd and Badami), and an improved variety namely Keshavarzi were considered for all experiments. Experimental samples were supplied from Eshkevarat region as the major hazelnut producing part of Guilan province. All physical, mechanical and nutritional properties of both the hazelnut and kernel samples were measured and computed at moisture content of 2.3–3.3% dry basis. Nutritional properties including crude protein, oil, crude fiber, ash, dry matter, carbohydrate and some minerals, i.e. N, P, K, Mn, Fe, and Zn contents of hazelnuts, were measured based on the standard methods. All nutritional and mineral data were analyzed through a completely randomized design with three replications. Physical properties including dimensional properties, bulk and true densities, porosity, natural angle of repose, terminal velocity, and coefficient of friction on plywood structural surface and galvanized iron sheet were measured based on the standard procedures. All physical data were analyzed through a completely randomized design with five replications. Mechanical properties including rupture force, deformation and energy absorbed at rupture point along with the hardness of nuts were determined by applying force to three major perpendicular axes of all nut samples. The energy absorbed for rupture nuts was determined by measuring the area beneath the strain-stress curves and hardness of nuts was computed as the ratio of rupture force to the corresponding value of deformation at rupture instant. All mechanical data were analyzed through a completely randomized design with five replications. Results and Discussion According to the variance analyses, there were significant differences between the hazelnut cultivars in terms of crude protein and fiber, ash and carbohydrate contents (pStudy of the physical properties showed that there were significant differences among all dimensional characteristics of the hazelnut cultivars and their fruits. All dimensional characteristics of hazelnut cultivars were significantly higher than those of their fruits. All linear dimensions of Keshavarzi hazelnut cultivar were significantly more than those of local cultivars of Badami and Gerd, while there were no significant differences among length and width of Keshavarzi cultivar and Badami local cultivar. Bulk density, porosity, dynamic natural angle of repose, terminal velocity, and static coefficient of friction on plywood sheet of the hazelnut cultivars were found to be statistically significant at five percent level and p<0.001, but there was no significant difference among true densities of cultivars. There were significant differences between values of bulk density, dynamic natural angle of repose, terminal velocities, and coefficient of friction on plywood structural surface, but no significant differences were seen for true density, porosity, and coefficient of friction on galvanized sheet. Differences among the majority of physical characteristics of hazelnut cultivars and their fruits can be used in design and adjustment of harvesting and processing equipment. Different data were recorded for mechanical properties in various axes of all hazelnut varieties. In more spherical cultivars, the mechanical properties in three dimensional axes were close to one another. The data of rupture force, deformation and energy absorbed at rupture instant, and hardness of nuts can be used for design and adjustment of hazelnut crackers. Conclusion There were significant differences between a large number of physical and mechanical properties of three common hazelnut varieties in Guilan province, Iran. The differences among the engineering characteristics should be used in design and optimizing of hazelnut machineries and processing equipment. The results showed that the improved hazelnut cultivar of Keshavazi had no considerable superiority to landraces cultivars of Gerd and Badami in terms of nutritional and mineral contents. Therefore, it is essential that along with the physical superiority of alternative hazelnut cultivars, their nutritional and mineral advantages be considered by the agricultural experts in Guilan province, Iran.
Volume 38 - Issue 1
M Aalipour Shehni; A Farrokhian Firouzi; A Koraie; H Motamedi
Abstract
Introduction: Preferential flow is one of the major processes influencing the rapid movement of pollutants to ground water. Macropores created by plant roots provide pathways for rapid transport of pollutants in a soil profile. The growth of plant roots into soil causes creation of big pores that ...
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Introduction: Preferential flow is one of the major processes influencing the rapid movement of pollutants to ground water. Macropores created by plant roots provide pathways for rapid transport of pollutants in a soil profile. The growth of plant roots into soil causes creation of big pores that improve water movement and solute transport through soil profile. Field soils or undisturbed soils have many different types of macropores. These macropores may contribute to preferential flow. Therefore, to better evaluate the macropores that are created by plant root in preferential flow, it is essential to isolate the macropore and examine that macropore individually. The main objective of this study was quantitative investigation of the effect of plant root on chloride transport through soil profile under a saturated condition. Materials and methods: In order to investigate the influence of corn root system on soil hydraulic properties and chloride transport in soil an experiment was conducted in completely randomized design. The treatments were prepared as bare soil (control), soil with corn (Zea mays L.) root and soil with corn root 3 months after harvesting in 9 soil columns packed uniformly with loamy sand-textured soil (Bulk density=1.48 g/cm3). The particle size distribution and organic carbon of soil were determined. Saturated hydraulic conductivity was measured for each soil column using constant head method. The breakthrough curves of chloride were measured under saturated condition (constant head method). Before starting the displacement experiment, the soil columns were subjected to capillary saturation from the bottom with 0.01 M CaCl2 for two consecutive days. In order to establish steady state flow conditions, the soil columns were irrigated with a 0.01 M CaCl2 solution at a constant rate and less than 0.5 cm of water was ponded above the soil surface. The chloride concentration in the outflow samples was measured using an electrical conductivity sensor. For measuring the chloride breakthrough curves (BTCs), the 0.01 M CaCl2 solution was replaced by a 0.05 M CaCl2 solution. The chloride transport in the soil columns was simulated using CXTFIT Convection-Dispersion Equation (CDE) and Mobile-Immobile Model (MIM). A nonlinear least-squares program was used to fit the convection-dispersion equation (CDE) and the physical nonequilibrium model (MIM) to the experimental data. Results and Discussion: The research result showed that macropores created by growing and remaining of plant root (Zea mayz L.) have a significant effect on soil hydraulic properties and solute transport.The results indicated that there is significant difference between soil hydraulic properties (saturated hydraulic conductivity and Darcy's flux density) in different treatments (p<0.05). Darcy's flux density indices in soil columns were 1.23 and 1.31 times more than control treatment in plant root and plant root 3 months after harvesting treatments, respectively. The two models (CDE and MIM) fit the BTCs curve data well. Models fits were excellent with R2 values from 0.85 to 0.97. The CDE parameters (D and ν) in treatments had significant difference (p<0.05). Dispersion coefficient (D) values were 2.65 and 3.71 times more than control treatment in plant root and plant root after 3 months harvest treatments, respectively. Pore water velocity (ν) values were 1.36 and 1.52 times more than control treatment in the mentioned treatments.The breakthrough curves of soil with corn (Zea mays L.) root and soil with corn root after 3 months harvest treatments were asymmetrical in shape (asymmetrical with respect to the C/C0=0.5 point on the BTCs). The relative concentration C/C0 in the effluent is obtained before one pore volume of chloride is passed through the soil column. Conclusion: High flow velocity, saturated hydraulic conductivity (Ks) and dispersion coefficient (D) of the soil columns treated with plant root or with plant root after 3 months harvest indicated the presence of macropores in the soil that is created by deep corn root system. The early breakthrough of chloride BTCs reveals the existence of preferential flow, suggesting that a portion of chloride moves through soil macropores. The occurrences of preferential flow were attributed to well-connected macropores created by plant roots and decayed corn root 3 months after harvesting. Furthermore, the results of this research indicated that when considering solute transport in agricultural soil the effect of plant root needs to be considered.
Volume 38 - Issue 2
Y. Abbaspour-Gilandeh; A. A. Khalifeh; S. Ghavami-Jolandan
Volume 42 - Issue 1
Biofuels
Mostafa Parsaee; Mostafa Kiani Deh Kiani; Zabiollah Mahdavifar
Abstract
Introduction Anaerobic digestion has progressed rapidly since the late 1960s. With the progress of the anaerobic fermentation process in the world, anaerobic reactors have been developed to digest different types of organic wastes in each country. So various types of reactors have been built, and that ...
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Introduction Anaerobic digestion has progressed rapidly since the late 1960s. With the progress of the anaerobic fermentation process in the world, anaerobic reactors have been developed to digest different types of organic wastes in each country. So various types of reactors have been built, and that they have been in different shapes, dimensions, and operating conditions. One of these reactors is the static granular bed reactor (SGBR). SGBR with its granular bed digests a substrate in less hydraulic retention time (HRT). SGBR is a downstream reactor that consists of active anaerobic granules. The biomass contacts the granular surfaces and does not require the use of mixers, gas, solid, and a separator. The reactor startup is very short since there is no need for some operations, such as extra time to grow microorganisms in the granule. One of the most important residues in the alcohol production plant from molasses is vinesse which has become a major problem in this industry. The conversion of vinasse to biogas and using it to supply the energy of the industry is one of the basic ways to solve this problem. Several studies have been conducted in this field by using various reactors, but there is no research about SGBR. In this study, an SGBR producing biogas from vinasse has been designed and constructed. Also, the performance of the reactor was investigated at three HRTs (2, 3, and 4 days) and the thermophile temperature of 55 °C. Materials and Methods The best diameter to height ratio (reactor volume) in the SGBR is 1:7. Accordingly, the shape of the reactor is a pipe. Based on the volume of the reactor and the maximum pressure inside it, a 4-inch polyethylene tube with a height of 1 meter was selected to carry out the testes. According to the thermophile temperature (55 °C) and the accuracy of the element (0.9 °C), the maximum temperature of the reactor is 329 K. Therefore, the minimum power for obtaining this temperature is 405.316 watts. The water displacement method was used to measure the amount of biogas. An iron sponge was used for removing hydrogen sulfide gas from biogas. Sodium hydroxide solution was used to remove carbon dioxide from biogas. Results and Discussion The reactors were loaded daily with organic matter (86002, 28667, and 21500 mgCOD/L.d) for different HRTs (2, 3, and 4 days). For three HRTs, the amount of methane production was high during the first day which is due to the thermal shock caused by the microorganisms in the granule. Methane production in HRT of 2 days had fewer variations than HRT of 3 and 4 days, and after 13 days, it reached a nearly constant value of 4600 ml/day. For HRT of 3 days, the daily rate of methane production reached a constant value of 4800 ml/day after 12 days and for HRT of 4 days, it reached 4,900 ml/day after 10 days. For HRTs of 2 and 3 days, the rate of methane production per unit of volatile solids had less variation and remained constant approximately after 7 days. The average methane production per unit of volatile solids at HRT of 4 is days higher than the other HRTs. The average methane production for HRTs of 2, 3, and 4 was 379, 380, and 433 CH4 (L)/VS (kg), respectively. The maximum value of methane production was 582 m3/kgCOD, which was obtained at HRT of 2 days. In this study, 31 liters of methane were produced per one liter of vinasse at HRT of 4 days, which was more than other studies. Conclusion In this study, the required heat power and pressure inside the SGBR laboratory have been calculated. The minimum required heat is 261 watts. Also, this reactor should be able to bear at least 4.34 bar for biogas production. The average amount of methane production per unit of volatile solids was 379, 380, and 433 CH4 (L)/VS (kg) at HRTs of 2, 3, and 4 days, respectively. The maximum amount of produced methane was 582 m3/kgCOD, which was achieved at HRT of 2 days, and the maximum percentage of COD reduction was 39%, which was achieved at HRT of 4 days. In general, the results indicated that SGBR produced higher biogas from vinasse than other reactors, but it is not suitable for reducing pollutions.
Volume 42 - Issue 3
N. Monjezi
Abstract
Introduction Currently, musculoskeletal disorders are one of the most common occupational diseases and one of the most common causes of absenteeism, which leads to a decrease in productivity. Postural assessment methods are considered pivotal in the investigation of the risks of developing job-related ...
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Introduction Currently, musculoskeletal disorders are one of the most common occupational diseases and one of the most common causes of absenteeism, which leads to a decrease in productivity. Postural assessment methods are considered pivotal in the investigation of the risks of developing job-related musculoskeletal disorders. Various approaches are presented to assess the risk of injury in inappropriate postures. Agriculture is one of the most crucial sectors in both the developing and the developed countries since it ensures the food security of the country. In the process of producing sugarcane, a significant part of the stages of cutting, planting, and harvesting is done manually. A low level of knowledge about the correct condition of the body during work is one of the problems of farmers. Therefore, body status assessment methods are considered as the basis for assessing the risk of musculoskeletal disorders associated with work. Materials and Methods This research was carried out with the aim of analyzing the risk factors of occupational skeletal musculoskeletal injuries in sugar cane farmers using QEC method and Nordic questionnaire. The quick exposure checklist (QEC) quickly assesses the exposure to risks for work-related musculoskeletal disorders (WMSDs). QEC is based on the practitioners’ needs and research on major WMSD risk factors. The Nordic body map is given to the participants to be filled out with the assist of a student research assistant when needed. However, due to practical reasons, most participants are interviewed using the semi-structured method by a student research assistant. The Nordic body map consists of 28 parts of the body that must be rated based on the symptoms. Examples of the body parts are the right shoulder, upper arm, etc. The postures of 50 cutting workers, 200 planting workers, and 50 harvesting workers were selected by random sampling and analyzed using QEC2003 software. Results and Discussion According to the results of the Nordic questionnaire in manual cutting sugarcane, the most prevalent signs of musculoskeletal disorders were in the waist (80%), wrists and hands (78%), knees (74%), and feet (70%). In manual planting sugarcane, the most prevalent signs of musculoskeletal disorders were in the areas of the waist (89%), back (86.5%), and knee (84.5%), respectively. The findings also indicate that in the manual harvesting operations, the most prevalent signs of musculoskeletal disorders were the wrist and hand (88%), waist (84%), and foot (80%). The results of the Nordic questionnaire show that most disadvantages of cutting, planting, and harvesting in workers are visible in the lower back (80%), lower back (89%), and wrist/hand (88%), respectively. The prevalence of skeletal musculoskeletal disorders, especially in the waist, was observed among a high number of sugarcane producers. The results also showed that in the QEC method, in cutting, planting, and harvesting 44, 62, and 59 percent of workers’ postures were placed in the most critical group. In manual cutting of sugarcane, 30 percent of the workers were at the high-risk level and 44 percent of workers were at high risk, indicating the high risk of this operation, and that better preventive measures should begin as soon as possible. In the QEC method for manual planting of sugarcane, 7% of the postures of workers is acceptable and their risk is very low. Work posture for 9.5% of people requires more research and attention, and 21.5% of workers must be treated fairly fast. 62% of the postures of workers need to be corrected promptly. In the QEC method for manual harvesting of sugarcane, the posture requires 14% more research and attention, and 28% of workers should be treated fairly quickly. For 59% of postoperative workers, work should be promptly corrected. The QEC analysis showed that some of the work postures posed greater risks of MSDs to the workers with QEC scores. QEC helps to prevent many kinds of WMSDs from developing and educates users about WMSD risks in their workplaces. Conclusion The study has identified the body parts and tasks of the workers exposed to ergonomic risks through the Nordic questionnaire and the QEC method, respectively. Results from the study showed that the majority of the workers were having WMSDs.The physical condition of sugar cane production workers needs to be corrected. The ergonomic training course can have an impact on improving the working conditions of workers, but it is not enough, and it is a must-have for the sugar agro-industry to move towards all mechanized operations.
Volume 41 - Issue 4
Plant Nutrition, Soil Fertility and Fertilizers
Soraya Taheri; abdolmajid ronaghi; Reza Ghasemi; Sedigheh Safarzadeh Shirazi
Abstract
Introduction Zinc deficiency is aggravated mainly in arid and semi-arid regions, due to low organic matter and soil moisture as well as high levels of pH and salinity. Maize which serves as staple food is sensitive to Zn deficiency. One of the mechanisms by which plants can adapt to nutrient deficient ...
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Introduction Zinc deficiency is aggravated mainly in arid and semi-arid regions, due to low organic matter and soil moisture as well as high levels of pH and salinity. Maize which serves as staple food is sensitive to Zn deficiency. One of the mechanisms by which plants can adapt to nutrient deficient soils has suggested producing and secreting organic substances, including aliphatic low molecular weight organic acids, into the rhizosphere for mobilization and uptake of nutrients. Under Zn deficiency, plants tend to modify rhizosphere in order to increase Zn phyto-availability. Zinc mobilization efficiency is dependent upon the amount and type of organic acids exuded by plant roots and physiochemical properties of soil. Therefore, the objectives of the present study were to investigate the influence of Zn deficiency on the shoot and root dry matter yields and the release rate of organic acids (malic, citric and acetic acids) commonly identified in root exudations of maize under Zn deficiency conditions. Materials and Methods Seeds of maize (SC703 and SC704) were surface sterilized and germinated in perlite moistened with distilled water. After seven days, the seedlings were transferred to 5-L containers with continuously aerated nutrient solution. Three Zn levels (0, 0.5, and 1 µM) were added to nutrient solutions. Ten weeks after maize emergence, intact plants were removed from nutrient solution and after two hours of the onset of the light period, roots samples were in opaque vessels containing fresh solution. The volume of collected solution was sufficient to submerge the whole maize roots samples. After three hours, roots samples were removed from the vessel and solution containing roots exudates was filtered and frozen at −20 ◦C until analysis of organic acids was performed. Organic acids were analyzed using high performance liquid chromatography (HPLC). Organic acids in the samples were identified by comparison with the retention time and absorption spectra of pure standards including malic, citric and acetic acid. The 1-cm washed root segments were placed in a beaker containing 10 mL deionized water and then root samples were immersed at 30◦C for three h, and then conductivity of solution was measured. The samples were boiled for 2 min, cooled to room temperature (25◦C) and then EC samples were measured. The electrolyte leakage was calculated as follows: Where C1 and C2 are electrical conductivities measured before and after boiling, respectively. Roots and shoot samples were ignited at 580 ◦C in an oven for 5 h and Zn concentration measured using atomic absorption spectroscopy (AAS). Results and Discussion In both genotypes shoot dry matter yield (SDMY) was significantly improved with increasing Zn concentration in nutrient solution. The highest value of SDMY was 19.8 g and belonged to Zn-adequacy level (1 µM) in SC703 genotype which had no significant difference with SC704 under the same treatments. There was no significant difference between Zn-sufficient and Zn-deficiency (0.5 µM) in SDMY in genotype SC703 whereas, a significant difference was observed at the same treatments in genotype SC704. The lowest value of SDMY was 14.7 g and belonged to the Zn-free treatment for genotype SC704. Root dry matter yield (RDMY) significantly increased with increasing Zn concentration in nutrient solution in both genotypes. The highest value of RDMY was 9.6 g and belonged to the treatment of Zn-adequacy for SC703 genotype which had no significant difference with SC704 genotype under the same treatment. The lowest value of RDMY was 4.8 g which was observed in Zn-free treatment for SC704 genotype. Results showed that the rate of organic acid exudation in both Maize genotypes decreased with increasing Zn levels in nutrient solution. The highest rate of MA exudation (6.6 mg /g root dry weight) was observed in Zn-free (Zn0) treatment in SC703 genotype and the lowest rate (1.98 mg g RDW-1) was observed in 1µm Zn treatment in SC704 genotype. Similar to MA, the rate of citric acid (CA) exudation rate significantly decreased with increasing Zn levels in nutrient solution. The highest rate of CA exudation rate was 1.06 (mg gRDW-1) and observed in Zn-free (Zn0) SC703 genotype. The lowest rate of CA was observed in 1µm Zn treatment SC704 genotype 0.2 (mg gRDW-1). The concentration of acetic acid (AA) was below the detection limit of HPLC in Zn sufficient and Zn deficiency treatments. However, AA concentrations in Zn-free were 0.66 and 0.25 (mg gRDW-1), respectively in SC703 and SC704 genotypes. The rate of MA was significantly higher than CA (4times) and AA (15 times higher). All organic acids exudation rate decreased with increasing Zn concentration in nutrient solution. There was a negative relationship between root and shoot Zn concentration with MA and CA exudation rate. MA, CA and AA exudation rate decreased as the concentration of Zn increased in root and shoot of maize. Roots membrane permeability decreased with increasing Zn concentration in nutrients solution which led to the reduction in root exudations. In both maize genotypes, the highest rate of root membrane permeability belonged to the Zn-free treatment (Zn0) which had the highest root exudation of organic acid and the lowest rate was observed in1µM Zn level with the lowest rate of organic acid exudation. It seems that Zn concentration in maize shoot control the release of root exudation of organic acids. In general, based on the results it can be concluded that SC703 genotype was more tolerant to Zn-deficiency compared to SC704 genotype partly due to the higher release rate of root organic acids. Further investigation is required to fully understand the physiology of organic acids release under Zn deficiency conditions.
Volume 42 - Issue 2
Soil Physics, Erosion and Conservation
Vajiheh Dorostkar; Zahra Ganji Norouzi; Safoora Nahidan
Abstract
Introduction Conservation and improvement the soil structural stability play a key role in soil management in agro ecosystems especially in arid and semiarid region with high erosion potential. Soil structure is an important soil physical property and has many effects on other soil physical, chemical ...
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Introduction Conservation and improvement the soil structural stability play a key role in soil management in agro ecosystems especially in arid and semiarid region with high erosion potential. Soil structure is an important soil physical property and has many effects on other soil physical, chemical and biological behaviors such as retention and movement of water, nutrients and pollutions, soil hydraulic and mechanical properties, soil aeration and erosivity. Wetting and drying cycles are one of important environmental factor affecting soil structural stability. Previous studies showed inconsistent results about the positive or negative effects of wetting and drying cycles on soil stability. This study was conducted to investigate the effect of wetting and drying cycles on the soil structural stability in the presence of safflower residues. Materials and Methods The agricultural soil was collected from the soil surface layer (0–20 cm) of Shahrood in Semnan province and passed through a 4 mm sieve. An experiment was conducted including two treatments i.e. number of wetting and drying cycles (0, 1, 2, 4, 8 and 10 cycle) and amount of safflower residues (0, 1 and 2 g 100 g-1 soil ). Plant residues were collected from safflower fields and after drying, milled and passed through a 1 mm sieve. Then crop residues were mixed into soil. The wet and dry cycles were applied during 2 month. In wetting periods the soil was kept in filed capacity and in dry periods the soil was kept in electrical oven in 40°C. The soil organic carbon and soil diluted acid carbohydrate concentration were measured at the end of the experiment. The soil structural stability was measured using high energy moisture curve. The soil drainable pores, soil suction at inflection point, stability index, stability ratio and Dexter's S index were calculated.Results and Discussion The greatest soil organic carbon was observed in control treatment (0 wet and dry cycle) and then it was decreased by increment of cycles in all crop residues levels. These cycles improve the microbial activity during the rewetting process and increase decomposition of crop residues. The soil organic carbon and diluted acid carbohydrate were highest in treatments including 2 g residues 100g-1 in all studied wet and dry cycles. The greatest soil drainable pore volume and the lowest soil suction at inflection point were found in treatment including 4 wet and dry cycles. The results showed that 2 and 4 cycles increased the soil drainable pore volume by 58 and 106 % compared to the control treatment (no applied cycle). More increment of wet and dry cycles decreased the soil drainable pore volume and this factor was declined by 40 % in 10 cycles treatment compared to 4 cycles. It means that wet and dry cycles can improved the soil structure because of rearrangement of soil particles and improvement of soil particle contact points. However, the high number of wet and dry cycles destructed the aggregate and decreased their stability. In addition, the physical protection of soil aggregates from soil organic matters declined through aggregate breakdown. This phenomenon provided fresh organic matter for decomposers and consequently the aggregate stability decreased. Appling only one wet and dry cycle could not significantly improve the stability ratio. This ratio improved considerably when 2 and 4 cycles were used. Following the aggregate breakdown in treatments including more than 4 cycles, the stability ratio decreased in all crop residue levels. Our results showed that the greatest and the lowest volume of coarse and medium pore were observed in 4 and 10 wet and dry cycles treatments but the greatest and the lowest volume of fine pores were observed in 10 and 4 wet and dry cycles treatments. It means that the structural stability improvement during 0-4 cycle changed the pore distribution and made larger pores but the aggregate breakdown with more than 4 cycles changed the pore volume again and increased the portion of finer pores. Conclusion Our results showed that the low number of these cycles can improve the soil aggregation and aggregate stability but the high number of these cycles has negative effect on aggregate stability. However, the presence of organic matter in soil can decreased the negative effect of wet and dry cycles. These results confirmed the importance of incorporating crop residues in to the soils after crop harvest.
Volume 43 - Issue 1
Seyed Ameneh Ghoreishi Amiri; Mojtaba Barani motlagh; Esmaeil Dordipour
Abstract
Introduction: Focusing on population and industrial centers in the different areas has caused the formation of a huge volume of sewage which their treatment (refining) has led to produces a larger volume of sludge so that without any attention to find out the best disposal way, has created various environmental ...
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Introduction: Focusing on population and industrial centers in the different areas has caused the formation of a huge volume of sewage which their treatment (refining) has led to produces a larger volume of sludge so that without any attention to find out the best disposal way, has created various environmental difficulties. One of the economic and efficient ways to use sewage sludge is utilizing them in agriculture. Sewage sludge, due to its large amount of nutrients and organic matters and being less expensive, nowadays it is widely used as a fertilizer and/or amendment of soil physical and chemical properties. In the present study, the effect of different levels of industrial sewage sludge application on the bioavailability and distribution of various forms of iron in spinach plant, Shahr Reza cultivar was evaluated.Materials and Methods: Soil was collected from 0-30 cm depth around Aq Qala industrial town. After air drying, the soil was passed a 2 mm sieve and its physical and chemical properties measured. For this purpose, a completely randomized design with different levels of industrial wastewater sludge (0, 22.5, 45, 90, 180 and 360 ton/ha) was conducted in the form of a pot experiment with 4 replicates in greenhouse of research center of Gorgan Agricultural and Natural Resources Research. The experimental units were pots of 7 kg soil. Then, 20 seeds per pot were planted at 2 cm depth of soil and after two weeks of emergence, the number of shrubs was reduced to 5 plants per pot. Irrigation and weeding were done manually. After the end of the growth period (90 days), the plant samples were digested by dry-digesting method. The concentration of iron in the samples was determined by atomic absorption device (AAS-Unicam-919). Immediately after harvesting, the soil of pots was air-dried and passed through a 2 mm sieve. Then the amount of soil extractable iron by DTPA was read by the atomic absorption device. In addition, Tessier et al. (1979) method was used to investigate the distribution of different forms of iron after sludge application. Statistical analysis of the test data was performed using SAS software and LSD test (5%) was used to compare the means. Also, Graphs were plotted using Excel software.Results and Discussion: The results showed that concentration of iron in the soil and aerial parts of spinach was significantly affected by the sewage sludge application. The highest dry weight of the spinach aerial part with an average of 5.89 g/plant was related to 90 tons/ha sludge treatment and the lowest with an average of 1.07 g/plant was related to the control treatment. Although the application of sludge at high levels such as 180 and 360 t. ha-1 led to a reduction spinach yield, this seems to be due to sludge effects such as the presence of heavy metals, disturbance of soil C/N equilibrium, and especially increase soil salinity. The concentration of iron in spinach aerial parts increased linearly in 22.5, 45, 90, 180, 360 ton/ha sludge treatments, which had an increase of 3.19, 5.16, 12.04, 26.06 and 52.76 percent compared to the control treatment, respectively, while the highest amount of iron uptake with an average of 767.47 mg/kg dry matter obtained in 90 ton/ha sludge treatment and the lowest amount with an average of 124.43 mg/kg dry matter was related to control treatment. The average of iron uptake in the aerial parts of spinach in 180 and 360 t/ha sludge treatments, respectively, was 735.93 and 341.08 mg/kg dry matter, which was 4.28% and 125% lower than 90 t/ha treatment, respectively. The results also showed that application of 360 t/ha sewage sludge increased 73.48% DTPA extractable iron compared to the control treatment. The results of iron fractionation showed that the amounts of all iron components in the soil (except iron and manganese oxides) increased by application of sewage sludge. In the control soil, different iron components were as follows: exchangeable> carbonate> organic> iron and manganese oxides> residual. By applying treatments, the order did not change except that after application of treatments, in all components of iron (except iron and manganese oxides) showed an increase in the amount of each component compared to the control treatment. The correlation between the chemical forms of iron with DTPA-extractable iron and iron concentration of spinach showed that between iron concentration in spinach and extractable iron with DTPA (r= 0.93), exchangeable iron (r= 0.95) and iron bound to the organic fraction (r= 0.98) had a significant and positive correlation at the 1% level and with iron bond to iron and manganese oxides (r= 0.98) had a significant and negative correlation at 1% level which may indicate the role of these forms of iron (DTPA-extractable iron, exchangeable iron and organic-bound iron) in the nutrition of spinach (Spinacia oleracea L.). Increased Fe concentration in plant organs by sewage sludge application may be due to increased concentration of elements in soil and consequently higher uptake of this element by plant.Conclusion: In general, it can be concluded that the application of sewage sludge in high amounts of 180 and 360 ton/ha with the effect on physical and chemical properties of soils such as disturbance of nutrient balance and increasing soil salinity causes a decrease in plant dry weight and the ability of iron uptake in the spinach plant. However, sewage sludge application provides nutrients for plant growth and reduces the economic cost of disposal. However, it is recommended to determine the threshold of toxicity and salinity before application of sewage sludge depending on soil, plant and environmental conditions. More extensive research is also needed to standardize the method and relative amounts of use of this organic amendment.
Volume 40 - Issue 2
Soil Physics, Erosion and Conservation
E. Karami; S. Ghorbani Dashtaki; Bijan Khalilimoghadam
Abstract
Introduction Soil erodibility can be viewed as the integral result of the processes determining the infiltration of rain into the soil and of the processes determining the soil’s resistance to the detachment of its particles and their subsequent transport (Lal, 1988). It is generally considered ...
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Introduction Soil erodibility can be viewed as the integral result of the processes determining the infiltration of rain into the soil and of the processes determining the soil’s resistance to the detachment of its particles and their subsequent transport (Lal, 1988). It is generally considered as an inherent soil property with a constant value for a given soil type and widely adopted as an important factor in soil erosion prediction models, such as the Universal Soil Loss Equation (USLE), and the Revised USLE (RUSLE). The erodibility factor, commonly known as the K factor, in the USLE was defined as the average rate of soil loss per unit of rainfall erosivity index from a cultivated continuous fallow plot, on a 9% slope 22.1 m long. Soil erodibility factor K is not only an internal factor indicating the amount of soil loss, but also the basis for the quantitative study of soil erosion. Soil erodibility is closely related to the basic physicochemical characteristics of soils. The total aggregate content, 1–10 mm aggregate content, aggregation degree, aggregate dispersion coefficient and erosion rate are indexes for the analysis of soil anti-erosion capability. Not only may soil erosion be different for various types of soils, but also it is different for the same type of soil under different climate conditions or land use management. Different land use systems might alter several soil properties and processes. Kosmas et al. (2000) reported that land use change could impact soil physical, chemical, and biological properties. Studies by Duiker et al. (2001) showed that land use changes from natural and semi-natural vegetation to cultivated and grazed lands affect soil bulk density, porosity and water storage, water infiltration and water flow characteristics and surface runoff. Abbaszadeh Afshar et al. (2010) found that organic matter content and bulk density were greater in pasture soils than in dry farm soils. Kay (2000) showed that large aggregate sizes and high organic matter content protect soils against splash detachment. Although there are many studies on land use impacts on soil erodibility, to the best of the authors’ knowledge, no study has of yet been reported on the effects of land use change on soil erodibility in Zayandeh-Rood watershed. Therefore, the objective of this study was to investigate the impacts of different land uses on soil erodibility in a part of Zayandeh-Rood watershed. Materials and Methods For this purpose, soil properties including particle size distribution, gravel percent, bulk density, permeability of soil profile, Structure code and permeability code, organic matter, calcium carbonate equivalent, mean weight diameter of aggregates and surface shear strength were measured. Soil erodibility was measured with a rainfall simulation device with rainfall intensity of 30 mm h-1 and 30 min duration in a plot with 0.25 m2 area and 9% slop in two land uses, namely pasture and degraded pasture. A completely randomized design was used in which soil texture and the land use changes were analyzed. The multiple-linear regression analysis was used to relate soil erodibility factor to different soil parameters. Results and Discussion The influence of land use change on soil erodibility was investigated based on simulated rainfall in field conditions. The findings of this study demonstrated that a considerable amount of soil erodibility occurred in the study region characterized by low organic matter and mismanagement. On average, soil erodibility was significantly affected in the Zayandeh-Rood watershed, Iran, by the land use system (i.e., soil structure and management practices) rather than by the soil textural class. Average soil erodibility was obtained in pasture land use 0.05 (ton h MJ-1 mm-1) and in degraded pasture 0.09 (ton h MJ-1 mm-1). Low soil organic matter content in the degraded pasture land is probably caused by livestock overgrazing and ultimately grazing. Based on the results obtained of the transfer functions in each land uses, it was observed that clay and coarse sand particles (R2=0.86) in pasture land uses and surface shear strength and permeability code (R2=0.90) in degraded-rangeland at the 5% level compared to other soil properties were more suitable parameters for estimating of soil erodibility. Thus, vegetation cover protection was recommended to soil conservation in this region.
Volume 40 - Issue 1
A. Razavi Nasab; A. Fotovat; A.R. Astaraie; A. Tajabadipour
Volume 47 - Issue 1
Soil, Water and Plant Relationships
Hossein Beyrami; Hossein Parvizi; Amir Parnian; Hadis Hatami
Abstract
ABSTRACTIntroductionSoil and water salinization is a worldwide problem, especially in irrigated areas, causing decrease in crop yield and the continuous loss of arable fields. Halophytes are the natural genetic source of salt tolerance traits and can be used for revegetation and remediation of salt-affected ...
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ABSTRACTIntroductionSoil and water salinization is a worldwide problem, especially in irrigated areas, causing decrease in crop yield and the continuous loss of arable fields. Halophytes are the natural genetic source of salt tolerance traits and can be used for revegetation and remediation of salt-affected lands, and also as an alternative crop or biofuel. Due to the limited quality of water resources in the country and considering that the major regions of Iran's area are considered to be arid and semi-arid, it is important to cultivate plants with high tolerance to environmental stresses such as drought and salinity. The quinoa (Chenopodium quinoa Willd.) plant is important because of its ability to be cultivated in saline areas and irrigated with saline water. According to previous research, quinoa is an optional halophyte, and its irrigation is possible up to sea level salinity. Quinoa (Chenopodium quinoa Willd.) is one of the plants that has outstanding economic and agronomic advantages among the crops; it is particularly important in terms of forage production. There is no reliable and accurate information about the amount of water consumption by this plant in Iran. Considering the climatic characteristics and water shortages in the country, as well as the development plan for the cultivation of this plant due to its high nutritional value, attention to its water requirement becomes more important. For this reason, the importance of precise irrigation design and planning is needed in order to improve the performance of irrigation water usage in this region.Materials and MethodsThis research is conducted aim to determine the effects of different levels of moisture and salinity on the yield, some morphological traits, and some yield components of quinoa (Chenopodium quinoa Willd.) in field conditions during two growing seasons (2020-2022) in Yazd, Iran. The experiments were carried out in a factorial experiment in a randomized complete block design, which included two irrigation water salinity levels of 5 and 12 dS/m and four irrigation levels of 60, 80, 100, and 120% to provide the amount of allowable moisture depletion (MAD equal to 50%) in the root zone, in three replications. Experimental plots were designed with dimensions of 5×7 meters. Applying the amount of irrigation was done according to the determination of the field capacity levels and the permanent wilting point moisture measured (using a pressure plate device) before the start of the experiments. In this regard, according to this information, on the day of irrigation, the amount of soil moisture in each of the plots was measured at the root zone, and based on the treatments, the amount of water required was calculated, and irrigation was applied to the determined moisture level. Irrigation was carried out in the form of flooding, and the volume of irrigation water for each treatment was controlled by the volume contour and applied separately at each interval. At the end of the experiment, quinoa was harvested in a one-square-meter grid, and then plant height, panicle length and width, and stem diameter were measured. After the plant's drying, the weight of the seeds and the weight of the whole shoot were measured in different treatments.Results and DiscussionThe results showed that the different levels of salinity and soil moisture cause significant changes in biomass yield, seed yield, and harvest index. Also, the results indicated that changes in salinity levels and moisture levels caused significant differences in plant height, stem diameter and panicle length, panicle width, and 1000-seed weight (P<0.01), but their interaction was not significant. For two levels of salinity, the maximum biomass (9.28 tons/ha) was observed by supplying 100% of the depleted soil moisture based on MAD = 50%. According to the yield-water use function, the maximum seed yield for 5 and 12 dS/m irrigation water salinity was observed in treatments that supplied 115% and more than 120% of depleted soil moisture based on MAD = 50%, respectively. With the increase in salinity stress from 5 to 12 dS/m, biomass weight decreased by 23% and seed yield decreased by 17%. Based on the results, the average volume of applied water in fall cultivated quinoa under the 5 dS/m irrigation water salinity was 4900 m3/ha during the growth season (90 days).ConclusionIn the autumn planting of the Titicaca variety of quinoa, with a planting period of about 90 days in arid and semi-arid regions like Yazd, water consumption is about 450 to 550 mm. But in conditions of moisture deficiency, it is possible to grow this plant. Because it has a lower yield reduction slope than other plants under drought and salt stress conditions. Furthermore, the results indicated that the salinity of the soil profile increased in deficit irrigation conditions (60% and 80% of depleted soil moisture based on MAD = 50%) due to the lack of leaching requirements.
Volume 44 - Issue 1
Land Evaluation and Suitability
Behnam Kamkar; Parysa Alizadeh Dehkordi; Pooya Aalaee Bazkiaee; Omid Abdi
Abstract
Introduction: Understanding the suitability of the lands is very important in terms of the ability to cultivation a particular crop. Having information in this field helps us to act more intelligently in prioritizing land allocation for the cultivation of various crops. Also, adapting the current-grown ...
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Introduction: Understanding the suitability of the lands is very important in terms of the ability to cultivation a particular crop. Having information in this field helps us to act more intelligently in prioritizing land allocation for the cultivation of various crops. Also, adapting the current-grown lands under cultivation of a crop selected by the farmer to the final layer of land suitability can give us an overview of the right or wrong choice of land use. This information will help agricultural policymakers to replace crops when necessary and to replace crops that have been misallocated in disproportionately desirable lands with other crops or to improve their crop management. Therefore, this study was conducted to assess the land suitability of Golestan province agricultural lands for soybean cultivation and the degree of adaptation of current soybean-grown fields to the obtained suitability layers.Materials and Methods: This study was carried out in the agricultural lands of Golestan province with an area of 821 thousand hectares. First, the real lands under cultivation of soybean were separated using 1674 land samples taken from different crops and object-based image analysis (OBIA) method. To separate the lands under soybean cultivation in Golestan province, sentinel 2 satellite images with a spatial accuracy of 10 meters related to planting to harvesting time in 2018 were used. Then, the layers of soil, climate, and topography characteristics were provided to investigate land suitability for soybean cultivation. Climatic components including minimum, optimum, maximum temperatures, and rainfall were estimated using long-term statistics of synoptic stations in the province (maximum available statistics). Data of soil texture, nitrogen, organic matter, phosphorus and potassium, soil pH, and salinity were also received from the provincial agricultural and natural resources research center, and from the data, the soil properties map was obtained. The digital land elevation map (DEM) of the province with a spatial resolution of 20 meters was used to extract slope, elevation, and aspect maps. The process of interpolation of climatic and soil layers was performed using ordinary kriging method. The relative importance of each factor was determined through the Analytic Hierarchy Process (AHP). This was done by designing questionnaires based on AHP paired matrices and completing it by agricultural specialists. After extracting the weights from the questionnaires and preparing the classified raster layers, these layers were imported in GIS version 10.3. Combining and overlaying the layers was done by assigning AHP weight to each layer. Finally, a land suitability map was prepared for the cultivation of the soybean in the study area which, in turn, was used to determine the adaptation of current soybean fields with determined suitability classes.Results and Discussion: The accuracy of classification by object-oriented method using kappa coefficient and overall Accuracy coefficient (0.87 and 90%, respectively) shows the acceptable accuracy of soybean land separation in this study. In the study of land suitability for soybean cultivation, the results obtained from hierarchical analysis showed that the soil criterion had the greatest effect on the site selection of soybean cultivation with a coefficient of 0.52 with respect to both climate and topography factors. The results showed that most of the fields (about 87% of total) placed in suitable class and 13% placed in a relatively suitable class. In suitable areas for cultivation, despite having the best conditions for factors such as maximum temperature, average temperature, slope, aspect, height, soil texture, soil pH, phosphorus and soil salinity, soybean production is limited by factors such as precipitation (400 to 500 mm per year), minimum temperature (10 to 12 °C), phosphorus (8 to 10, 15 to 20 mg/kg soil). In these areas, maximum yield can be achieved by managing the mentioned factors and applying desirable agricultural management. In relatively suitable areas, limitations of nitrogen deficiency (less than 0.5 mg/kg soil), organic matter (less than 2%), salinity (above 6 dS/m), slope (more than 5%), restriction of soybean cultivation due to heavy soil texture (high percentage of soil clay), potassium (less than 100 mg/kg soil), phosphorus (more than 20 or less than 8 mg/kg soil), precipitation (less than 400 mm per year), minimum temperature (less than 10 °C), slope (more than 8%) and aspect (west and north) caused relatively high land restrictions for soybean cultivation. Compatibility analysis of the current soybean fields with the suitability maps indicated that about 99% of total cultivated lands are located in a suitable class, which demonstrates the proper selection of farm locations by the farmers. Conclusion: By considering the position of Golestan province in the production and area under soybean cultivation in the country, if it is possible to identify suitable soybean cultivation areas according to the environmental requirements of this product and identify the limitations created by the environment, more yield per area can be achieved, which will improve the agricultural economy and the level of income of the country.
Volume 46 - Issue 3
Soil Chemistry and Pollution
Zahra Albozahar; Neda Moradi; ُSaeid Hojati
Abstract
Introduction: Today, water consumption has increased dramatically as a result of technological advancement, extraordinary industrial development and urbanization, which has caused the production of large amounts of toxic waste. Zinc (Zn) is an essential element for plants and humans, however, excessive ...
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Introduction: Today, water consumption has increased dramatically as a result of technological advancement, extraordinary industrial development and urbanization, which has caused the production of large amounts of toxic waste. Zinc (Zn) is an essential element for plants and humans, however, excessive concentrations of zinc can cause problems for humans such as abdominal pain, nausea and vomiting. Zinc is the most toxic pollutant that enters the aquatic system through industrial wastewater. World health organization (WHO) has recommended limit concentration of zinc in drinking water of 5.0 mg L-1. Adsorption is one of the most efficient ways to remove heavy metals from the environment. Clay minerals are one of the good adsorbents for the adsorption of heavy metals due to their large surface areas, high ion exchange capacity and layered structure. Some factors such as temperature, pH, size of adsorbent, type of adsorbent and amount of adsorbent are considered as important factors in controlling the behavior of heavy metals in aqueous solution. The temperature of the solution can increase or decrease the adsorption of elements, which indicates the exothermic or exothermic nature of the surface adsorption reaction. Therefore, this research was carried out with the aim of investigating the effect of temperature on the kinetics and thermodynamics of Zn removal using sepiolite and kaolinite minerals.Materials and Methods: In this research, two clay minerals (kaolinite and sepiolite) in a size of 25-53 µm were used as zinc metal adsorbents. Sepiolite mineral was collected from mines in Fariman region of Razavi Khorasan province and kaolinite was collected from Lalejin in Hamadan province. The kinetics and thermodynamics of Zn absorption from aqueous solutions by sepiolite and kaolinite were investigated. For kinetic studies, 0.1 g of sepiolite and kaolinite adsorbent was poured into a centrifuge tube and 20 ml of Zn solution with a concentration of 50 mg L-1 of zinc nitrate background solution was added to it and at different times (5, 10, 15, 20, 30, 60, 120, 240, 480, 720, 1440 and 2880 minutes) was stirred. The experiment of adsorption kinetics was performed at pH 5 and at a temperature of 25 ± 1 °C. The thermodynamics of zinc adsorption was investigated at temperatures of 25, 35 and 45 ℃. The adsorption behavior of zinc metal by sepiolite and kaolinite minerals was evaluated at different times with pseudo-first-order, pseudo-second-order, Ilovich and intraparticle diffusion kinetic models through non-linear regression and using Solver software. Then, the thermodynamic parameters of adsorption process including: the activation energy (Ea), gibbs free energy (ΔG), entropy (ΔS) and enthalpy (ΔH) were determined.Results and Discussion: The results of this research showed that by increasing the contact time and decreasing the temperature of the solution from 45 to 25 ℃, the amount of Zn adsorption by both minerals increased. Also, the equilibrium time was determined to be 720 minutes. The results showed that the adsorption efficiency decreases with increasing temperature and the highest removal percentage was observed at 25 ℃. Based on the results obtained from the fitting of kinetic models with experimental data, the pseudo-second order model with the highest explanatory coefficient (R2=0.99) was selected as the best model. Adsorption capacity (qe) of Zn estimated from the pseudo-second order model for sepiolite and kaolinite at 25℃ compared to 45℃ decreased by 44.30 and 38.19%, respectively. Also, the amount of Zn adsorption capacity for sepiolite mineral was higher than kaolinite. The activation energy (-9.79 to -23.81 kJ mol-1) revealed the physical adsorption of Zn by sepiolite and kaolinite. The activation energy of Zn adsorption onto the sepiolite (-23.81 kJ mol-1) and Kaolinite (-9.79 kJ mol-1) indicated that Zn was more strongly sorbed by sepiolite than kaolinite. Conclusion: the results obtained showed that sepiolite and kaolinite can be used an adsorbed to remove Zn from aqueous solution with good efficiency and low cost, while sepiolite had higher Zn adsorption capacity compared to kaolinite. Adsorption of Zn decreased with increasing temperature. The optimal temperature in this study for maximum adsorption of Zn by sepiolite and kaolinite was 40℃. Thermodynamic parameters including changes in Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) showed that zinc adsorption process by the studied minerals is an exothermic and spontaneous reaction. As a conclusion, sepiolite has a high potential for remove of Zn from wastewater.
Volume 43 - Issue 2
Negar Hafezi; Mohammad Javad SheikhDavoodi; Houshang Bahrami; Seyed Enayatallah Alavi
Abstract
Introduction Sugarcane is a tropical, perennial grass that forms lateral shoots at the base to produce multiple stems. It is the main source of sugar production and one of the most important sources of energy production in the world. Today, the use of artificial intelligence and data mining findings ...
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Introduction Sugarcane is a tropical, perennial grass that forms lateral shoots at the base to produce multiple stems. It is the main source of sugar production and one of the most important sources of energy production in the world. Today, the use of artificial intelligence and data mining findings to help predict product production is considered. Determining the relationship between inputs and outputs of production process using artificial intelligence (AI) has drawn more attention rather than mathematical models to find the relationships between input and output variables by training, and producing results without any prior assumptions. The adaptive neuro-fuzzy inference system (ANFIS), as a form of AI, is a combination of artificial neural network (ANN) and fuzzy systems that uses the learning capability of the ANN to derive the fuzzy if-then rules with appropriate membership functions worked out from the training pairs, which in turn leads to the inference.Particle swarm optimization (PSO) is an algorithm modeled on swarm intelligence, in a search space, or model it finds a solution to an optimization problem and predict social behavior in the presence of objectives. The PSO is a population-based stochastic computer algorithm, modeled on swarm intelligence. Swarm intelligence is based on social psychological principles and it provides insights into social behavior, also helps to many engineering applications. Feature selection is becoming very important in predictive analytics. Indeed, many data sets contain a large number of features, so we have to select the most useful ones. One of the most advanced methods to do that is the genetic algorithm (GA). Genetic algorithms can select the best subset of variables for predictive model. The purpose of this research is to evaluate the applicability of one artificial intelligence technique including adaptive neuro-fuzzy inference system and also combining this technique with particle swarm optimization to increase the accuracy and speed of training of the neuro-fuzzy system in prediction of yield and recoverable sugar percentage (R.S%) of sugarcane. Materials and Methods In this paper, one main pattern of adaptive neuro-fuzzy inference system (ANFIS) and one synthetic model of adaptive neuro-fuzzy inference system with particle swarm optimization (PSO) were used to predict the studied properties by MATLAB version 2017. Initial data for this study were collected from Debal-Khozaie Agro-industry Company in Khouzestan province, Iran. The actual data for the seven periods of sugarcane harvest from 2010 to 2017 were used for modeling. The studied parameters included a set of agronomic factors, soil characteristics, irrigation and climate in the study area. The test data sets were used for comparison of selected ANFIS and ANFIS with PSO, as well as for the observation values. This comparison was performed by using three statistical indices: Determination Coefficient (R2), Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE). Results and DiscussionFrom all of the studied parameters, eleven parameters were selected as the effective features by the binary genetic algorithm (BGA). In feature selection, the function to optimize is the generalization performance of a predictive model. More specifically, in this method, purpose was to minimize the error of the model on an independent data set not used to create the model. The data were randomly divided into two groups: training and testing. Each pattern was modeled separately and then the results were compared. The results showed that the combination of adaptive neuro-fuzzy inference system with particle swarm optimization algorithm (ANFIS-PSO) had better performance in predicting cane yield and recoverable sugar percentage. In ANFIS-PSO model the root mean square error, mean absolute percentage error and coefficient of determination values were found 0.0181, 0.0217, 0.9237 and 0.0086, 0.0138, 0.9847 respectively for two variables of cane yield and recoverable sugar percentage. In relation to the predicted cane yield by the neuro-fuzzy network with particle swarm algorithm, it can be concluded that among the effective factors, with increasing plant age and use of resistant varieties, the amount of yield was decreased and increased, respectively. Conclusion The hybrid pattern of adaptive neuro-fuzzy inference system with the particle swarm optimization has been directed against the mere neuro-fuzzy system to a more accurate and stronger solution. Indeed, it can be concluded that ANFIS model with the PSO has the ability for precise estimation of sugarcane yield and recoverable sugar percentage.
Volume 44 - Issue 2
Zahra Rezaee; Mojtaba Norouzi masir; Abdolamir Moezzi
Abstract
Introduction:Organic matter based on their composition and the C/N ratio can have different effects on nutrient bioavailability, concentration and uptake in soil and plant. Beside that, organic fertilizer can increase the yield of different agricultural products and pave the wey for emergence of sustainable ...
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Introduction:Organic matter based on their composition and the C/N ratio can have different effects on nutrient bioavailability, concentration and uptake in soil and plant. Beside that, organic fertilizer can increase the yield of different agricultural products and pave the wey for emergence of sustainable agricultural . Organic matter is relatively low in majority of soils in Iran, and continuous use of chemical fertilizer would create environmental hazards . Zinc deficiency is a worldwide nutritional constraint in crop production particularly in cereals growing on calcareous soils .Materials and methods:This research was conducted to investigate the effects of organic fertilizers such as bagasse, compost and biochar and chemical fertilizer ZnSo4 on yield of wheat and concentration and uptake of Zn in wheat ,a study based on randomized complete block design with 3 replications was conducted in Greenhouse Faculty of Agriculturar of Shahid Chamran University of Ahvaz during the years1395-96. Treatments included:1-control ,2- ZnSo4 , 3-Bagasse 4- Biochar 5- compost. Some Physical and chemical properties were determined using standard methods (table1).some basic properties of bagasse , compost and biochar were also determined (table 2). after the experiment ,soil and plant properties such as pH, organic matter content(OM), available Zn in soil. and yield , yield components and concentration and uptake of Zn in wheat were determined in samples.After seed ripening grain , yield and component yield were measured from the total pot of each treatment.Statisical analysis of the data was performed using SAS software and comporision using Toki method was also performed.Results: the intial soil was clay loam with organic matter content( om=0.79).Results showed that the treatments had significant effect (p≤ 0.01) on percentage of organic carbon, organic matter, the availability of Zn and pH of soil . Also content of soil micro element affected by treatments and amount of these parameters were increased by using of organic fertilizers .Increase the organic matter in soil by compost improved a must of chemical peroperties and Increase concentration nutrient element in soil. Results showed that pH in the control decreased significantly from 7.74 of soil to 7.53 of soil in the compost. Results showed that the available Zn in the control increased significantly from 0.5 mg kg-1 of soil to 0.71 mg kg-1 of soil in the compost.The results of the experiment showed that all treatments except bagsse increased factors wheat yield . Compost showed greatest yield and bagasse the lowest yield in the the wheat root, grain and shoots (compared to the control). The highest grain yield was obtained from the application of compost. The maximum amount of chlorophylls (a, b, total and SPAD), with application compost. The highest Plant height was obtained from the application of biochar. The results showed that the highest and the lowest of va lue concentration and uptake of Zn in wheat to compos and bagasse respectivity. The maximum amount of chlorophylls (a, b, total and SPAD), with application compost. The highest Plant height was obtained from the application of biochar. The results showed that the highest and the lowest of va lue concentration and uptake of Zn in wheat to compos and bagasse respectivity. Discussion:The obtained result highlight the increased effects of compost on yield and yield components and Zn uptake change in wheat, also in comparison to other treatments, it emphasizes ore on the soil though they were useful too. Therefore, it can be concluded that applying organic fertilizers especially composted form would have, useful effects on plant growth and increasing the concentration of Zn of wheat .The obtained result highlight the increased effects of compost on yield and yield components and Zn uptake change in wheat, also in comparison to other treatments, it emphasizes ore on the soil though they were useful too. Therefore, it can be concluded that applying organic fertilizers especially composted form would have, useful effects on plant growth and increasing the concentration of Zn of wheat .The obtained result highlight the increased effects of compost on yield and yield components and Zn uptake change in wheat, also in comparison to other treatments, it emphasizes ore on the soil though they were useful too. Therefore, it can be concluded that applying organic fertilizers especially composted form would have, useful effects on plant growth and increasing the concentration of Zn of wheat .
Volume 43 - Issue 3
Alireza Zahirnia; H. Matinfar; Hossinali Bahrami
Abstract
Low rainfall, lack of irrigation water of good quality, high water level and high annual evaporation in the southwestern region of Khuzestan, has led to the emergence of saline soils. Various environmental factors, such as low production of soil organic matter, high salt content, high concentration of ...
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Low rainfall, lack of irrigation water of good quality, high water level and high annual evaporation in the southwestern region of Khuzestan, has led to the emergence of saline soils. Various environmental factors, such as low production of soil organic matter, high salt content, high concentration of sodium ions, high pH and quality and depth of groundwater, have significant effects on the qualitative indicators of saline soils in arid and semi-arid regions. Soil quality indicates the ability of the soil to provide biological services to living organisms. These services include food production, water treatment, pollution absorption, carbon dioxide absorption, and the production of a variety of medicinal and industrial plants. Soil quality is an important indicator of agricultural and environmental sustainability and is used to assess soil quality. Each soil quality index must have biological characteristics, be sensitive to environmental and managerial changes, and be effective in measuring measurable and quantitative processing. The present study was conducted to determine the soil quality index in a part of the southwestern lands of Khuzestan province with three land use of agriculture and industry, traditional agriculture and barren lands in a part of the southwestern region of Khuzestan province. In this study, using systematic networking method as well as the characteristics of the study area, a total of 180 soil samples were selected and 22 physical, chemical and biological parameters were determined in each sample. The parameters studied in this study were: electrical conductivity, pH, ions such as sodium, calcium, magnesium, chlorine, bicarbonate, sulfate, SAR, CEC, exchangeable potassium, ozone-absorbable phosphorus, percentage of organic matter, activated carbon, Percentage of clay, silt and sand, average soil diameter, water permeability coefficient in saturated state, specific apparent weight and surface soil hardness. After the laboratory results were determined, using statistical method of factor analysis (FA) and principal component analysis (PCA) in SPSS statistical software, among all the characteristics affecting soil quality (TDS), five characteristics of electrical conductivity, sodium concentration, Chlorine, sulfate, and SAR were identified as the most important characteristics affecting soil quality (MDS). The selection of these factors as MDS indicates the high impact of soluble salts and the low depth of ground water on soil quality indicators of the study area, so that the accumulation of salts on the surface and depth of soil, mainly affects soil quality. To evaluate the lands, two models of cumulative soil quality index (IQI) and Nemro quality index (NQI) were used in two sets of MDS and TDS. Then, in order to compare the performance of soil quality index methods, common methods of secondary root and maximum limitation were used. The results showed that in general, the lands of the region were at different levels in terms of soil quality indicators and land suitability assessment methods, so that the lands of cultivation and industry showed maximum quality, lands under traditional cultivation with medium quality and barren lands showed minimum quality. The Kappa coefficient calculated between the Cumulative Soil Quality Index (IQITDS) and the second and maximum rootstock methods was 0.83 and 0.37, respectively, indicating a high and moderate level of coordination between the data obtained from the various methods tested. The calculated correlation between the results obtained from IQITDS and IQIMDS is equal to 88.43% and also between the results of NQITDS and NQIMDS is equal to 80.59%, which are statistically significant. This suggests that a well-prepared MDS set can be used to represent the TDS set. Therefore, MDS can be used instead of TDS to reduce the time and cost of implementing similar research projects. The results of this study show that soil leaching and leaching of salts from the surface and depth of soil profiles, especially in barren lands and under traditional agriculture has been observed and this is the main cause of differences between these lands and lands under agricultural management and industry. In cultivation and industrial lands, due to leveling, drainage and leaching, additional salts have been washed from the soil profile as much as possible and the conditions for plant growth have been provided. It seems continuity of agricultural and industrial land management, especially in the field of adding low-consumption elements, organic matter and improving physical properties, should be done in such a way that soil quality indicators are closer to the optimal range.
Volume 44 - Issue 4
A.R. Fallah Nosratabad; Sh, Shariati
Abstract
Introduction Phosphorus (P) is one of the most necessary plant nutrients and the second key plant nutrient after nitrogen, which deeply affects the overall growth of plants. Most of the present P in calcareous soils is biologically unavailable, therefore mobile P is rare despite the abundance of both ...
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Introduction Phosphorus (P) is one of the most necessary plant nutrients and the second key plant nutrient after nitrogen, which deeply affects the overall growth of plants. Most of the present P in calcareous soils is biologically unavailable, therefore mobile P is rare despite the abundance of both organic and inorganic forms of P in soils. It has been well-known that P use efficiency of triple superphosphate (TSP) fertilizer in alkaline soils is low. Due to the increase in the price of phosphate fertilizers and their low plant absorption (10–30%), the use of indigenous phosphate solubilizing bacteria (PSB) to increase P-fertilizer-use efficiency and reduce its application amount can be a perfect way. The combined use of bio-fertilizers and superphosphate is an important component of integrated nutrient management, which leads to sustainable agriculture. This research was carried out to investigate the contribution of native phosphate solubilizing Pseudomonas sp. along with superphosphate application to increase soil P solubility, yield and nutrient concentration of maize and improve some soil properties in a calcareous soil with low organic matter and phosphorus.Materials and Methods Eleven strains of Pseudomonas sp (Pseudomonas sp. Pseudomonas koreensis) bacteria were obtained from the Gene Bank of Iran Soil and Water Research Institute. The phosphate solubilizing activity of each bacterium was evaluated in Sperber medium quantitatively (liquid) and qualitatively (plates). Each bacterium was cultured in two plates with three replications and incubated at 28 °C. Then the colony and halo diameter were measured on the third, fifth, seventh, tenth, and fourteenth days after incubation. To evaluate phosphate solubility by bacteria in a liquid medium, 50 ml of Sperber medium was prepared and sterilized with three replications. Then 1 ml of fresh culture suspension of each bacterium with a population of 107 cells/ml was inoculated into each Erlenmeyer flask (treatments and controls) and incubated at 150 rpm and 150 ° C for 14 days. Soluble phosphorus (Vanadate-molybdate method) and pH on the first, third, tenth and fourteenth days of incubation were measured. To assay the interaction effects of bacteria and triple superphosphate fertilizer on quantitative and qualitative yield of maize plant and characteristics of soil cultivated in a soil with low level of organic matter and phosphorous, a factorial based on randomized completely design including 8 bacteria (B0, B1, B2, B3, B4, B5, B6, B7) and 4 triple superphosphate fertilizer levels (0, 40, 70 and 100% of the critical limit of soil phosphorus) with 3 replications was conducted in greenhouse conditions. Sterilized pots containing 7 kg of washed sands and soil (in a ratio of one to three) were prepared. A certain amount of triple superphosphate fertilizer was added to each pot based on the treatments. The K as potassium sulfate and N as urea were used based on soil test and fertilizer recommendations for maize. Five germinated seeds (704 single cross cultivar) were planted in each pot. Seeds sown were inoculated with 1 ml of the fresh bacterial suspension inoculum (1×108 CFU ml-1). Then after two weeks, three plants per pot were preserved and the rest were removed. Pots including different treatments were irrigated, up to 80% moisture content of field capacity (FC), by distilled water using a weight method. After 90 days, the dry weight of the plant was calculated (oven at 70 ° C for 48 hours). To analyze the nutrients in the plant, roots and shoots were powdered separately by mill and digested through dry burning method. The amount of phosphorus, potassium, nitrogen, iron, zinc, copper and manganese were measured in shoot and root of the plants. Besides, the soil of each pot was sampled and after air drying and passing through a 2 mm sieve, some characteristics of the cultivated soil such as pH, EC, P (ava), TNV, Fe, Mn, Cu, Zn were measured and compared with the initial soil properties (before planting). Data statistical analysis was performed using SAS software and the mean comparison of treatment was carried out using Duncan's method. Results and Discussion: The results of phosphorus solubilizing bacteria effect on the dissolution of insoluble mineral phosphates in solid and liquid media showed the largest halo diameter (19.11 mm) and the highest dissolution of P (156.25% compared to the control) after the fourteenth day incubation was belong to strain P21-1 and strain P55-1, respectively and a decrease in pH (45.5- 47.3 %). The results of the mean comparison showed that P0B3 treatment could increase the shoot dry weight by 47.45 %. P40B1 treatment was able to increase 61.62% of root dry weight. P70B6 and B70B2 treatments were also able to increase P in shoots by 17.64%, P100B4 treatment could increase root phosphorus by 160%. Besides, the combined use of bio-fertilizer and superphosphate increased the elements of iron, zinc, manganese, P, and reduced the electrical conductivity of the soil.Conclusion All strains used in this study were able to dissolve phosphorus in both liquid and solid media. The results showed that the co-application of biofertilizer and phosphorus fertilizer increased the growth of maize plant (shoot and root dry weight) and shoot and root phosphorus concentration compared to the control. In addition, the use of these treatments increased the available phosphorus, iron and zinc in soil and decreased the electrical conductivity of the soil. Therefore, the findings of this study indicate that the use of inoculants containing Pseudomonas sp. and Pseudomonas koreensis can be considered as a suitable supplement to triple superphosphate fertilizer in crop cultivation strategies.
Volume 43 - Issue 4
Saeed Mohamadi; Nafiseh Rang Zan; Habibollah Nadian Ghomsheh
Abstract
Introduction Due to the inefficiency of some chemical fertilizers of trace elements, the high cost of import organic fertilizers containing these elements and also the lack of proper uptake of phosphorus in soils in arid and semi-arid regions, and the desire to produce better quality products, the use ...
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Introduction Due to the inefficiency of some chemical fertilizers of trace elements, the high cost of import organic fertilizers containing these elements and also the lack of proper uptake of phosphorus in soils in arid and semi-arid regions, and the desire to produce better quality products, the use of organic matter enriched with nutrients such as phosphorus and iron seems essential. Therefore, the present study was conducted with the aim of comparing the effect of different levels of iron refuse and phosphate soil as an enrichment and investigating the interaction effects of enrichment on the growth components of tomato plants.Materials and Methods To study the effect of compost enriched with iron refuse and phosphate soil on tomato plant, pot experimen was conducted with experimental treatments including compost enriched with iron refuse at three levels of 0, 5 and 20%, compost enriched with phosphate soil at three levels 0, 5% and 10%. To prepare the potting soil before applying the treatments, 10% by weight of sand was added to the soil. Iron refuse were prepared from the factory of National Iranian Steel Industrial Group and phosphate soil from Esfordi phosphate company and after air drying, the percentage of iron and total phosphorus were measured using standard methods (wet digestion). Compost prepared from green space wastes was also digest to investigate some chemical properties. Obtained data were performed analysed in factoriall in completely randomized design with three replications. Statistical analysis was performed using SPSS software and mean comparisons were performed by Duncan's multiple range test. Charts were drawn using Excel software.Results and Discussion The results showed the highest plant height was observed in the treatment of 20% iron enrichment with 10% phosphorus enrichment at the rate of 57.9 cm. Comparisons of the mean effect of iron enrichment on total chlorophyll in tomato leaves showed that in general, with increasing the percentage of iron, total chlorophyll increased by 17.6 and 18.2%, respectively, compared to the control treatment. In other words, enrichment of compost with iron refuse increases the plant chlorophyll content by 39%, which is 34% for phosphorus enrichment. The maximum chlorophyll content of the plant was observed in the treatment of 20% iron enrichment with 10% phosphorus, which was not significantly different from the 20% iron enrichment treatment and 5% phosphorus enrichment treatment. Therefore, simultaneous enrichment of compost with iron and phosphorus can increase the quality of crops, especially leafy vegetables. According to the results, increasing the level of iron enrichment from zero to 20% caused 42.4% increase in plant dry weight, which is reported to be 24.9% for phosphorus enrichment. In general, as expected, with increasing the percentage of phosphorus in compost, the concentration of phosphorus in the shoot of tomato plant increased. Iron concentration in the plant increases by 10.9% with increasing phosphorus enrichment level from zero to 5%; In contrast, the use of phosphate soil at the level of 5% caused a decrease in zinc and copper concentrations of the plant by 21.5% and 15.2%, respectively. In many cases, the phosphorus and iron have reducing effects on each other due to the deposition of soluble iron in the form of insoluble phosphate compounds. According to the results of the present study, when an organic medium such as compost is used to add these two elements to the soil, the effect of organic matter on the formation of soluble chelates can increase the amount of avalable iron. Organic matter also has an undeniable effect on preventing the stabilization of phosphorus, which causes its release due to the direct decomposition of organic matter or the production of organic acids. Cupper was found to be more sensitive to increasing the amount of phosphorus in soil.Conclusion The use of enriching compounds by improving plant nutritional conditions can lead to improve effects of organic amendments such as compost. The use of phosphate-enriched compost and iron refuse, increased the yield of tomato plants. According to the results, high levels of enrichment to some extent limit the uptake of zinc and copper, which is related to the interaction of elements with each other and changes in concentration ratios. Due to the lack of micronutrients in most crops and horticulture and the competition of elements in the soil, in many cases there is a decline in product quality, so it is suggested that following the present study, some studies to be conducted to investigate the simultaneous enrichment of other micronutrients such as zinc and copper and balance dose of enrichment so that maximum absorption is achieved simultaneously for all target elements. The use of waste from different sources to balance the enrichment of organic materials, in addition to reducing costs, will lead to the recycling of large volumes of waste.
Volume 35 - Issue 1
A. Rohani; S. Zarifneshat; M.H. Abbaspour Fard
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 36 - Issue 1
Abolfazl Hedayatipour; Mohammad Lak; Marefat Mostafavi Rad
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 87-99
Abstract
In order to evaluate the effects of type of herbicide and tillage implements on weeds control, seed yield and some agronomic traits ofbean (Phaseolous vulgaris L.), two field experiments were carried out as factorial arrangement in complete block design with three replications during 2007 and 2008 growing ...
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In order to evaluate the effects of type of herbicide and tillage implements on weeds control, seed yield and some agronomic traits ofbean (Phaseolous vulgaris L.), two field experiments were carried out as factorial arrangement in complete block design with three replications during 2007 and 2008 growing seasons at Khomain Research Station (49º 57´ N; 33º 39´ E, and 1930 m above sea level) in Agricultural and Natural Resources Research Center of Markazi Province. Two types of herbicides including Trifluralin and Ethalfluralin and three tillage implements such as rotary plow, disc and cultivator, comprised the experimental factors. Results of combined analysis showed that the effect of tillage implements and type of herbicide for seed yield and weed population were significant at 5% probability. In this research, application of Ethalfluralin and rotary plow had superiority for enhancement of seed yield and decrement of weeds population. In addition, tillage implements such as rotary plow and disc showed superiority for incorporation of soil and herbicide, respectively.
Volume 32 - Issue 1
A.R. Vaezi; H.A. Bahrami; S.H.R. Sadeghi; M.H. Mahdian
Volume 33 - Issue 2
Volume 36 - Issue 2
Negin Sohrabi; Hekmat Rabbani; Rashid Gholami
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 93-104
Abstract
Knowing physical and mechanical properties of the flowers is one of the important factors in designing, harvesting and post harvesting machines. A completely randomized design with factorial test was used in this research. Effect of shear speed, flower diameter, blade mode and shear angle on shear strength ...
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Knowing physical and mechanical properties of the flowers is one of the important factors in designing, harvesting and post harvesting machines. A completely randomized design with factorial test was used in this research. Effect of shear speed, flower diameter, blade mode and shear angle on shear strength and shear energy per stem area unit and effect of picking speed and petal diameter on petal and sepal on the tensile strength and energy consumed per unit of area were determined for Rosa damascena Mill. Shear strength was decreased by increasing shear angle from zero to 25 and 45 degree but it was not significant. Energy per unit of stem area and elastic modulus were decreased by increasing shear angle and it was significant at 5% probability level. Increasing shear speed from 150 to 250 mm/min was not significant on decreasing shear strength and elastic modulus but was significant at 5% probability level for 350 mm/min. Energy per unit of stem area was decreased by increasing shear speed. Shear strength, elastic modulus and shear energy per stem area unit were decreased by increasing flower diameter. Two treatments (Picking speed and flower diameter) were not significant on the tensile strength and picking energy per unit for both picking petal and sepal.
Volume 37 - Issue 1
Soil Biology, Biochemistry and Biotechnology
S. Shariati; H. Alikhani; A. Pourbabaei; F. Shariati
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 93-107
Abstract
In order to determine the effect of plant growth promoting bacteria Pseudomonas fluorescens on yield and nutrient availability in corn some special materials like mesoporous silica nanoparticles, vermicompost, bentonite and a mixture of all were inoculated by the bacteria and preserved for six months. ...
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In order to determine the effect of plant growth promoting bacteria Pseudomonas fluorescens on yield and nutrient availability in corn some special materials like mesoporous silica nanoparticles, vermicompost, bentonite and a mixture of all were inoculated by the bacteria and preserved for six months. Soil and seeds were treated by the inoculants. The experiment was set up in a randomized complete block design with three replications. The treatments comprised of three inoculants and two fertilizers including diammonium phosphate, single super phosphate and control (without any phosphorus fertilizer). After 60 days of corn emergence, some plant growth indices and the concentration of some elements in plant shoots were measured. The results demonstrated that Pseudomonas fluorescens inoculant significantly increased phosphorus shoot content, total yield and chlorophyll by 74, 46 and 22.1%, respectively compared to the control treatment (P<0.05), but it did not show any significant difference with phosphorus fertilizer treatments (P>0.05). The vermicompost inoculants could significantly (P<0.05) increase zinc and iron contents of shoots by 114 and 53.6%, respectively in comparison to the control treatment. Orthogonal comparisons of the two methods of seed and soil inoculation showed the efficiency of seed inoculation on shoot phosphorus at 5% level, but no significant difference was observed between these two methods for other measured characteristics (P>0.05).
Volume 35 - Issue 2
Akram Ahmadpoor Sefidkoohi; Mehdi Ghajar Sepanlou; Mohammad Bahmanyar
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 97-109
Abstract
In order to investigate the effects of applying three and five continuous periods of municipal solid waste (MSW) with and without NPK chemical fertilizer on the amount of micronutrient uptake by different parts of wheat, a pot experiment was conducted in split plot based on randomized complete block ...
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In order to investigate the effects of applying three and five continuous periods of municipal solid waste (MSW) with and without NPK chemical fertilizer on the amount of micronutrient uptake by different parts of wheat, a pot experiment was conducted in split plot based on randomized complete block design with four replications in 2009. The main plot was a six-fertilizers level including control (without MSW and chemical fertilizer), chemical fertilizers according to soil test (200 kg urea, 150 kg triple superphosphate, and 100 kg K2SO4 per ha) and 4 levels of MSW (20 and 40 ton.ha-1 without fertilizer and with half of fertilizer) and the sub plot was applying 3 and 5 continuous periods of MSW. The results showed that, by increasing the amount and periods of applying MSW, the concentration of Zn and Mn in flag leaf and straw of wheat increased, with the maximum amount of obtained with the application of five consecutive periods 40 ton MSW enriched with half of NPK fertilizer. Also, by increasing the amount of applying MSW, concentration of Fe increased in flag leaf. Dmoreoven, in wheat seed, the most amount of Zn, Fe and Mn was observed by applying 5 consecutive periods 40 ton MSW enriched with 1/2 fertilizer in soil. Meanwhile, by increasing the amount of applying MSW in soil, the concentration of Cu increased in flag leaf, straw and kernel wheat flag leaf, shoot and seeds, and the effects of periods of application of MSW was just showed in wheat seeds.
Volume 34 - Issue 2
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 97-105
Abstract
In the present research, the performance characteristics of a four-cylinder spark ignition engine were investigated using bioethanol – gasoline blends. The experiments were performed in factorial tests with a randomized complete block design with three replications. Factors of experiments were ...
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In the present research, the performance characteristics of a four-cylinder spark ignition engine were investigated using bioethanol – gasoline blends. The experiments were performed in factorial tests with a randomized complete block design with three replications. Factors of experiments were six bioethanol- gasoline blends (E0, E10, E20, E30, E40 and E50) and six engine speeds (2000, 2500. 3000, 3500, 4000 and 4500 rpm). Engine performance characteristics for fuel blends were compared with gasoline. The results of the engine test showed that bioethanol addition to gasoline significantly increased the torque, brake power, and brake thermal efficiency while the brake specific fuel consumption decreased in E10 and increased in E50. Results showed that in all engine speeds, 10 vol.% ethanol in fuel blend gave the best results for torque, brake power and brake specific fuel consumption.
Volume 41 - Issue 3
Post Harvesting Technology
Armin Ziaratban; M Azadbakht; Azim Ghasemnezhad
Abstract
Background and objective Unlike engineering materials, apples are living tissues which survive after harvesting. Thus, post-harvest processes such as transporting and packaging should be carried out in a way that makes them less vulnerable. Among the agricultural products, fruits and vegetables are the ...
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Background and objective Unlike engineering materials, apples are living tissues which survive after harvesting. Thus, post-harvest processes such as transporting and packaging should be carried out in a way that makes them less vulnerable. Among the agricultural products, fruits and vegetables are the commodities that due to their low resistance to the shell and high humidity, have a high sensitivity against mechanical damages that occur when processing them. In order to minimize waste, proper post-harvest management and convenient techniques for transport and storage are required. Mechanical damages can occur in three major ways, including pressure, impact, and abrasion. The pressure during the harvest may impose on the fruits by pickers or occur when fruits are stored in the bottom of the box. External damages may happen due to the weight of picked apples in the baskets in deep boxes or when transporting the boxes by hooks. In fruit packaging stations, pressure, impact, and vibration can occur when packaging of fruits in boxes, as well as the washing and waxing fruits. Pressure forces usually happen during transport and storage of the fruit. This study was undertaken to study the impact on sugar, phenol, acidity and fatigue area that play a major role in the final quality of the product. Materials and methods Static and dynamic impacts and storage time were considered as the independent factors in this study and their effects were analyzed on the chemical parameters including sugar, phenol, acidity and fatigue area. The static impact was conducted by Instron Sntam with three loading speed 5, 7, and 10 mm/min for 1min. The dynamic impact was conducted by a pendulum that simulated the energy applied to apples that dropped. The amount of energy was equivalent to 2.25, 3 and 3.75 J. Apples that underwent impacts, were kept for 20, 40 and 60 days to measure the impact on changes of chemical parameters and determine the area of fatigue. After each storage period, the samples were photographed. The area of fatigue was measured using image processing techniques and Image J software. The image processing consists of two parts: hardware and software. The hardware of computers, cameras and imaging chamber is formed. The camera was connected by cable to a computer and the images were stored on a computer's permanent memory. Used computers used running windows seven, five-core central processing unit, and RAM was 4 Giga bytes. Computer is the processing of the data and the image acquisition step to the final step, the output data is the most important role. The used camera was a Canon, made in Japan, was mounted vertically inside the box. Shooting box was used just because all the photos must be taken in a constant condition of light regarding light intensity of surroundings and distance of apples from the camera. The Chamber was made of wood and shaped like a cube with dimensions of 45 × 45 × 45 cm, which is just an open area. Three eight-watt fluorescent lamps for lighting inside the box was fixed to the ceiling box around the triangle mounted camera. Image J analyzer is a powerful software with various uses. This software can calculate the area and pixel value statistics of user-selected portions of the image. Factorial experiments were carried out in a completely randomized design with three replications. Results Results revealed that acidity changes and fatigue area during the storage under static and dynamic impacts were significant at 0.01 and 0.05% and for phenol and sugar were significant at 1 and 5%. Also, in this test, sugar content and acidity were generally reduced over time, and phenol and fatigue area increased. Conclusion In order to avoid excessive reduction in sugar and fruit quality, maintenance time should be reduced as much as possible. Phenol increased during storage, after applying impact; its oxidation when contacting air results in toxic compounds that are harmful to humans. Therefore, packaging using the pads and increasing the quality of the harvesting and transporting is necessary in order to reduce the damages to the fruit. Fruit acidity during storage after the impacts showed the significant changes that could negatively affect the taste of the fruit and as a result, its marketability.
Volume 41 - Issue 2
Soil Genesis and Classification
Mehdi Taheri
Abstract
Introduction During the last decade, considerable progress has been made in the study of known loess deposits and their paleoclimatic implications in Northern Iran, whereas little information is available about the red soils which are beneath the these loess. So, in this study, major and trace element ...
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Introduction During the last decade, considerable progress has been made in the study of known loess deposits and their paleoclimatic implications in Northern Iran, whereas little information is available about the red soils which are beneath the these loess. So, in this study, major and trace element concentrations were analyzed on the samples from a red sequence of Iranian Loess Plateau at Golestan province. The main objectives of this research are a) to address the origin of the red soils with compare to the other geochemical results such as upper Pleistocene loess-paleosol, upper continental crust and Jiaxian Red Clays in China, b)to examine the geochemical behaviors of certain elements and their ratios such as Al2O3/Na2O, Na2O/K2O, MgO/TiO2, Rb/Sr and Chemical Index of Alteration (CIA) during pedogenesis and finally, to reconstruct the early Pleistocene climate. Materials and Methods This study was carried out on a 19-m-thick sequence of deposits exposed in a limestone quarry located near the Agh Band village of Golestan province in the east of the Iranian Loess Plateau (latitude 37.688889 N and longitude 55.158333 E). The so-called Agh Band red sequence underlies an upper Pleistocene loess-paleosol sequence and covers yellow limestone of the Akchagyl formation belonging to the Upper Pliocene of Kopet Dagh sedimentary basin. It is the first sequence one of red soils described for the loess plateau of Iran. Based on the paleomagnetically dating, this section is formed during ~2.4-1.8 Ma. The present-day climate of the study area is semi-arid, with mean annual precipitation and temperature of ca. 300 mm and 17◦ C, respectively. The soil moisture regime is Xeric-Aridic and the temperature regime is Thermic. In a field campaign in autumn 2014 the morphological characteristics of the section were recorded. Based on field observations, the sequence has been subdivided into 24 units, designated consecutively as U1-U24 from the top of limestone to the bottom of the Upper Pleistocene Loess. From each unit, representative samples were taken for color measurements, grain-size and geochemical analysis. Each air-dried sample was gently crushed, taking care not affect the grain size, and then measured using a Konica-Minolta CM-700 color meter. Grain size was measured using a Malvern Mastersizer 2000 laser grain-size analyzer following the pre-treatment procedures described in the text and the concentrations of major and trace elements were determined using a PANalytical PW2403/00 X-ray fluorescence spectrometer. All of the measurements were made in the Key Laboratory of Western China’s Environmental systems, Lanzhou University.Results and Discussion The grain-size distribution of the red section is dominated by fine-grained silts with the average of 86.6 percent, in addition, the amount of clay and sand are 10.9 and 2.6 percent, respectively. Angular or sub-angular blocky structures are dominated in the red sequence. The section is mainly characterized by alternations of reddish yellow )10 YR 6/6) and brownish-red (7.5 YR 3/6) to reddish (5YR) layers. In general, the color of the soil horizons in the red deposits is much redder than that in the overlying loess (7.5YR vs.10YR, respectively), and this is one of the principal differences between the red soils and the overlying loess. Another different is the amount of carbonate nodules and the size of them (up to~20 cm diameter). These soils have been subjected to relatively intensive pedogenesis, as demonstrated by the presence of clay skins and Fe-Mn coatings. The high correlation of major and trace element compositions between Agh Band red soils section, upper loess and paleosol and the Jiaxian red clay in China supports the proposal that the Agh Band red soils was wind-blown in origin. The value of CIA index (69.6 for red soils versus 59.8 for the upper loess deposits), Al2O3/Na2O, K2O/Na2O and Rb/Sr ratios are higher in the red deposits than in the upper Pleistocene loess, also, the lower amount of MgO/TiO2 ratio in reddish soils, suggesting stronger chemical weathering and thus a wetter climate during the formation of red soils in early Pleistocene.Conclusion Finally, our main findings are as follows: 1) The geochemical composition of the red-colored sedimentsis similar to the overlying upper Pleistocene loess suggesting a similar origin; 2) wind-blown origin of the red deposits and continuous atmospheric dust deposition in the Iranian Loess Plateau during the Early Pleistocene; 3) red soil sequence formed under wetter and more humid climate compared with the Upper Pleistocene loess.
Volume 37 - Issue 2
Soil Genesis and Classification
R. Taghizadeh-Mehrjardi; F. Sarmadian; M. Omid; N. Toomanian; M.J. Rousta; M.H. Rahimian
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976, Pages 101-115
Abstract
In recent years, there has been a great development in the digital soil mapping which has led to production of maps for countries and the continents. Although many studies have been conducted all over the world, few Iranian soil scientists have shown interests in digital mapping. Therefore, in the present ...
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In recent years, there has been a great development in the digital soil mapping which has led to production of maps for countries and the continents. Although many studies have been conducted all over the world, few Iranian soil scientists have shown interests in digital mapping. Therefore, in the present research, different data mining techniques (i.e. regression logistic, artificial neural network, genetic algorithm, decision tree and discriminant analysis) were applied to spatial prediction of great group soils in the area covering of 72000 ha in Ardakan. In this area, by using the conditioned Latin hypercube sampling method, location of 187 soil profiles was selected, which was then described, sampled, analyzed and allocated in taxonomic classes according to soil taxonomy of America. Auxiliary data used in this study to represent predictive soil forming factors were terrain attributes, Landsat 7 ETM+ data and a geomorphologic surfaces map. Results showed that decision tree model had the highest accuracy while it could increase the accuracy of prediction up to 44% in comparison with discriminant analysis technique. Results also indicated using the taxonomic distances led to improving the overall accuracy of decision tree up to 3%. Results confirmed capability of decision tree, artificial neural networks, genetic algorithm, logistic regression, and discriminant analysis with 70%, 65%, 65%, 55%, and 47% accuracy, respectively. Moreover, results showed that decision tree model could predict soil classes in sub-great group with the overall accuracy of 84.2%.
Volume 39 - Issue 2
P Khaji; N Enayatizamir; A Moezzi
Volume 41 - Issue 1
Soil Chemistry and Pollution
Alireza Zarasvandi; Majid Heidari; Ahmadreza Lahijanzadeh; Sedigheh Jalali; Mohsen Rezaei; Madineh Saed; Zahra Fereydouni
Abstract
Introduction Dust storms or sand storms are some of the meteorological phenomena that demonstrate differences with one another terminologically. These kinds of storms usually occur under arid and semiarid areas in circumstances which the blowing speed of a gale is higher than the erosion threshold. In ...
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Introduction Dust storms or sand storms are some of the meteorological phenomena that demonstrate differences with one another terminologically. These kinds of storms usually occur under arid and semiarid areas in circumstances which the blowing speed of a gale is higher than the erosion threshold. In other words, Dust and sand storms are persistent problems in the Middle East Region. The regional dust storms have bad effects on the health of human life which can cause asthma, bronchitis and lung diseases, due to their carrying micro-organisms (such as bacteria, fungi, spores, viruses and pollen) and their sharp edged particles. Several studies researches have shown that microorganisms mobilized into the atmosphere along with desert soils are capable of surviving long-range transport on a global scale. Dust-borne microorganisms in particular can. directly impact human health via pathogenesis,exposure of sensitive individuals to cellular components. The chemical components of dust are affecting the microbial life besides the precipitation, wind direction, time of day, season and atmosphere inversion conditions, all affecting the survival of total bacteria communities associated with dust particles, and the microbes are capable of surviving long distance transport. Dust storms have become a major environmental concern during the last decades in the oil- and gas-rich Khuzestan province in the southwestern Iran. Dust storms frequently occur in Khuzestan mainly during summer, and intense dust storms are particularly associated with easterly-blowing winds. High frequency (10-15%) and health outcomes of local dust storms in Khuzestan province, requires an extensive study on various factors of local storms such as heavy metal geochemistry and its environmental consequences are very important. In this paper, we present an overview of the geochemical and geo-environmental characteristics of dust storms in Khuzestan. Materials and Methods Information about dust storms of source and coverage was obtained from meteorological stations in Khuzestan province. In this study, airborne dust samples were collected to obtain TSP and PM10 by using the high-volume air (HVA) sampler model TCR. The geochemistry of airborne dust samples was analyzed at the Actlabs (Canada). The concentration of V, Co, Ni, As, Cd, Pb and Zn was determined in Actlab, Canada, using ICP-MS method. Results and Discussion The obtained results showed that Pb concentration in TSP samples ranges between 8.11 and 197 ppm with an average and median value of 23.6 and 11.15 ppm, respectively. The zinc content in PM10 samples, ranges between 4670 and 5000 ppm. Also, Ni has high concentration that ranges between 5.8 - 43.2 in PM10 samples. Lowest concentration of Cobalt is present in PM10 samples that ranges between 0.6 and 4.7 ppm. Vanadium has the highest concentration in Ahvaz samples. Also, PM10 samples include higher Arsenic concentration than TSP samples. Finally, Cd has the lowest concentration in all of the studied heavy metals with the mean value of 0.12 ppm. Positive correlation (0.9) between Cu with V, Co and Ni shows probably a similar source for these elements. Investigation of heavy metals concentration in various dust storms confirms that arsenic has a higher concentration in local storms. Seasonal studies show that V, Co and As have high concentrations in warm periods and Pb has the highest frequency in the cold season, in Khuzestan province. Based on the study of Contamination Factor (CF), the mean CF of heavy metals was in the order Pb > Zn > Cd >As > Ni > Co> V. Also, Degree of Contamination (DC) factor of the studied heavy metals in PM10 samples with mean value of 40 ppm is higher than TSP samples with average value of 10 ppm. In relation to the Enrichment Factor (EF) for V, Co, Ni, As, Cd, Pb and Zn, the EF mean of these metals was in the order Cd > Zn > Ni > Pb > As > V > Co. The highest Arsenic enrichment factor can be seen in PM10 samples. Conclusion The obtained results from calculation of Integrated Pollution Index (IPI) in PM10 samples showed that, V, Co, Ni and Pb are non-polluted. Also, Cadmium, Arsenic and Zinc showed a low, medium and high levels of pollution, respectively. Furthermore, based on IPI data in TSP samples, Co, As and V were non-pollution and Pb, Ni, Zn showed low level of contamination. Finally, Cadmium in TSP samples in dicated a high level of Integrated Pollution Index.
Volume 42 - Issue 4
M.J. Malekzadeh; M. Kiani Dehkiani; M. Sajadiyeh
Abstract
Introduction The limitation of fossil fuels and environmental pollution by using them have encouraged researchers toward renewable fuels. The most important renewable fuels are bioethanol, biodiesel and biogas. Biogas is a gas that is produced from biodegradable fermentation, agricultural products ...
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Introduction The limitation of fossil fuels and environmental pollution by using them have encouraged researchers toward renewable fuels. The most important renewable fuels are bioethanol, biodiesel and biogas. Biogas is a gas that is produced from biodegradable fermentation, agricultural products and wastes, animal waste and urban waste by anaerobic digestion. One of the products that has a significant amount of waste is sugar cane. This plant is widely cultivated in Khuzestan Province and annually produces a lot of waste which is currently not useful. One of the most important wastes is bagasse. Bagasse is the solid residues after crushing sugar cane and extracting it. Bagasse is composed of cellulose (45%), humiculus (27%), lignin (21%), extract (5%) and a small amount of inorganic salts (2%). A lot of bagasse is produced in sugar cane production process (about 240 kg with a moisture content of 50% per ton of sugar cane). Every year, a lot of bagasse is wasted. One of the most useful ways is to convert it into biogas and provide the percentage of the required thermal and electrical energy of the plant. Therefore, in this study, the effect of temperature and percentage of cow manure as an additive on biogas production from bagasse sugar cane was investigated. Materials and Methods The used bagasse in this research was provided from Farabi industry and Cultivation, located 48 km from Ahwaz, and a cow manure was provided from a livestock farm in Hamidieh, Ahwaz. In order to increasing the production efficiency of biogas, sugar cane bagasse was milled. Batch reactors of 4 liters was used to produce biogas from sugar cane bagasse. To control and maintain the working temperature, the reactors were placed in a water bath and the temperature of the bath was kept constant by using the thermal element and the thermostat. Cow manure was used to provide source of microorganisms. Cow manure with 5, 10, 15 and 20% weight percentages (B5, B10, B15 and B20) was blended with bagasse (numeric index of B indicates the percentage of cow manure in the blends). Sodium bicarbonate was used to control the pH of the reactors. Stirring was carried out manually in order to homogenize the materials and prevent the formation of hard layer at the top of the reactors. The amount of produced biogas was daily measured by water displacement method. Another measured parameter was the total Solid Index (TS), which represents the percentage of organic and inorganic matter for materials of the reactors. The experiments were carried out by using eight reactors for 30 days and the results were analyzed by completely randomized factorial design. Results and Discussion The results of variance analysis of biogas production in terms of bagasse to cow manure ratio and temperature changes showed that they had a significant effect at 1% level on biogas production. Considering the interaction effects of temperature and bagasse to cow manure ratios have a significant effect on the produced biogas at a 1% level. The results showed that with increasing in the percentage of cow manure in the materials, the amount of biogas production increased at both temperatures, so that by increasing the ratio of cow manure in the blends from 5 to 20% at 35 and 45 ° C, the produced biogas increased by 27.78% and 81.83%, respectively. By increasing the percentage of cow manure in the blends, the number of microorganisms in the digestion increased, and as a result of their activity, the amount of produced biogas increased. It was also observed that with increasing the temperature of digestion from 35 ° C to 45 ° C, the biogas production for B5, B10, B15 and B20 blends increased by 19.82%, 22.5%, 15.85% and 80.8%, respectively. The highest amount of cumulative production of biogas was obtained 0.3 m3.kg.VS-1 for 45 ° C and 20% cow manure to bagasse ratio. Conclusion In this research, the effect of cow manure in blend of sugar cane bagasse and temperature on produced biogas was investigated. The experiments were carried out at two temperatures of 35 and 45 ° C, and four blends with different weight percentages from cow manure to bagasse (5, 10, 15 and 20 percent). The results showed that with increasing the percentage of cow manure in blends, the amount of biogas production increased. Also, with increasing temperatures from 35 ° C to 45 ° C, the production of biogas in all blends increased.
Volume 38 - Issue 1
N Kazemi; M Almasi; H Bahrami; M. J Shaykhdavoodi; M Mesgarbashi
Abstract
Introduction: Identifying and evaluating of variables that impact tractor performance needs correct size of the variables and their effects on parameters during the tractor operations. So it is necessary to measure accurately performance parameters for improving draft performance of tractor. Generally, ...
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Introduction: Identifying and evaluating of variables that impact tractor performance needs correct size of the variables and their effects on parameters during the tractor operations. So it is necessary to measure accurately performance parameters for improving draft performance of tractor. Generally, there must be a proper assessment and identification from operational parameters such as forward speed, slippage, drawbar pull, etc. In this regard, a lot of research has been conducted using various methods to measure and calculate these parameters under various soil condition and different implementations for achieving the maximum overall energy efficiency, analyzing various treatments and predicting experimental models. But to change soil physical properties and different reactions of machinery on the one hand and to do operations related to on the other hand, precision agriculture intervals between the measurement of performance parameters and making decision for applying operational changes in real condition of work should be as short as possible. These conditions are required to be an accurate system with high confidence ratio for executing, measuring and recording simultaneously in farm. Therefore it is necessary to develop data acquisition for calculating field performance parameters in new methods of farm management. Materials and Methods: In this study, nine different sensors were installed on a MF399 tractor for recording engine and wheel speeds, drawbar power, and fuel consumption. A processing unit was designed and the performance parameters values of tractors-implement were fed into a software to a maximum of 1000 data per second real time, and also remotely from 1.5 km distance in Excel Sheet .Early stage testing of different combinations of the nine sensors included pre-installation on the tractor with four wheels on the jack (In workshop, on tractor) and on the farm and asphalt. Results and Discussion: The results showed that for engine and wheels and the fifth wheel speed sensors (actual forward speed) are accurate the slip was calculated real time using ultrasonic flow meters with 150 cc.min-1 flow rate The lowest fuel consumption was related to the no load and stationery is also possible. About draft, load cell measures 10 Nm real time. Generally, to identifying and survey the effect of various variables on performance parameters of tractor-implements, also designing automatic control system, SSCM and spatial variability in accurate agriculture depend on accurate and precise performance data measurement and correct measurement of variables and changes of parameters during operation execution at the same time. So the installed system is designed in such way that it can measure real-time wirelessly 9 main variables to a distance of 1500 meters with max 1000 data per second including forward speed, speed of all wheels, engine speed, net fuel consumption, drawbar pull and performance parameters such as OEE% (overall energy efficiency), SFC (lit/kw-hr),SE (specific energy in Mj/ha), AFC(Ha/hr), average slip of rear and front wheel(%) , drawbar power (kw), draft(kn/m), FCha(lit/ha)… which are calculated based on the nine variables and display data in tables and graph on pc and finally save separately and totally measurement results and all raw data (pulses) in 10 worksheets into an excel file for any sensor.. It is obvious that number and type of parameters, measurement unit and table display are editable in averaged form and totally this system is installable on common tractors with trivial changes in Iran. However, RTPM (remote tractor performance monitoring) was tested in real conditions of work and of library and its performance was found to be satisfactory. With a tractor equipped with an accurate measurement tool and data acquisition unit, this study tries to make actual interval between receiving, processing and displacing data while it provides the right analysis of recorded changes for controlling automatically and applying instructions with types of operators installed on tractor or mounted instruments on it. Finally, it displays measurement results in such a way that they are understandable not only for researchers and designers of agricultural machineries but also for a regular operator. The system can be installed with minimal changes on all conventional tractors in Iran.
Volume 42 - Issue 1
Agricultural Machinery
Hamed Ghafarzadeh Zare; Ali Maleki; Mohsen Irani Rahaghi; majid Lashgari
Abstract
Introduction An important process in grain harvesting with the combine harvester is threshing the materials using the thresher unit. An ideal thresher is one that carries out complete threshing with maximum crop input and best grain separation while saves the shape and quality of the grain and minimizes ...
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Introduction An important process in grain harvesting with the combine harvester is threshing the materials using the thresher unit. An ideal thresher is one that carries out complete threshing with maximum crop input and best grain separation while saves the shape and quality of the grain and minimizes grain loss. The vibrations of this unit cause the threshing action to fail and combine harvester loss to increase; therefore, it is highly important to study the vibration produced in the threshing unit. Since measuring the vibration in all working conditions on the farm is expensive, one of the ways to achieve the mentioned objectives is to use a vibration model by the simulation methods in order to examine the effects of vibration on the machine’s and the operator’s performance. Using vibration modeling and dynamic analysis of the structure through a mathematical model, finite element, and modal analysis, the causes and effects of the vibration in different working conditions can be examined with minimum cost. The present study was aimed to carry out the dynamic analysis of combine harvester using operational modal analysis. Therefore, the nonparametric and frequency decomposition methods were used in order to extract values of natural frequencies and damping coefficients, and the information obtained from the modal analysis was utilized to design and update the finite element model of the thresher. Afterward, the vibration of the thresher was adjusted as much as possible by modifying the structure through the weight modification method. Materials and Methods To measure the vibration of the thresher in practical conditions, a piezoelectric accelerometer sensor DYTRAN/MODEL3255A2, an analyzer device, and a signal processing software MEscopeVES were employed. In order to carry out the analysis, the combine harvester was started in its normal conditions and all parts were set in operation. Due to the geometry of the structure, four points were chosen on the bearings of the threshing drum. Afterward, de-noising signals used in MATLAB were utilized to calculate the response power spectral matrix, and singular values decomposition method was applied to it. Finally, by drawing each singular value, resonance peaks of the system were determined with respect to different frequencies, and the system’s damping was estimated. In order to carry out the geometric modeling and the simulation of the thresher by finite element method, ABAQUS finite element software was employed. In order to compare the analytical and the experimental results of NFD value, the predicted and measured natural frequencies were calculated. Modifying the structure as one of the applications of the modal analysis is a technique to consider the effect of physical parameters of a structure on its dynamic properties, i.e. natural frequencies and mode shape in order to improve the structure’s dynamic behavior. In the present study, therefore, modification of the threshing unit was aimed to decrease its vibrations by changing the natural frequency. Due to its complexity, the process of modifying the structure can be carried out by changing the mass and hardness. As presented in the study, modification of the structure was conducted by changing the mass on the finite element model. Results and Discussion The purpose of this study is to determine the vibration characteristics and present a vibration model of the thresher. The vibration responses of the thresher were recorded in working conditions on the bearings of the thresher. Through investigating signal parameters, including root mean square, energy, and entropy in different speeds of the thresher, it was specified that these parameters had significantly higher values in the rotation speed of 1000 rpm compared to other speeds, which proved the disturbance in the rotation speed of 1000 rpm. By examining the range of the natural and excitation frequencies of the threshing unit and also considering the diagram obtained from decomposing the singular values of the power spectral density matrix and Campbell diagram, a resonance frequency was found for the given structure, which is the major cause of vibration in the thresher. Moreover, the speed of 1000 rpm was determined as the critical speed of the thresher. In order to reduce the level of vibrations, the thresher’s excitation frequency should be far enough from the natural frequency; therefore, the process of modifying the structure is carried out by changing the mass applied to the finite element model, and it was observed that the natural frequency of the first mode changed from 16.98 Hz to 12.4 Hz.
Volume 38 - Issue 2
M. Varnaseri Ghand Ali; A. Moezzi; N. Enayatizamir
Volume 39 - Issue 1
A. Mradani; N. Dibagar; A. Modares Motlagh
Abstract
Introduction Simulation of tire- soil models have called attention so far when compared to the expensive and time consuming experimental tests. Materials and Methods: To simulate the model, first the soil and different components of tire were designed separately. To design a research model, soil was ...
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Introduction Simulation of tire- soil models have called attention so far when compared to the expensive and time consuming experimental tests. Materials and Methods: To simulate the model, first the soil and different components of tire were designed separately. To design a research model, soil was considered as a single-layer material with a complete elastic- plastic behavior. Its elastic parameters such as Young’s modulus (E), potion ratio (ѵ) and two plastic parameters; friction angle (φ) and cohesion (c) were obtained through tri- axial and direct shear tests, respectively. The tests revealed that soil internal friction angle, cohesion and density were obtained at 36°, 0.003 kg/cm2, and 1600 kg /m3, respectively. The soil profile dimensions were considered as 3×1.2×2 so that there would be no impact on the results or tire position. The tire used for test belonged to a tractor tire type of 220/65 R 21 with 36 cm in width and external diameter of 80 cm with a radial structure, manufactured by Good Year company. Since in simulation of tire ignoring the details of tread design has a negligible impact on large deformations and dynamic loading of tire, the simulated tire in this research was simplified to include tread, carcass, and rim. To design the tread of tire, the incompressible hyper- elastic material features, with Mooney – Rivlin coefficients were considered. To design the internal rubber of the tire model, which includes the belt and carcass, the boosted multiplied elastic approach was used. The dimensions of the modeled tire were compatible with a real one. From the symmetric point of view, only the half of the tire was simulated and dynamically analyzed which decreased the running time. A reference point was defined in the center of the tire to let the speed and load to be exerted through the point. According to mobility of the tire, the torque of every test based on its acceleration was considered on axel (connector) and the movement was measured from two separate points. It is worth to note that the boundary conditions, loading, and material characteristics should be entered in ABAQUS software close to the real conditions. The experimental tests were conducted at different levels of travelling speed (0.4, 0.8 and 1.2 ms-1), dynamic load (2000, 3000 and 4000 N) and depth (0.1, 0.15 and 0.2 m) with measuring the soil vertical stress. The experimental tests of this research were performed in Urmia University using the soil bin testing facility. The system includes various sections such as soil bin in dimensions of 22×2×1 m, carriage, soil processing equipment, dynamic system, evaluation tools, and controlling systems. In order to start data acquisitioning and to supply required power for wheel carriage, an industrial three phase electromotor with 22 kW (30 hp) was used. Analysis of variance was performed using SPSS version 20. Results and Discussion To assess the performance of driven tire-soil model, numerical results were compared with preliminary experimental data. The comparison showed a reasonably good agreement between the simulated and measured soil vertical stress at the tire-soil interface under three different levels of forward speed, dynamic load and depth. Using both methods, the increase of speed led to the reduction in soil vertical stress at different combinations of dynamic load and depth. When tire speed increases, the time during which tire makes contact with soil surface decreases. Therefore, tire dynamic load cannot be transferred into the soil layers completely. Increasing the amount of tire vertical load led to the increase of soil vertical stress but the effect of dynamic load variations on soil stress at different depths was not in a similar manner. It was inferred that the effect of all independent variables as well as their interactions on soil vertical stress was significant. Conclusion In all combinations of vertical load and forward speed, the results of both numerical and experimental tests were close to each other in three different levels of soil depth, so that, driven tire _soil finite element model of this study can be considered as a model with a reasonable accuracy to evaluate tire-soil performance in different operating conditions. In all combinations of dynamic load and forward speed the results of both tests at three different depths were close to each other.
Volume 41 - Issue 4
Serve Moradi; Kamal Nabiollahi; Syed Mohammad taher hossaini
Abstract
Introduction Soil quality is the capacity of soil function to sustain plant and animal productivities, to maintain or enhance water and air quality and to support human health. Slope position and deforestation are known to influence soil quality and assessing the soil quality degradation is important ...
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Introduction Soil quality is the capacity of soil function to sustain plant and animal productivities, to maintain or enhance water and air quality and to support human health. Slope position and deforestation are known to influence soil quality and assessing the soil quality degradation is important to soil management. Soil-quality indices are a common and easy way to quantify soil quality; they can improve understanding of soil ecosystems and allow more efficient soil management Two soil indicator selection approaches, total data sets and minimum data sets have been widely used to evaluate soil quality. The region of Marivan in Kurdistan province is one of the forested areas of Zagros which has been threatened due to population growth and increasing demand for food and, some parts are now under agriculture land use. Based on the present reports, deforestation and cultivation on the sloping areas have started almost 30 years ago. The aim of this research was to assess the effect of forest degradation and slope position on soil quality index. Materials and Methods The study area is located in Kurdistan Province, about 10 km northeast of Marivan city, west Iran (46°24΄ 46°40΄E, 35°42΄ 35°50΄N). Two adjacent sites were selected, consisting of a natural forest and deforested cultivated land on a hill slope. Average annual precipitation and temperature are 813 mm and 13.8 °C, respectively. Soil moisture and temperature regimes are Xeric and Mesic, respectively. Forests of the study area are relative intensive and their main forest vegetation is oak. In this study, 24 soil samples (0–20 cm depth) were taken from four slope positions (shoulder, back slope, foot slope and toe slope) of forest and adjacent deforested cultivated soils. Eight profiles (on each slope positions of both land uses) were also described. Fifteen soil properties: pH, electrical conductivity, sodium adsorption ratio, organic carbon, cation exchange capacity, carbonat calcium equivalent, soil erodibility, soil porosity, mean weight diameter of aggregates, available water, soil microbial respiration, available phosphorous, available potassium, total nitrogen, bulk density, were measured for 24 soil samples (0–20 cm depth). These Fifteen soil properties were applied as the total data set. Then, seven soil properties were selected as minimum data set using principle component analysis. Weight and score of each property were found using communality and scoring function (including more is better, low is better and optimum) and finally weighted additive and nemoro soil quality indices was computed. Results and Discussion: Seven soil properties (including soil organic carbon, cation exchange capacity, bulk density, soil erodibility, plant available water content, available potassium and total nitrogen) were selected as total data set using principle component analysis. The soils formed in low slope positions had higher depth and evolution compared to high slope positions. The results also showed land use change of forest land to cropland has led to degradation of Mollisols. The results showed that the mean values for weighted additive and nemoro soil quality indices in the deforested were significantly lower compared to forest. The mean values for weighted additive and nemoro soil quality indices in the shoulder were significantly lower compared to other slope position. significantly Strong Pearson correlation coefficients (0.98) were obtained between computed weighted additive soil quality index using total data set and a minimum data set. Conclusion: The results showed that forest degradation in the Marivan region led to a decrease in weighted additive and nemoro soil quality indices through a significant reduction of organic carbon, microbial respiration, total nitrogen, CEC, soil porosity and available moisture and significant increasing of bulk density, pH, SAR and soil erodibility. Forest degradation and land use change also due to cultivation led to decrease in the organic carbon content and soil structure degradation of Mollic horizon. Therefore, Mollic horizon has converted to Ochric horizon and Entisols and Inceptisols have formed in cropland land use. Moreover, the results showed different slope positions affect weighted additive soil quality index and mark significant difference. The results also showed that using the weighted additive soil quality index and minimum data set method can adequately represent total data set (R2=0.98) and thus reduce the time and cost involved in evaluating soil quality. Slope positions and where forest was converted to agriculture were characterized by low values of weighted additive soil quality index, suggesting a recovery of soil quality through changing to sustainable practices.
Volume 42 - Issue 3
N. Asgari; S. Ayoubi; A. Dematte; H. Khademi
Abstract
Introduction Carbonates are an essential and prominent constituent of soil chemical properties particularly in arid and semiarid regions, in regards with soil productivity and conservation. The conventional techniques for assessing soil properties rely on direct laboratory measurements which are expensive, ...
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Introduction Carbonates are an essential and prominent constituent of soil chemical properties particularly in arid and semiarid regions, in regards with soil productivity and conservation. The conventional techniques for assessing soil properties rely on direct laboratory measurements which are expensive, time consuming and labor intensive. Hence, it is required to develop fast and cost-efficient techniques for evaluation of mentioned parameters. The Koppen climatic classification generally categorizes Iran among the arid and semi-arid climates. About 90 % of its lands are arid or semiarid. According to Soil Survey Staff (2014), calcareous soils contain 5% or more volumes of inorganic carbon (or carbonate calcium equivalent), which are the prevailing formation in arid and semi-arid areas. These soils are typical of areas where minerals cannot be leached away from the soil profile due to low precipitation. Based on the reports of FAO.UNDP (1972), approximately 12% of soils all over the world and 65% in Iran are calcareous. Therefore, carbonate is a key component that physically and chemically influences soil properties, as well as its fertility and productivity. One of the fast, easy-to-use, cost-effective and non-destructive methods of soil analysis is the visible to near-infrared (Vis-NIR) and mid-infrared (mid-IR) spectroscopy, that can partly be employed for the optimization of traditional techniques. Therefore, the reflectance spectroscopy is considered as one of relatively inexpensive and fast techniques to evaluate these features. The purpose of the present study was to evaluate the capability of the reflectance spectroscopy technique in Vis-NIR (250-2500 nm) and mid-IR (400-400 cm1-) ranges to estimate soil carbonates content as one of the key components affecting the physical and chemical properties of soils (especially in arid and semi-arid regions). Materials and Methods The study area is located in Juneqan District, Chaharmohal and Bakhtiari Province, southwest of Iran. 272 soil samples were collected from a depth of 0-10 cm, air dried and passed through a 2 mm sieve. The carbonates value of each sample was determined by standard laboratory method. The spectral reflectance of soil samples was extracted in the Vis-NIR (250-2500 nm) and mid-IR (400-400 cm1-) ranges using a spectroradiometer FieldSpec 3 (ASD-Analytical Spectral Devices, Boulder Colorado, USA) and Nicolet 6700 Fourier Transform Infrared (FT-IR) (Thermo Fisher Scientific Inc., Waltham, MA), respectively. In the next step, seven preprocessing methods included absorbance transformation (log [1/reflectance]) (Abs), multiplicative scatter correction (MSC), standard normal variate transformation (SNV), Savitzsky-Golay derivation (SGD), Continuum removal transformation (CR), Normalization in range <-1,>1 (Nor) and Detrend (Det), were performed over original spectra for correcting light scattering in reflectance measurements and data improvement before using data in calibration models. Afterward, The dataset (272 samples) for each spectra range was randomly divided in calibration (70%) and validation (30%) datasets. Four different calibration models were fitted over Vis-NIR and mid-IR spectra to develop carbonates prediction models including: Partial Least Squares Regression (PLSR), Support Vector Machine (SVM), Random Forest (RF) and Gaussian Process Regression (GPR). The evaluation of soil predicting models was done according to the value of R2, RMSE and RPD. According to some researches, RPD values more than 2 shows that the models provide precise predictions, values of RPD between 1.4 and 2 are considered to be reasonably representative, and values less than 1.4 indicate poor predictive value. Results and Discussion The carbonates content in studied samples ranged from 1 to 76% with an average value of 24.7%. Overall, carbonates content promoted increase of spectral reflectance intensity on several region of spectrum in both spectral ranges. The specific absorption wavelength in Vis-NIR spectra used to indicate the presence of soil carbonates was 2338 nm and in the mid-IR range were 714, 850, 870, 1796, and 2510 cm1. The results showed that the best performance of the used models in the Vis-NIR spectral range was related to the SVM model (R2=0.81, RMSE=5.36) and in the mid-IR range allocated to PLSR model (R2=0.86, RMSE=4.5). Both of these models showed great accuracy in carbonates estimating (RPD>2). Besides, the results showed that the mid-IR spectral range in the prediction of carbonates provided better performance than the Vis-NIR range. This can explained by the fact that the fundamental molecular vibrations of soil components occur in the mid-IR range, while only their overtones and combinations are detected in the Vis-NIR range. Conclusion It seems that the reflectance spectroscopy technique can be considered as a precise substitute for the conventional methods of measuring carbonates, which are sometimes costly, time consuming and destructive. However, due to the spatial and temporal variability of soil properties as well as the huge variety of models and spectral preprocessing methods, it is necessary to examine the capability of this technique in other areas with other preprocessing methods and regression models.
Volume 42 - Issue 2
Soil Chemistry and Pollution
Neda Moradi; Mir Hassan Rasouli-Sadaghiani
Abstract
Introduction Recently, due to the enhancement of industrialization, urbanization, and disposal of wastes, fertilizers, and pesticides the concentration of heavy metals in agricultural soil has increased. Heavy metals are a serious threat to the environment due to their hazardous effects. Heavy metal ...
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Introduction Recently, due to the enhancement of industrialization, urbanization, and disposal of wastes, fertilizers, and pesticides the concentration of heavy metals in agricultural soil has increased. Heavy metals are a serious threat to the environment due to their hazardous effects. Heavy metal contamination of the soil is of particular attention due to food security issues and several reported health risks to both human and living organisms. In addition, large areas worldwide are polluted by lead (Pb). One of the major problems in the process of Phytoremediation is the low solubility of heavy metals, such as lead in the contaminated soil. Phytoextraction is a solar-driven remediation technology which greatly reduces the costs and has minimum adverse side effects. Lead (Pb) is among the highly toxic and most common heavy metals at contaminated sites. It originates from various anthropogenic sources and causes a variety of health, environmental, and ecological problems. The weed plant species are usually of the quickly growing nature and have higher biomass under unfavorable environments. Their phytoremediation potential could be more effective in reducing food chain contamination and consequently the risk to human health. Therefore, the objective of this study was to assess the Pb remediation potential of Artemisia (Artemisia absinthium L.) and Xanthium (Xanthium strumarium L.) in contaminated calcareous soil. Materials and Methods This study was carried out under a greenhouse condition as a factorial experiment based on a randomized complete block design with two factors, including Pb concentration in four levels (0, 250, 500, and 1000 mg Pb kg-1 soil) and plant type in two levels of Artemisia (Artemisia absanthium L.) and Xanthium (Xanthium strumarium L.) and in three replications. In this study, the soil was selected and was spiked with 0, 250, 500, and 1000 mg Pb kg−1 soil. Then plants were grown in pots containing the contaminated soil. At the end of the growth period, the dry weight of root and shoot, Pb concentration in the root and shoot of plants, and soil bioavailable Pb were measured. Also, the tolerance index (TI) of root and shoot was calculated by dividing the dry biomass of plant in each treatment by dry biomass in the control treatment at Pb0 mg kg-1 of the soil. Moreover, the stabilized Pb in roots (MS) and extracted Pb by shoots (ME) were calculated. For evaluating the ability of plants on uptake and shoot and root accumulation of Pb, mBCF (Modified bioaccumulation factor) and mBAF (bioconcentration factors) of shoot and root were calculated by dividing the Pb concentration in plant dry matter to bioavailable Pb concentration in soil and dividing the Pb accumulation in the plant fraction bioavailable metal content in the soil. In addition, the modified translocation factor (mTF) was calculated by dividing the Pb concentration in shoot dry matter by Pb concentration in root dry matter. Results and Discussion Results of this study indicated that with increasing soil Pb contamination, the root and shoot dry weight and tolerance index of plants decreased, while shoot and root Pb concentration, stabilized Pb in roots and the extracted Pb from shoots increased. The highest and lowest relative shoot and root dry weight were observed in Pb0 and Pb1000 treatments, respectively. There was no significant difference in the tolerance index (TI) of plants. In this study, roots and shoots mBCF, obtained for both plants and different levels of Pb in soil, were above unity, indicating that the plant is able to take up and accumulate Pb. A. absanthium PGPR had higher mTF than X. strumarium plant at every concentration of soil Pb. The assessment of the phytoremediation performance clearly revealed that the amounts of all phytoextraction indices in A. absanthium were higher than X. strumarium, while all phytostabilization indices in X. strumarium were higher than X. strumarium. In general, maximum Pb accumulation for root was recorded for X. strumarium (average of root mBAF, mBCF, and mTF 1.65 %, 5.48 and 0.97, respectively) and maximum accumulation of Pb in shoot was observed for A. absantium (average of shoot mBAF, mBCF, and mTF 2.79 %, 2.86, and 1.84, respectively). Conclusion It could be concluded that X. strumarium and A. absanthium, with high biomass in native condition, might be effective in phytostabilization and phytoextraction of Pb, respectively, especially in low levels of soil Pb contamination (250 and 500 mg kg-1).
Volume 40 - Issue 2
Soil Biology, Biochemistry and Biotechnology
S. A. Hosseini; mhsen olamaee; S. A. Movahedi Naeini; F. Khormali; R. Ghorbani Nasrabadi
Abstract
Introduction Potassium is one of the essential and macro elements in the growth of plant cells. This element plays an important role in improving the quality of agricultural products. The amounts of available potassium levels in most soils decrease more quickly and potassium balance is disturbed in many ...
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Introduction Potassium is one of the essential and macro elements in the growth of plant cells. This element plays an important role in improving the quality of agricultural products. The amounts of available potassium levels in most soils decrease more quickly and potassium balance is disturbed in many fields. Cultivation and lack of the application of potassium fertilizers in agricultural soils of Iran have caused the depletion of potassium and the amount of available potassium in most soils has reached below the critical level. The compensation of depleted potassium in the soil through indigenous resources and use of potassium bio-fertilizers is therefore very important. Weathering of silicate minerals by bacteria is considered as one of the essential K source for plant growth and development. The objective of this study was to isolate and identify potassium solubilizing bacteria from the shale containing glauconite mineral in Golestan Province and determine some traits related to plant growth promotion and selecting a superior strain in order to incubate in wheat lands. Materials and Methods Accordingly, a total of 5 samples 1 kg of rhizosphere of wheat from a depth of 0 to 30 cm and 5 samples 1 kg from shale stone (containing glauconite) were collected from Aitamir formation in Golestan Province in May 2015 and were transferred to the laboratory of Gorgan University of Agricultural Science and Natural Resources. Isolates were transferred to Aleksandrov media containing glauconite and muscovite and incubated for 10 days and the isolated strains were stored in the refrigerator at 4 oC. The amount of potassium release in solutions after 10 days was measured. Some biochemical and morphological properties of isolates were determined based on standard methods. PGPR tests were done in the isolates which were morphologically different and had high potential in releasing K. Finally, a strain whith high ability in releasing potassium and growth promoting properties was identified using nucleotide sequence of 16S rRNA gene. Results and Discussion Results showed that 40 strains from the first stage, 20 strains from rhizospherial soil and 20 strains from the soil resulting from glauconite mineral powders were isolated. Biochemical and potassium release tests showed that the highest released potassium was related to isolate No. 39 with an amount of 34.2 mg l-1 in muscovite, and 31.8 mg. l-1 in glauconite. The amount of siderophore produced in the superior strains showed that the lowest and the highest ratios of the diameter of the colony, were 1.12 and 3.1 related to isolate No. 19 and No. 39, respectively. The highest and the lowest auxins produced were also related to the isolate No. 39 and No. 27 with the amount of 52.25 and 5.15 mg per liter, respectively, measured at 72 and 96 hours. The results showed that the soluble phosphorus between different isolates was significantly different (P <0.05), its greatest concentration at 72 hours was related to isolates No. 39 with an amount of 295 mg per liter and the lowest at 24 hours was related to isolate No. 31 with an amount of 80 mg per liter. Also, the production of hydrogen cyanide test showed that none of the isolates was capable of producing siderophore. The obtained results from nucleotide sequence of 16S rRNA gene showed that the selected strain belonged to Arthrobacter phenanthrenivoran species. Conclusion It can be concluded that silicate bacteria contribute to the dynamics and mineralizing of elements in the soil and eventually K release from glauconite containing shale minerals mainly by reducing rhizosphere pH, the secretion of organic anions and complex formation with the surface cations of mineral and secreted extracellular Polysaccharides and soluble compounds and decomposition of soil organic matter. Among 40 isolated strains and the various tests and the results of released potassium in both minerals, the results showed that the potential of potassium releasing was different between the tested strains. Moreover, this study showed that in addition to the effect of these strains on potassium releasing, siderophore production, auxin and inorganic phosphate solubility, they can be effective in plant growth and in land inoculation. This study revealed the potential of indigenous bacteria species in the release of K from shale containing glauconite. It is anticipated that shale containing glauconite can provide a part of the need of the crops for potassium.
Volume 40 - Issue 1
N. Monjezi; H. Zaki Dizaji; M.J. Sheikhdavoodi; A. Marzban; M. Shomeili
Volume 43 - Issue 1
Zahra Masoudi; A. Jafari; Mohammad Hady Farpoor
Abstract
Introduction: Soil maps are a common source of information for land suitability studies. Land suitability studies are to compare land characteristics with the needs of land-use types and to select the best land-use productivity types for cultivation. Land evaluation analysis is considered as an interface ...
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Introduction: Soil maps are a common source of information for land suitability studies. Land suitability studies are to compare land characteristics with the needs of land-use types and to select the best land-use productivity types for cultivation. Land evaluation analysis is considered as an interface between land resources and land use planning and management. However, the conventional soil surveys are usually not useful for providing quantitative information about the spatial distribution of soil properties that are used in many environmental studies. Development of the computers and technology lead to develop the digital and quantitative approaches in soil studies. These new techniques rely on the relationships between soil and the environmental variables that explain the soil forming factors or processes and finally predict soil patterns on the landscape. Different types of the machine learning approaches have been applied for digital soil mapping of soil classes. To our knowledge, most of the previous studies applied land suitability evaluation based on the conventional approach. Therefore, the main objective of this study was to assess the performance of digital mapping approaches for the qualitative land suitability evaluation in the Jiroft plain of Kerman province. Materials and Methods: An area in the Jiroft plain of Kerman Province, Iran, across 28º14′ and 28º 26′N, and 57º 30′ and 57º 46′E was chosen. The study area is placed on alluvial plain, gravelly alluvial fans, eroded hills. Based on Google Earth image, geomorphology and topography maps and also field survey, 62 pedons were selected and excavated, and soil samples were taken from different soil horizons. Then, soil physicochemical properties were determined. To assess the climate, the climate information obtained from the Jiroft Synoptic Station. The average of soil properties was determined by considering the depth weighted coefficient up to 100 centimeters for potato. Qualitative land suitability evaluation for potato was determined by matching the site conditions (climatic, hydrology, vegetation and soil properties) with studied crop requirement tables presented by Givi (5). Land suitability classes were determined using parametric method. Land suitability classes reflect degree of suitability as S1 (suitable), S2 (moderately suitable), S3 (marginally suitable) and N (unsuitable). For digital approach, multinomial logistic regression (MLR) was used to test the predictive power for mapping the land suitability evaluation. Terrain attributes (elevation, slope, aspect, wetness index and multiresolution valley bottom flatness (MrVBF)), remote sensing indices (normalized difference vegetation index (NDVI), perpendicular vegetation index (PVI), and ratio vegetation index (RVI)), geology map, and geomorphology map were used as auxiliary information. Finally, all of the environmental covariates were projected onto the same reference system (WGS 84 UTM 40 N). Training and validating the model was done by leave-one-out cross validation. The accuracy of the predicted soil classes was determined using error matrices and overall accuracy. Results and Discussion: The results showed that climatic conditions are suitable (S1) for potato. The most important limiting factors were the gravel content, soil acidity and soil salinity for potato growing in the study area. Land suitability classes S2 to N were determined based on land index in the study area. The modelling results demonstrated overall accuracy 0.47 and 0.25 for class and subclass of land suitability, respectively. It seems that low number of soil samples for training and validating of the model were probably caused to low accuracy as compared to the other researches. In addition, the overall accuracy decreased from class to subclass. The terrain attributes (slope and aspect), remote sensing indices (normalized difference vegetation index) and geomorphology map were the most important auxiliary information to predict the land suitability classes and subclasses. This indicates the importance of geomorphological processes for determining the land suitability class in the study area. Conclusion: Results suggest that the land form, land position and geomorphology processes affect soil properties and then, land suitability classes. Therefore, variability of land suitability classes is function of variability of soil properties. Digital approaches could help to obtain the information with high resolution, provided that the criteria of suitability are associated with variability of soil properties. Although digital mapping approaches increase our knowledge about the variation of soil properties, integrating the management of the sparse lands with different owners should be considered as the first step for optimum soil and land use management.
Volume 47 - Issue 1
Precision Agriculture
Adel Taherihajivand; kimia shirini; sina samadi Gharehveran
Abstract
Introduction In many countries, on average, more than 50% of people's food comes from grains, and nearly 70% of the cultivated area of one billion hectares of the world is dedicated to grains. A variety of weeds grow along with cereals in the fields, which can reduce crop yield due to competition for ...
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Introduction In many countries, on average, more than 50% of people's food comes from grains, and nearly 70% of the cultivated area of one billion hectares of the world is dedicated to grains. A variety of weeds grow along with cereals in the fields, which can reduce crop yield due to competition for light, water and nutrients. To eliminate weeds accurately and with minimal problems, timely detection with high accuracy and speed is required. be done. In the field of agriculture, it is controlling and eliminating weeds in grain fields. Weeds are one of the most important factors affecting the production of agricultural products, which are their most important competitors in conventional agriculture, they spray the entire field to eliminate weeds, while weeds appear scattered and patchy in the field. which shows the necessity of using precise agriculture to solve this type of heterogeneity. In addition to causing economic damage, the conventional method of fighting can cause pollution of the environment and even the human food chain. Research shows that the losses caused by pests, diseases and weeds can reach 40% of the global crop every year and it is predicted that this percentage will increase significantly in the coming years. Besides, according to the research of Goktoan et al., the annual cost of weeds for The Australian economy is estimated to be around $4 billion as a loss in agricultural income.Materials and Methods Among the new methods in this field is the use of machine vision technology and related methods such as deep learning object detection algorithms and convolutional neural networks (CNN). The steps related to the implementation of the project include preparing data for training and evaluating networks, using new object detection algorithms, using different convolutional neural networks with different characteristics to extract image features in algorithms, and using the Feature Pyramid Network (FPN) method in object detection algorithms. Was. The output of the networks was evaluated in terms of the number of detections, the exact location of detection and the time of detection in the field. ViTs is based on the Transformer architecture that was originally developed for NLP tasks. Transformers use self-awareness mechanisms that allow the model to capture complex relationships between elements in a sequence. In the case of ViTs, sequence elements are image patches. In using the transformer architecture for visual data, it is dividing the image into small and non-interfering parts. Each patch typically consists of a grid of pixels. These patches are considered the "words" of the image sequence. Spatial embeddings are added to image patches to provide spatial information to the model. Spatial embeddings are necessary because transformers do not have built-in notions of order or spatial relationships. ViTs use multi-series self-awareness mechanisms to capture relationships between different image patches, and the representation of each patch is updated by attention to other patches. Data separation is very important in data watch transformers for two reasons a) the model needs data to learn and b) we need data to measure the model because the model may not be able to extract the information correctly.Results and Discussion The best network in terms of positioning accuracy was the transform model (ViTs) with an average accuracy of 0.95. In addition to this, the network considered in this research managed to recognize 503 of the 535 target weeds, and this means that our network is able to recognize 95% of these weeds. The presented method has been able to reach the highest accuracy compared to other existing methods and has been able to detect existing grasses in a much shorter period of time. Compared to other methods, the reset50 algorithm has been able to detect more than 88%, although its execution time is about 2.5 times that of the proposed method.In comparing the efficiency of algorithms, execution time is as important as accuracy. By making comparisons and considering 70% of the data as training data and 30% as test data, the presented algorithm has been able to detect the weeds in the field with an accuracy of over 90% in just 13 seconds.Conclusion: Today, deep learning methods are much more efficient than other methods, so we can use the new methods available in deep learning in the field of agriculture.Keywords: Optimization, accuracy, agriculture, weed, deep learningAll right reserved.
Volume 43 - Issue 2
Ali Monsefi
Abstract
Introduction Herbicides are chemicals that are used to inhibit the growth or to eliminate weeds in agricultural fields to increase the yield of crops in crop production. By the end of the 19th century, with the increasing labor supply problems, the need for chemical methods to control weeds became apparent. ...
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Introduction Herbicides are chemicals that are used to inhibit the growth or to eliminate weeds in agricultural fields to increase the yield of crops in crop production. By the end of the 19th century, with the increasing labor supply problems, the need for chemical methods to control weeds became apparent. It was first reported in France in the 1980s, that sulfuric acid was used in the fight against weeds in sugar beet fields. Nowadays, most of the herbicides used are organic herbicides, which share organic carbon in their chemical structure. The use of herbicides since about a century ago has been suggested as an effective way of eliminating crop competitors, though herbicides that remain in the soil for longer periods of time prolong weed control and thus increase weed management efficiency. On the other hand, their increased stability in soil may be of a magnitude that can damage crops in the following crop rotations. Soil properties can have a significant impact on the stability of herbicides in soil. Materials and Methods For this purpose, soil samples were taken from 0-30 cm depth from field of experiment No. 2 in College of Agriculture Shahid Chamran University of Ahvaz. After sampling and passing through 2 mm sieve, the physical and chemical properties were measured using standard methods. The pot experiment was conducted in a factorial completely randomized design with 32 treatments including soil salinity (at 2.5 and 6 dS / m), Ultimo herbicide rate (at 4 concentration levels of 0, 25, 50 and 100% Recommended dose) and planting time (60 and 120 days after herbicide application) with 3 replication. Wheat was selected as the experimental crop and variety was "Mehregan" which has been cultivated in most of Khozestan province. Herbicide was applied and soil was rested for 60 and 120 days then wheat was sown. For germination percentage, wheat seeds were sown directly in soil after germination test. After germination the percentages were recorded and kept in an equal number of plants in the pot. It should be noted that in order to eliminate the effect of nutrient deficiency on plant growth at appropriate intervals, nutrient solution was applied and irrigated according to the need of the plant.After 9 weeks (before flowering stage) the plant was harvested and the growth components including root length, root dry weight, shoot length, shoot weight and nutrient concentration including nitrogen (in plant dry matter), phosphorus, potassium, calcium, magnesium, iron, zinc, copper and manganese were measured in the extract obtained from dry digestion of plant tissue (aerial parts of plant). Statistical analysis was performed using SAS software and mean comparisons were performed by Duncan's multiple range test. Charts were drawn using Excel software. Results and Discussion According to the results, increasing the level of herbicide decreased the growth parameters of the plant, which is intensive under salinity stress. The results showed that considering 60 days sowing after herbicide application, shoot dry weight in 100% RD herbicide application in salinity of 2.5 dS/m was 1.6 g which was not showed significant difference with 50% herbicide application under salinity of 6 dS/m. Therefore, in higher salinity levels lower herbicide dose can damage the plant as much as higher levels of herbicides in lower salinity, and lower levels of herbicides in more soil salinity produce more negative effects. By increasing planting time from 60 to 120 days the residual effects of herbicides on soil decreased and plant showed better yield. By increasing salinity level from 2.5 to 6 dS / m, all growth components of wheat decreased, except for shoot length and shoot dry weight, this significant decrease was not reported for other components. Conclusion Therefore, it can be concluded that selection of sowing time after herbicide application in crop rotations is very important and by selecting the correct time can greatly reduce the deleterious effects of consuming more herbicides.Planting wheat at 60 days after application of herbicide compared to 120 days after application of herbicide, decreased the growth components of the plant. Therefore, selection of wheat sowing time in crop rotation 60 days after application of herbicide (especially at 100% recommended dose) is not recommended in maize – wheat cropping system. Also considering soil chemical properties such as salinity as an influencing factor on herbicide behavior in soil can be effective in controlling residual effects of herbicides in soil and plant.
Volume 46 - Issue 4
Yasman Zilabpour; Mojtaba Barani; Mohammad Rafieinia; Elham Bidram; Mojtaba Yahyaabadi
Abstract
IntroductionNanotechnology involves nanomaterials that are less than 100 nm as an interdisciplinary and pioneering technology has solved many problems in the fields of agriculture. The use of iron nano-fertilizers in order to control the release of nutrients can achieve sustainable agriculture by reducing ...
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IntroductionNanotechnology involves nanomaterials that are less than 100 nm as an interdisciplinary and pioneering technology has solved many problems in the fields of agriculture. The use of iron nano-fertilizers in order to control the release of nutrients can achieve sustainable agriculture by reducing the consumption of chemical fertilizers. Nano CDs (carbon dots) are a new system or carbon material between molecule and condensed solid, which gathers the characteristics of nano effect, surface functional groups and carbon elements. Therefore, it shows three basic functions of optics, chemistry and biology, and has multiple functions and applications. In addition, the abundant hydrophilic functional groups on the surface of CDs, small size and other structural characteristics made it show great advantages in promoting crop growth and enhancing photosynthesis and stress resistance. The aim of this study was to investigate the effect of iron nano carbon dot fertilizer application on vegetative growth parameters of sorghum plant in a calcareous soil.Materials and Methods Iron nano carbon dots were synthesized with lemon juice (carbon source), ethylenediamine and iron sulfate (iron source) by hydrothermal method. Coating of nanoparticles with poly lactic acid was done by co-precipitation method. Characterization of iron nano carbon-dots to confirm the successful loading of iron on the surface of carbon dots and also successful coating was done by UV-VIS, EDAX, FTIR, TEM and SEM device analyses. Some chemical properties of nanocarbon dots such as pH, electrical conductivity and salinity index were measured. Sorghum cultivation was done in the greenhouse of Isfahan agricultural and natural resources research center with a factorial design in 3 replications. The first factor was foliar spraying in three levels (distilled water, iron sulfate and no coating iron carbon dot with a concentration of 3 per thousand) and the second factor was soil application of iron carbon dot (with and no coating) in 5 levels including iron carbon dot, no coating and coated each in two levels (5 and 10 mg Fe kg-1 soil). Foliar spraying of sorghum at the eight-leaf stage was carried out by iron carbon dot and iron sulfate with a concentration of 3 parts per thousand. After the plant growth period (4 months), growth parameters such as the number of leaves, stem height, stem diameter, and fresh and dry weight of stem and leaves were measured. Also, the concentration of iron in plants and soil was also measured.Results and Discussion No coating iron nano carbon dots had 4.98% total iron and polylactic acid coated carbon dots had 1% iron. According to the successful results on carbon dots, they were confirmed with UV-VIS and FTIR devices. Based on the results of leaf number (6/60), stem height (35.52cm), stem fresh weight (24.73 g plant-1), leaf fresh weight (24.39 g plant-1), leaf dry weight (5.37 g plant-1) and the dry weight of the stem (4.73 g plant-1) was related to the interaction effect of no coating iron carbon dot soil treatment with a level of mg Fe kg-1 soil 1 with carbon dot foliar spraying (concentration 3 per thousand). The highest amount of iron in the stem (211 mg kg-1) and leaf (186 mg kg-1) is related to the carbon dot iron soil treatment with a level of 10 mg Fe kg-1 soil and the highest amount in the soil (5.92 mg kg-1). It was related to the interaction effect of iron carbon dot soil treatment coated with polylactic acid polymer (level of 10 mg Fe kg-1 soil) with carbon dot foliar spraying (concentration 3 parts per thousand).Conclusion Among the foliar treatments with iron carbon dot and ferrous sulfate heptahydrate, the treatments that were in the group of foliar treatments with nano carbon dot iron had the most positive performance. The treatment of no coating iron carbon dot and then the treatment of iron carbon dot coated with polylactic acid, with level of 10 mg Fe kg-1 soil which simultaneously applied soil and foliar application with carbon dot with concentration 3 parts per thousand showed the best performance. Therefore, these two types of synthesized nano fertilizers are suitable for sorghum cultivation and can be used as a type of iron fertilizer for agricultural purposes.Keywords: Iron nano carbon dot, nano carbon dot coating, sorghum, foliar spraying
Volume 43 - Issue 3
Heydar Mohammad-ghasemnejad maleki; Morteza Almassi; nima nasirian
Abstract
Introduction Algae have demonstrated to be an efficient bio energy source because in contrast to sugarcane, soybean, canola and oil palm, algae are not edible, they are less expensive to produce, grow faster, allow higher yield and production rate per hectare, do not require clean water to grow, and ...
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Introduction Algae have demonstrated to be an efficient bio energy source because in contrast to sugarcane, soybean, canola and oil palm, algae are not edible, they are less expensive to produce, grow faster, allow higher yield and production rate per hectare, do not require clean water to grow, and have the potential of reducing carbon emission. Because of their small size (typically a few micrometer) and low concentration in the culture medium (0.5–2 gL-1), harvesting microalgae biomass is a major challenge. The main goal of this study was to demonstrate the proof of principle for harvesting of microalgae using electro-coagulation-flocculation and to investigation the influence of several important variable on the efficiency of the electro-coagulation-flocculation in harvesting and separating Dunaliella salina microalgae from the culture medium. This is a native species and halophyte microalgae with a different culture medium from the fresh water in terms of salinity and electrical conductivity. Materials and Methods In order to investigate the effects of five control variables (independent) was included: material of the electrodes on both levels of aluminum and iron; current intensity in the range of 300 to 1000 mA; time for electro-coagulation-flocculation, 5 to 20 minutes; the electrode gap, 1 to 3 cm; stirring speed between 0 to 400, on the recovery efficiency as the response variable (dependent) experiments based on multi factors response surface method (combining categorical with numeric factors) was designed.In this study, the experiments were made inside a batch reactor with an effective volume of 250 mm which is made of Pyrex glass. Two electrodes with dimensions of 5 × 5 cm and a surface area of 25 cm2 with distance 2 cm from bottom of the reactor in vertically state and in different stages were placed inside the reactor with distance of 1, 2 and 3 cm. The Voltage and required current in the reactor were provided with a digital DC power supply. The main pilot in shape of cubic rectangular which is made of plexiglass with dimensions 35 × 28 × 18 cm and the effective volume of 14 liters was designed and built, in order to test the results of optimal experiments. For designing an experiment, statistical analysis and optimization was used from the software Design-Expert.Results and Discussion In this study, the modified quadratic model was used to fit the microalgae recovery efficiency data obtained from each batch test. The coefficients of determination (R2), adjusted and predicted were respectively more than 0.98, 0.96 and 0.90, which indicated that the modified quadratic model could describe the microalgae recovery efficiency in the batch tests of this study successfully. The results indicated that the linear effect of control variable on the recovery efficiency is very statistically significant. Moreover with increasing the electric current intensity variable and ECF time, or reduce the distance between the electrodes, the recovery efficiency has increased significantly. Also by increasing stirrer speed from 0 to 200 rpm the amount of recovery efficiency is increased, and by increasing stirrer speed from 200 to 400 rpm the amount of recovery efficiency has decreased. The results showed that aluminum electrodes on the recovery of microalgae from the culture medium are more efficient than iron electrodes. In this study, were searched the optimal operating conditions with aims of maximization of the microalgae recovery efficiency. The maximum microalgae recovery efficiency of 98.06% was obtained at the current intensity of 999 mA, the time of 20 min, the electrode gap of 1.39 cm, the stirring speed of 222 rpm and with aluminum as electrode materialConclusion In this study was examined the effect of five control variables (independent) including: current intensity, electrode gap, ECF time, stirring speed and electrode material on the response variable (dependent) the recovery efficiency of Dunaliella salina microalgae from the culture medium. The modified quadratic model was used to fit the microalgae recovery efficiency data obtained from each batch test. The experimental results in different stages of our study indicated that the harvesting efficiency of the ECF process could be improved with optimized settings in different stages. If you want to achieve the maximum efficiency with considering economic factors, energy and environment, the second part of an article by the same research group that focuses on this topic is recommended. However, as the ECF process is complicated on a large scale, a pilot study is required to further adjust the harvesting efficiency and make alterations in current density and electrode plate distance in the ECF harvester so as to develop such technology and make commercial use of it in the future.
Volume 35 - Issue 1
F. i Karim; M.A. Bahmanyar; M. Shahabi
Volume 41 - Issue 2
Plant Nutrition, Soil Fertility and Fertilizers
banafsheh rezaee niko; Naeimeh Enayatizamir; mojtaba norozi masir
Abstract
Introduction Zinc is one of the imperative micronutrients required relatively in small concentrations in tissues for healthy growth and reproduction of plants. Zinc deficiency in plants leads to reduced membrane integrity and synthesis of carbohydrates, auxins, nucleotides, cytochromes, and chlorophyll ...
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Introduction Zinc is one of the imperative micronutrients required relatively in small concentrations in tissues for healthy growth and reproduction of plants. Zinc deficiency in plants leads to reduced membrane integrity and synthesis of carbohydrates, auxins, nucleotides, cytochromes, and chlorophyll and develops susceptibility to heat stress. The solubility of Zn is highly dependent upon soil pH and moisture and hence arid and semiarid areas are often zinc-deficient. The use of microorganisms with the aim of improving nutrients availability for plants is an important practice and necessary for agriculture. Zinc-solubilizing microorganisms can solubilize zinc from inorganic and organic pools of total soil zinc and can be utilized to increase zinc availability to plants. Therefore, the present study was carried out to isolate and characterize native zinc-solubilizing bacteria from Zea mays rhizosphere and evaluate their zinc-solubilizing potential and the effect of zinc solubilizing isolate on Zea mays growth.Materials and Methods: In vitro zinc solubilization assay of isolates was done using 0.1% zinc from zinc oxide in both plate and broth assays. Actively growing cultures of each isolates were spot-inoculated (7 µL) onto the agar and plates were incubated at 28°C for 48 h. The clearing zone around colony was recorded. Quantitative study of zinc solubilization was studied in 150 mL conical flasks containing 50 mL of liquid mineral salt medium. The broth was inoculated with 10 µL of overnight grown bacterial inoculum and incubated for 72 h at 160 rpm in an incubator shaker at 28°C. After incubation, the culture broth was centrifuged and the concentration of Zn in the supernatant was estimated in atomic absorption spectrophotometer. Among these isolates, 18 isolates with a solubility index of 1 and higher were selected based on morphological, biochemical and physiological characteristics for further studies. An isolate with more ability to dissolve zinc, phosphorus, potassium and auxin production were selected for investigation the effect of isolate on Zea mays growth. Maize seeds of cultivable variety were surface sterilized with 1% sodium hypochlorite for 5 min and washed several times with sterile distilled water. Seeds were treated with inoculum containing 108 cfu•g−1 of isolate. A factorial experiment in a completely randomized design with five replications was conducted. The treatments included two levels of bacteria B1 (control), B2 (Stenotrophomonas) and zinc sulfate fertilizer at three levels of Zn0 (control), Zn20 (20 kg/ha) and Zn40 (40 kg/ha). After 60 days of sowing, plants were removed from the tubes carefully and biometric parameters like root length, shoot length and dry mass of plants were recorded as the indicative of plant growth. Results and Discussion: A total of 50 bacterial isolates were isolated from corn rhizosphere. Of all, sixteen isolates showed solubilization halo on plate agar medium. Among the cultures, Z1, Z3, Z16 and Z12 showed the highest solubilisation zone in ZnO amended medium with maximum solubility index (1.3). Quantitative assay for zinc solubilisation revealed that Z14 were able to dissolve 44.8 ppm from ZnO in liquid medium. While solubility index of this isolate was lower that above mentioned isolates (1). Of all, the isolate Z14 with highest zinc solubilisation by broth assay was characterized and identified as Stenotrophomonasspecies based on Gram-negtive reaction and other biochemical and physiological properties. This isolate was able to produce auxin and dissolve insoluble phosphorus and potassium from the source tricalcium phosphate and vermiculte, respectively. One of these strains (Z14), Stenotrophomonas was used as inoculum in corn culture. Seed bacterization of maize with zinc solubilising Stenotrophomonas enhanced the plant growth significantly after 15 days. Results indicated a significant interaction effect of bacterium and fertilizer on shoot dry weight and chlorophyll content (p < 0.01). The maximum spad index and wet weight of aerial part obtained at present of bacterium and without using of zinc sulfate. The main effect of bacterium on wet and dry weight of root and wet weight of aerial part, root length and shoot height was significant (p < 0.01). َApplication of bacterium in all treatments caused to increased all measured parameters in th eperesence of zinc fertilizer or absence of zinc fertilizer.Conclusion: PGPR is known as a group of useful rhizospheric bacteria that increase plant growth. Today, the increasing use of PGPRs in agriculture as an alternative to chemical fertilizers to prevent environmental contamination.
Volume 41 - Issue 3
Land Evaluation and Suitability
Moslem Zarrini Bahador; Javad Givi; Ruhollah Taghizadeh Mehrjerdi
Abstract
IntroductionWheat is one of the key cereals that provides a nutrition source to millions of people around the world. By conducting applied studies, the limitations of soil and climate that reduce the yield per unit area must be understood and solutions should be provided to address these limitations. ...
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IntroductionWheat is one of the key cereals that provides a nutrition source to millions of people around the world. By conducting applied studies, the limitations of soil and climate that reduce the yield per unit area must be understood and solutions should be provided to address these limitations. One of these strategies is a detailed study and spatial prediction of yield at points with different soil and climate characteristics. Models that predict crop yield can estimate the yield regarding climate, landscape, soil and management constraints. Considering the arid and semi-arid climate of Iran, the shortage of yield per unit area and the growing population, the country needs new research and strategies to increase yield per unit area. For this purpose, the first step is to examine the spatial variations of the yield. In the present study, the factors affecting the rainfed wheat yield in order of importance and efficiency of different methods of estimating spatial variations were investigated and the predicted yield of this crop was mapped digitally. Materials and MethodsThe study area, with an area of 6700 hectares is located in Badr watershed, around Ghorveh city, Kurdistan province, west of Iran. The mean annual air temperature is 12.1oC and the average annual precipitation is 345.8 mm. The soils of the area were classified in the orders of Entisols, Inceptisols and Mollisols and in 32 soil families, according to the last version of Keys to Soil Taxonomy. Based on hypercube technique, 125 observation points were selected, soil profiles were dug and described at these points and soil samples were collected from horizons of the profiles. Some physical and chemical characteristics of the soils were determined according to the standard laboratory methods. Rainfed wheat yield was measured at each side of one soil profile in a 1m×1m quadrangle. In the present study, in addition to geomorphological data, different types of auxiliary variables such as some of the primary and secondary derivatives of digital elevation model (DEM) and Landsat satellite image data were used. To find out the affecting auxiliary topographic and plantcover data on rainfed wheat yield prediction in order of importance,ReliefAttributeEval algorithm of WEKA software was used. Artificial neural network, decision tree Analysis, discriminant analysis, and averaging k-nearest neighbors are the models that were used in this research for prediction of rainfed wheat yield. Results and Discussion Calcium carbonate, organic carbon and coarse fragments, respectively with variability coefficients of 174.4, 62.4 and 61.3%, had the highest variation and pH, CEC and sand, respectively with 3.6, 16.9 and 20.3% variability coefficients showed the least variability in the soils of the studied area. In addition to geomorphological data, the parameters that were taken from the digital elevation model include elevation, slope percentage, slope aspect, slope curvature, slope surface curvature, longitudinal curvature, slope relative position, wetness index, multiresolution valley bottom flatness index, multiresolution ridge top flatness index, valley depth, channel network base level, modified catchment area, catchment slope, catchment slope aspect and catchment height. The environmental parameters that were taken from the Landsat 8 satellite imagery, include the normalized differential vegetation and the soil-adjusted vegetation indices. The ReliefAttributeEval algorithm in Weka software, in order of decreasing importance, identified geomorphology, relative slope position, longitudinal curvature, multi-resolution ridge top flatness index, slope, normalized differential vegetation index and soil-adjusted vegetation index as the most important factors affecting rainfed wheat production in the studied area. The amount of rainfed wheat yield was predicted by the models of artificial neural network, decision tree analysis, discriminant analysis, and averaging k-nearest neighbors. The error criteria for this prediction and a significant correlation between measured and estimated values of the rainfed wheat yield, indicate a higher accuracy for the averaging k-nearest neighbors model, compared to other models. The spatial distribution of the rainfed wheat yield, predicted by the averaging k-nearest neighbors model, was mapped. In the Badr watershed, the yields are continuously reduced towards the mountains. In this landscape, as the slope increases, depth and water storage capacity of the soil decrease mainly in the presence of Entisols. These soils are seen in the eastern, southern and western parts of the watershed. At lower elevations, the soils are deeper and are mainly Inceptisols. Rainfed wheat yield increases in the piedmont landscape, including hill, glacie and alluvial fan. Conclusion In order of decreasing importance, geomorphology, relative slope position, longitudinal curvature, multi-resolution ridge top flatness index, slope, normalized differential vegetation index and soil-adjusted vegetation index are the most important factors affecting rainfed wheat production in the studied area. The averaging k-nearest neighbors model has a higher accuracy for rainfed wheat yield prediction, compared to other models. In the Badr watershed, the rainfed wheat yield is continuously reduced towards the mountains in the eastern, southern and western parts, where mainly Entisols are present. The yield increases in the Inceptisols, located on the piedmont landscape.
Volume 39 - Issue 2
A Shabani; A Gholamalizadeh Ahangar; S Golshahi
Volume 38 - Issue 2
M. Moeini; M. Hejazi Mehrizi; A. Jafari
Volume 39 - Issue 1
A. Fathi Gerdelidani; H. Mirseyed Hosseini; M. Farahbakhsh
Abstract
Introduction Phosphorus deficiency is one of the major problems of calcareous soils in Iran and based on current statistics more than 70 % of all soils in Iran are under critical P levels of 15 mg kg-1 (51). Previous research results show that application of organic matter increases P availability (46) ...
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Introduction Phosphorus deficiency is one of the major problems of calcareous soils in Iran and based on current statistics more than 70 % of all soils in Iran are under critical P levels of 15 mg kg-1 (51). Previous research results show that application of organic matter increases P availability (46) and changes the P distribution between various forms in calcareous soils.The aim of this study was to evaluate the effects of different levels of spent mushroom compost and sugar cane bagasse biochar as agricultural by products or crop residues on availability and phosphorus fractions in a calcareous soil from Karaj (Alborz provience, Iran). Materials and Methods The soil for the experiment was obtained from 0-30 cm depth of Agriculture Faculty farm of Tehran University at Karaj. Some physical and chemical properties were determined using standard methods (table 1). The spent mushroom compost (SMC) was from Malard mushroom factory and Sugarcane bagasse was from a farm in Khozestan. The Biochar (B) was prepared from the raw material heated to 500 degree celcius inside furnace for 3 hours. Some basic properties of SMC and biochar were also determined (table 2). The experiment was conducted in a completely Randomized design with 5 treatments, and 3 time periods with three replications of each treatment. Treatments included 2 biochar levels B1, B2 (15 and 30 Mg ha-1 respectively), 2 spent mushroom compost levels SMC1, SMC2 (20 and 40 Mg ha-1 respectively) and the control treatment (C). For each treatment, 300 grams of air dried soil was used in small pots and after application of materials and mixing they were moist to field capacity and kept inside an incubator at 28-29 ˚C for a period of 120 days. At 14, 60 and 120 days soils were sampled for analysis (by eliminating the pots). Soil properties such as pH, available P, water soluble P and various inorganic P fractions (23) were determined in soil samples. Statistical analysis of the data was done using SAS software and mean comparison using LSD method was also performed. Results and Discussion Results showed that the available P in the control increased significantly (p<0.01) from 8.8 mg kg-1 of soil to 17.8, 28.8, and 12.8 mg kg-1 of soil in the SMC1, SMC2, and B2 respectively, which had an increasing trend with time in B2, but in the SMC2 it was highest on 60 days. This can be related to higher microbial activity after application of organic materials and release of P after organic matter decomposition (22). The water soluble P also increased from 2.1 mg kg-1 in the control to 2.8 and 2.7 mg kg-1 in the SMC2 and B2 respectively, which showed an increasing trend over time for SMC2 (p<0.01). In the SMC treatments, part of the P content is in inorganic water soluble form and also in the biochar treatments some ash containing P soluble salts may be the source of increase in water soluble P content. The Ca2-P form in the control was increased from 5.1 mg kg-1 of soil to 11.1 and 16.2 mg kg-1 of soil in the SMC1 and SMC2 respectively, which had an increasing trend with time(p<0.01). During 120 days of incubation, the Ca8-P, and Al-P forms were also increased from 158 and 27 mg kg-1 of soil in the control to 186 and 35 mg kg-1 of soil in the SMC2 treatment (p<0.01). The distribution pattern of P fractions after application of SMC and Biochar was different and it changed with the level of the applied material. Conclusions: Based on the results of this experiment application of organic materials of different nature such as spent mushroom compost and sugarcane bagasse biochar to calcareous soils can affect the availability and various forms of phosphorus to the extent that it should be considered as a measure to improve P availability conditions.
Volume 41 - Issue 1
Micromorphology and Clay mineralogy
masoomeh najafinia; Fashad Kiani; mojtaba Baranimotlagh
Abstract
Introduction Loess sediments of northern Iran represent several cycles of climate change and evolution of the landform for the mid-to-late Quaternary. Climate change in elevations of Iran and its surrounding areas is very controversial in the mid and late Quaternary, and has been discussed in the past ...
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Introduction Loess sediments of northern Iran represent several cycles of climate change and evolution of the landform for the mid-to-late Quaternary. Climate change in elevations of Iran and its surrounding areas is very controversial in the mid and late Quaternary, and has been discussed in the past according to rainfall and rainfall periods and between rainfall, glacial and inter-glacial. Paleomegnatic results also indicate that these sediments have accumulated between, 1.8 to 2.4 million years ago. However, pedogenic processes and the effects of past climate in these soils still have not been fully investigated. The loess deposits in northern Iran are a valuable archive of regional paleoclimatic and paleoenvironmental information. Extensive sedimentological and chronological studies have been carried out on the middle to upper Pleistocene loess during the past decades, but it is necessary to do a comparative research on the older loess deposits. So, this study aimed to conduct a mineralogical and physicochemical investigation on the early Pleistocene loess and to compare it with modern loess soils in Agh-Band, Yelli-Badrag and Qareh-Agach in loess plateau of eastern Golestan. Materials and Methods The study area is located in a hot and dry climate in loess Plateau east Golestan. According to the previous studies, a total of six profiles were excavated and studied. Then, physicochemical properties such as soil texture, acidity (pH), electrical conductivity (EC), saturation moisture (SP), organic carbon (OM), cationic exchange capacity (CEC) and calcium carbonate equivalent (CCE) were measured in the laboratory. Clay separation was carried out with a specific method to separate the clay as well as identification of clay minerals. After preliminary field observations and determining the horizons for each profile in the region, soil classification was done based on soil taxonomy and WRB. Then, soil samples were prepared from each horizon for physicochemical and mineralogical studies in sufficient quantities. Results and Discussion Comparing the results of physicochemical properties (such as color, lime percentage, the cation exchange capacity and the ratio of iron, etc.) in paleosol and modern loess soils indicates that in paleosol soils, soil forming processes have passed several stages. Clay mineralogy is a good indicator for past climate change studies in loess.The existence of the arglic horizons and the evolved calcic in paleosols and their absence, in comparison with the modern soils in which they are present, indicate the change in soil formation conditions. The change in the color of paleosols also represents the soil moisture and the more suitable conditions of the past climate (temperature, and especially rainfall) in comparison with the present climate of the region, this color change was due to activation of soil formation processes in paleosols. All paleosol samples had a higher clay content than the late modern loess soils of the Pleistocene, suggesting favorable climatic conditions for soil formation processes and the development of more ancient soil than parent materials. Decrease in the amount of annual precipitation in the region, compared to the past, has led to decreased smectit and increased chlorite. Therefore, presence of smectit cannot be attributed to the present situation of the region. The presence of these clay minerals in paleosols can be due to wet weather conditions as well as weathering of clay mineral deposits. On the other hand, the dominance of less weathered clay minerals such as illite and chlorite in the late Pleistocene modern loess soils is correlated with the present dry climatic conditions. Conclusion The simultaneous presence of modern and old loess soils in the studied areas demonstrates the general evolution of geographical and climatic conditions during the Pleistocene period which has altered the properties of these layers and ultimately left out the effects of high clay conditions, which is a combination of climatic evidence and intermittent pedogenic soil formation processes. The presence of early Pleistocene loess soils between late Pleistocene loess sediments in Golestan province and the conditions of the study provided pedological and mineralogical comparisons of modern and paleosols in these areas and the results clarified a part of the climate change in northern Iran. The past climate study allows for prediction of the current and future climate change process. Therefore, a more accurate study of clay minerals as the key to all soil behaviors and past climate change in different parts of the eastern Golestan plateau can be very useful in completing studies of evidence of past climate change in paleosol soils
Volume 42 - Issue 1
Plant Nutrition, Soil Fertility and Fertilizers
Yaser Azimzadeh; Nosratollah Najafi; Adel Reyhanitabar; Shahin Oustan; Alireza Khataee
Abstract
Introduction Phosphorus (P) is an essential element for living organisms. Discharging P from various sources, such as industrial wastewater and agricultural waters, into surface water causes eutrophication and undermines the balance of aquatic ecosystems and imposes many costs due to water quality degradation. ...
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Introduction Phosphorus (P) is an essential element for living organisms. Discharging P from various sources, such as industrial wastewater and agricultural waters, into surface water causes eutrophication and undermines the balance of aquatic ecosystems and imposes many costs due to water quality degradation. In addition, mineral resources of P-fertilizers in the world are unrecoverable and are coming to an end. Therefore, it is very important to develop adsorbents to remove P from contaminated water and then be used as P-fertilizer for surmounting the eutrophication and P-fertilizer exhausting challenges. In the last few years, biochar and hydrochar have been considered as low-cost porous eco-friendly adsorbents with a high surface area and easy to produce and use. Biochar and hydrochar are carbonaceous solids that are produced from the carbonization of biomasses and could be used as adsorbents and soil amendments. However, because of their high negative charge and very low ability to absorb anions, especially phosphate, they cannot be used as phosphate adsorbents. In recent years, several methods have been introduced to change the surface of biochar and hydrochar to increase their anion adsorption capacity. In this respect, the successful results of the production and the use of engineered biochars, such as layered double hydroxides (LDHs) functionalized biochar (LDH-biochar) and LDH-hydrochar composites have been provided. Layered double hydroxides (LDHs) are brucite-like compounds with a large specific surface area, high positive charge, and exchangeable interlayer anions. LDHs functionalized biochar and hydrochar composites are environmentally friendly adsorbents for the removal of phosphate from aqueous solutions. Also, P-loaded LDH-biochar and LDH-hydrochar composites have the potential application as a P-fertilizer. These composites may increase soil available-P through the slow release of P and can improve soil properties and fertility due to the presence of the biochar and hydrochar in their structure. So, the P-loaded LDH-biochar and LDH-hydrochar may affect the availability of soil nutrients and plant growth. Nitrogen (N), P, and potassium (K) are the macronutrients that have a direct and great influence on plants growth. Therefore, the aims of this study were: (I) producing LDH-biochar and LDH- hydrochar composites and loading them with phosphate. (II) Investigating the effects of the biochar, hydrochar, LDH, LDH-biochar, LDH-hydrochar, the P-loaded LDH-biochar (LDH-biochar-P), and LDH-hydrochar (LDH-hydrochar-P) on dry matter and concentrations of P, N, and K in corn shoot and root. Materials and Methods Biochar was produced from applewood feedstock through slow pyrolysis at 600 ºC for 1 h under Argon flow conditions. Hydrochar was produced through hydrothermal carbonization of the applewood feedstock at 180 ºC and 11 bars pressure for 12 h. Then by precipitation of LDH particles on the biochar and hydrochar surfaces, LDH-biochar and LDH-hydrochar composites were prepared. The LDH particles were synthesized via a combined fast co-precipitation and hydrothermal treatment route. Each gram of LDH-biochar and LDH-hydrochar composites was loaded with 51 and 47 mg P, respectively. Then using a factorial experiment on the basis of completely randomized design with three replications, the effects of biochar, hydrochar, LDH, LDH-biochar, LDH-hydrochar, LDH-biochar-P, and LDH-hydrochar-P were studied in presence and absence of monocalcium phosphate fertilizer on corn dry matter and concentrations of N, P, and K in corn shoot and concentrations of P and K in corn root. Results and Discussion The results showed that the biochar had a higher yield and ash percentage, pH and electrical conductivity (EC) as compared with the hydrochar. The concentrations of all studied nutrients in the biochar, except for N, were greater than those of hydrochar and biomass. The P, K, Na, Fe, Mn, and Zn concentrations in biochar and hydrochar were significantly greater than the initial biomass. The application of P-fertilizer increased root and shoot dry matters in all treatments, except for LDH-biochar-P and LDH-hydrochar-P treatments. Biochar and hydrochar had no significant effects on root and shoot dry matter in non-P-fertilized treatments and had no significant effects on P and K concentrations of corn root and shoot. However, biochar and hydrochar increased shoot dry matter in P-fertilized treatments. The highest root and shoot dry matters, P concentrations of root and shoot, and N concentration of shoot were obtained in the presence of the LDH-biochar-P and LDH-hydrochar-P, and the lowest root and shoot dry matters of corn were observed in the presence of the LDH. Application of P-fertilizer increased P concentrations of corn root and shoot in the presence of the LDH-biochar and LDH-hydrochar but decreased the K concentration of root in biochar, LDH-biochar and no amendment treatments and had no significant effects on N and K concentrations in the shoot. The application of P-fertilizer decreased P translocation factor in presence of the LDH-biochar and LDH-hydrochar and had no significant effect on P translocation factor in all other treatments. Using P-fertilizer had no significant effect on K translocation factor in all treatments. Biochar, hydrochar, LDH, LDH-biochar, and LDH-hydrochar had no significant effects on P and K translocation factors. The translocation factor of P was greater than 1 in all treatments, except for the LDH-biochar-P and LDH-hydrochar-P treatments. Also, the translocation factor of K was greater than that of P in all treatments. Conclusion Due to the structural similarities between biochar and hydrochar, LDH-biochar and LDH-hydrochar, and LDH-biochar-P and LDH-hydrochar-P, the root and shoot dry matter and concentrations of the studied elements in corn root and shoot were not significantly different between the biochar and hydrochar, LDH-biochar and LDH-hydrochar, and LDH-biochar-P and LDH-hydrochar-P treatments, respectively. P-fertilizer had synergistic relationships with biochar, hydrochar, LDH-biochar, and LDH-hydrochar but antagonistic relationships with LDH, LDH-biochar-P, and LDH-hydrochar-P composites in terms of dry matter and P concentrations in corn root and shoot. So, applications of the biochar, hydrochar, LDH-biochar, and LDH-hydrochar accompanied by P-fertilizer and the use of LDH-biochar-P and LDH-hydrochar-P without the application of P-fertilizer can be proposed for corn cultivation under similar conditions.
Volume 41 - Issue 4
Plant Nutrition, Soil Fertility and Fertilizers
Ali Abdolahi; Mehdi Taghavi; Mojtaba Norouzi masir; Abdolamir Moezzi
Abstract
Nanotechnology has created a range of new applications in different stages of agriculture. The application of Nano-fertilizers for plants is of vital importance because of its unique properties, such as the specific surface and high reactivity. Many studies have investigated the effect of metal nanoparticles ...
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Nanotechnology has created a range of new applications in different stages of agriculture. The application of Nano-fertilizers for plants is of vital importance because of its unique properties, such as the specific surface and high reactivity. Many studies have investigated the effect of metal nanoparticles on yield and concentration of elements in the plant. The present study was conducted with the aim of investigating the effects of Functionalized Iron Oxide Nanoparticles (FIONPs) on plant yield, concentration and uptake of Zinc in root and shoots of wheat under greenhouse cultivation in a calcareous soil. Materials and Methods This study was conducted in the greenhouse condition as a randomized complete design with three replications. Treatment consisted of functionalized iron oxide nanoparticles (Hydroxyl: OH, Carboxyl: COOH and Amine: NH2) each at three levels (100, 200 and 300 mg.kg-1), ZnSO4 (40 kg.ha-1) and Control. During the experiment, some parameters such as the plant height and chlorophyll index were measured. At the end of the cultivation period, dry weight and Zn concentration of root, shoot and grain was determined using Atomic absorption apparatus (Perkin elmer A_Analyst 200 model). Likewise, content of soil available Zn was measured using DTPA. Results The amount of available zinc in all levels of iron oxide nanoparticles, except Amine iron oxide nanoparticles (at levels of 200 and 300 mg / kg), was significantly (p < 0.01) increased compared to control. The maximum amount of soil available Zn were observed in levels of 300, 200 and 100 mg.kg-1 Carboxyl iron oxide nanoparticles with 83.64, 70.91 and 63.64% increment compared to control, respectively. Effect of treatments of functionalized iron oxide nanoparticles and zinc sulfate on chlorophyll content, plant height and dry weight of shoots was significant (p < 0.01). The maximum yield of root and shoot was obtained at the level of 300 mg.kg-1 of Carboxyl iron oxide nanoparticles with 34.74 and 25.1% increment compared to control, respectively. The maximum grain yield was observed at the level of 300 mg.kg-1 of Carboxyl iron oxide nanoparticles with 36.51% increment compared to control. The maximum chlorophyll content was obtained in Carboxyl iron oxide nanoparticles (at level of 300 mg. kg-1) with 11.38% increment compared to control. The maximum of Zinc concentration in root, shoot and grain was observed at the level of 300 mg.kg-1 carboxylic oxide nanoparticles with 103.62, 159.26 and 26.87% increment compared to control, respectively. Conclusions The results showed that application of FIONPs improved soil pH and subsequently available zinc of soil. Also, nanoparticles increased the yield, concentration and uptake of zinc in root, shoots and grain of wheat. Therefore, based on the obtained results from this study, it can be said that use of new strategies such as nanoparticles can be useful in improving soil conditions and bioavailability of Micronutrient like Zinc and reducing chemical fertilizers.
Volume 42 - Issue 2
Soil Chemistry and Pollution
Hadi Habiby; Alireza Movahedi; Mojtaba Khoshravesh; Alireza Saberi
Abstract
Introduction Increasing the yield and, consequently, increasing the concentration of macro and micro nutrients in the plant is one of the important aspects of agriculture. The improvement of the quality and quantity of some elements, such as potassium, zinc, and iron in the soil can cause an increase ...
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Introduction Increasing the yield and, consequently, increasing the concentration of macro and micro nutrients in the plant is one of the important aspects of agriculture. The improvement of the quality and quantity of some elements, such as potassium, zinc, and iron in the soil can cause an increase in the yield of the crop and the concentration of these elements in plant tissues. The increase in the concentration of these elements in plants can be effective in the health of livestock and consequently the health of humans. One of the new approaches that can be used in this field is the use of magnetic water. Magnetic water is obtained by passing water from a magnetic field. An externally applied magnetic field causes changes in the atomic, molecular, and electronic structure of the treated water, such as changes to its solidifying and boiling points, viscosity and the dielectric constant, the formation of clustering structures from linear and ring hydrogen-bound chains of molecules, the magnetic interaction between these clustering structures, and increasing the polarization effects of water molecules. The biological effects of magnetic field or electromagnetic field treatments depend on the strength and exposure period of water conditioning, in particular, the ion content, quality, and the volume of water. Materials and Methods For this purpose, a field experiment was conducted in a factorial arrangement with two main treatments, adding and without adding potassium and zinc fertilizers, and five sub-treatments (magnetic field strengths, including a 0.4 Electromagnetic Coil (EC), 0.3 magnet, 0.3 EC, 0.1 EC, and the control treatment) in four replications at Research Station of Goran University of Agricultural and Natural Resources. The size of each experimental plot was 2 m × 2.5 m. Corn was planted in each plot with the distances of 15 cm from each other and rows with distances of 70 cm from each other. An electromagnetic coil and a permanent magnet were used to create a magnetic field. Water was passed from the middle of this magnetic field through a hose and the plots were irrigated with this magnetic water. The irrigation was conducted based on soil moisture content and continued until the harvest and drying of the plants. Soil and plant samples were taken at two flowering and harvesting stages and were transferred to the laboratory for analyzation. Concentrations of Zn and Fe in the soil and plant tissues were measured. Statistical analysis was performed using the SAS software. Results and Discussion The results of this study showed that all the plots that were irrigated by magnetic water had corn plants with greater height and more yield was obtained than the control treatments. This could be due to the ease of absorbing water from the soil. Magnetic water has lower surface tension than untreated water, so the plant needs less force to absorb water from soil particles. Also, the plants that were irrigated by magnetic water had higher concentrations (P <0.01) of elements such as zinc and iron in their cobs. Magnetic water can increase the availability of the elements in the soil. So, more concentration of elements can be absorbed by the roots and transferred to the aerial parts of the plants. Among the magnetic water treatments, 0.4 Tesla strength treatment had the highest effect on the yield and corn height, as well as zinc and iron concentration in cobs (P <0.01). Higher strengths of the magnetic field (0.4 T) had more effect on the availability of elements in the soil and their absorption by the plants. The yield of corn in 0.4 EC, 0.3 M, 0.3 EC, and 0.1 EC treatments that potassium and zinc fertilizers were added to them increased as compared to the control. So, increasing the strength of the magnetic field had more effects on some soil properties. The treatments that K and Zn fertilizers were added to them had more yield than other treatments that these fertilizers were not added to them. This could be attributed to the fact that magnetic water has increased the solubility of K and Zn fertilizers. In fact, magnetic water has been able to increase the uptake of Zn from the soil. Conclusion These results indicate that the magnetization of water can be used as an appropriate approach to increase the quantity and quality of product yield and the concentration of the elements in the crops.
Volume 40 - Issue 2
Plant Nutrition, Soil Fertility and Fertilizers
Esmaeil Dordipour; Zeinab Bastamikojour; Mojtaba Baranimotlagh; Abdolreza Gharanjiki; Mohsen Olamaee
Abstract
Introduction The most important constraint in maize crop yield in developing contries worldwide, and especially among resource-poor farmers, is soil infertility. Therefore, maintaining soil quality can reduce the problems of land degradation that decreases soil fertility and rapidly declining production ...
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Introduction The most important constraint in maize crop yield in developing contries worldwide, and especially among resource-poor farmers, is soil infertility. Therefore, maintaining soil quality can reduce the problems of land degradation that decreases soil fertility and rapidly declining production levels that occur in large parts of the world which needing the basic principles of good farming practice. For optimum plant growth, nutrients must be available in sufficient and balanced quantities. After nitrogen, phosphorus is the most limiting nutrient for crop yields, and is essential for maize growth and development. Large quantities of chemical fertilizers are used to replenish soil N and P, resulting in high costs and severe environmental contamination. Maize quantity and quality are increased by utilization of fertilizers, which has become the most important objective of these products worldwide. Phosphorus, is the second most important macronutrient required by the plants, next to nitrogen, and is reported to be a critical factor of many crop production systems due to its limited availability in soluble forms in the soils. The low availability of P to plants is because the vast majority of soil P is found in insoluble forms, and plants can only absorb P in two soluble forms, the monobasic (H2PO4-) and the dibasic (HPO42-) ions. Crop plants can therefore utilize only a fraction of applied phosphorus, which ultimately results in poor crop performance. To rectify this and to maintain soil fertility status, frequent application of chemical fertilizers is needed, though it is found to be a costly affair and also environmentally undesirable. Moreover, phosphorus (P) is an essential nutrientionl element for plant growth. Calcareous soils are frequently characterized by the low availability of P for plant uptake due to the low solubility of P compounds present in soils at high pH and the formation of relatively insoluble complexes, e.g., Ca-P. Many soils in Iran have received large amounts of P fertilizer and consequently contained a high level of available P. On the other hand, the root exudation of organic acids has been suggested to increase P availability in calcareous soils. The most common low-molecularweight organic acids (LMWOAs) identified in soils include oxalic, succinic, tartaric, fumaric, malic, and citric acids and are derived from the decomposition of soil organic matter in the upper soil horizons, microbial metabolites, canopy drip, and root exudation. The concentrations of organic acids in the rhizosphere or in soil solutions vary greatly and range from 10-2μM to over 80 mM. The ability of organic acids to release inorganic anions, such as P, has been reported and has been attributed to desorption of inorganic anions and solubilization of phosphate compounds. LMWOAs and their corresponding anions play a very important role to increase P bioavailability. Many studies have been conducted about the role of organic acids in increasing P availability, but these studies focused on acid soils in which Fe- or Al-bound P is the main P fraction. For calcareous soils where Ca-bound P is the main P fraction, questions that whether organic acids can mobilize P or not still exist. Although, a number of results show that addition of organic acids, especially citric and oxalic acids to soils can solubilize significant quantities of fixed P and reduce the sorption of newly applied fertilizer P. However, there are few studies on the transformations of P fractions induced by organic acids or organic anions, which are important for understanding the mobilization mechanisms of P and for exploring better ways of using different forms of P in soils. The objective of this study is to examine the effects of some organic acids and anions on the solubilization and plant uptake of soil P in some calcareous soils of Golestan province, Iran. Material and Methods For this purpose, a factorial pot experiment in a completely randomized design with three replications was conducted on maize. The first factor was comprised of 6 soil types from various areas of the province and the second factor was consisted of a combination of phosphorus fertilizer and organic acids (1) control, (2) 50 mg P kg-1, (3 and 4) 50 mmol kg-1 of organic acids (oxalic and malic acids), (5) P + oxalic acid and, (6) tomato fruit residue (25% w). After 10 weeks, plants were harvested and the parameters such as plant height, fresh and dry weights, phosphorus concentration and its uptake were determined. Results and Discussion Results indicated that soil type effect was statistically significant on the plant fresh and dry weights (P≤ 0.05), height, concentration and uptake of P (P≤ 0.01), respectively. Results also showed that the tomato fruit residue treatment in comparison with P fertilizer and malic acid treatments results in a significant increase in P taken up, and fresh and dry weights (P≤ 0.05). There was a significant difference between P fertilizer + oxalic acid and oxalic acid alone treatments in only plant height (P≤ 0.05). Also, no significant differences in terms of measured plant parameters were observed between malic acid and blank treatments (P≤ 0.05). Conclusion Application of tomato fruit residue rather than P fertilizer can help to take up residual soil P, to grow plants and to decrease of environmental pollution, and to be also affordable economically.
Volume 40 - Issue 1
M. Servati; M. Pishnamaz Ahmadi; H.R. Momtaz; M. Hassanlou
Volume 39 - Issue 2
H Masoudi; A Rohani
Volume 41 - Issue 2
Soil Genesis and Classification
Farideh Abbaszadeh Afshar
Abstract
Introduction Mapping the spatial distribution of soil taxonomic classes is important for informing soil use and management decisions. Digital soil mapping (DSM) can quantitatively predict the spatial distribution of soil taxonomic classes. DSM is the computer-assisted production of digital maps of soil ...
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Introduction Mapping the spatial distribution of soil taxonomic classes is important for informing soil use and management decisions. Digital soil mapping (DSM) can quantitatively predict the spatial distribution of soil taxonomic classes. DSM is the computer-assisted production of digital maps of soil type and soil properties. It typically implies use of mathematical and statistical models that combine information from soil observations with information contained in correlated variables and remote sensing images. Machine learning is a general term for a broad set of models used to discover patterns in data and to make predictions. Although machine learning is most often applied to large databases, it is an attractive tool for learning about and making spatial predictions of soil classes because knowledge about relationships between soil classes and environmental covariates is often poorly understood. Our objective was to compare multiple machine learning models (multinomial regression logistic, boosted regression trees and decision tree) for predicting soil great groups at Bam distinct in Kerman province.Materials and Methods The study area, Bam district was located between 58°4΄17˝ to 58°28΄8˝ E longitudes and 28°52΄51˝ to 29°9΄29˝ N latitudes (Fig. 1), at Kerman province, (Southeastern Iran). The area is surrounded by mountains (dominantly limestone and volcanic) from northwest toward southeast with major landforms included young alluvial fans and pediment, clay flat and hills. The mean annual precipitation, temperature and potential evapotranspiration are respectively 64 mm, 23.8◦C and 3000 mm with Aridic and Hyper thermic soil moisture and temperate regimes Stratified sampling scheme were defined in 100000 hectares, and 126 soil profiles were excavated and described by Key of soil taxonomy. Our objective was to perform and compare multiple machine learning models for predicting soil taxonomic classes (great group level). The models were used in this study including, multinomial logistic regression (MLR), boosted regression trees (BRT) and decision tree (DT). We used 80/20 training/testing split (80% of the pedon observations were used for model training and 20% for model testing). Kappa index (KI), overall accuracy (OC), Brier scores (BS), User accuracy (UA) and producer accuracy (PA) were used to compare model accuracy.Results and Discussion The profile description revealed the presence of two soil orders: Entisols and Aridisols that, subdivided in six suborders and eight great groups: Haplosalids, Haplocambids, Haplocalcids, Haplogypsids, Calcigypsids, Calciargids, Petrocalcids and Torriorthents. This testifies to the wide pedodiversity of the study area, considering that is characterized by the presence of eight soils great groups. Results showed that the geomorphology map contributed importantly to the prediction accuracy. This can be explained by the fact that the geomorphological surfaces have formed recently, or during a geological period with soil formation under conditions close to those of current processes in the arid regions. Terrain attributes and finally remote sensing indices after geomorphic surface were imported as predictors in the prediction. The best prediction result was obtained when characteristics derived from terrain, remote sensing and geomorphological processes were used together and when differentiation of geomorphological processes and overall heterogeneity identification and stratification of the study area was made. In areas where the distribution of predictors was more homogenous, the models can better understand and connect predictors and response. The spatial distribution of soils in the study area followed the distribution pattern of most geomorphological and terrain attributes. The results of model comparing indicated that decision tree was consistently the most accurate. The results of prediction accuracy of soil groups showed that the highest accuracy related Haplosalids, Calcigypsids and Petrocalcids soil great groups. The lowest of predictive quality was observed for Haplocalcids in three approaches. As a reliable and flexible approach, decision tree could be used successfully to prepare continuous digital soil maps.Conclusion The application of decision trees for prediction of soil types could be a promising alternative. In digital soil mapping, the best prediction result was obtained when parameters derived from terrain, remote sensing and geomorphological processes were used together and when differentiation of geomorphological processes and overall heterogeneity identification and stratification of the study area was made. In areas where the distribution of predictors was more homogenous, the models can better understand and connect predictors and response. Altogether, an extended digital terrain analysis approach and clear description of geomorphological, geological and pedological processes could be a promising key technology in future soil mapping.
Volume 42 - Issue 2
Plant Nutrition, Soil Fertility and Fertilizers
Hananeh Bahmaniyan; Habibollah Nadian Ghomsheh; Nafiseh Rang Zan
Abstract
Introduction With limited arable land available around the word, some ways can be used to increase the production per unit area to meet the increasing human need for food. In addition to quantity, consideration of quality of products can lead to improve communities’ health. So, in the last few ...
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Introduction With limited arable land available around the word, some ways can be used to increase the production per unit area to meet the increasing human need for food. In addition to quantity, consideration of quality of products can lead to improve communities’ health. So, in the last few decades, application of organic and bio fertilizers has been taken into account in order to increase quantity of products as well as their quality. Mycorrhiza fungi are the most abundant microorganisms in the soil and are considered as essential factor in sustainable soil-plant system. The use of existing organic and inorganic fertilizers may stimulate the Mycorrhiza-plant root symbiosis and ensure the supply of nutrients to the plant for sustainable production. Filtercake is a main byproduct of sugarcane industry which is obtain during the processing of sugarcane syrup. Filtercake can be transformed into the valuable source of nutrients by biodegradation processes. Many studies have suggested that the use of fertilizers along with Mycorrhiza, especially phosphorous fertilizers, has negative effects on fungi symbiosis with plant root. Regarding this issue, the question arises that due to richness of Filtercake of organic matter, nutrients and microorganisms, is the Mycorrhiza interdependency affected by the addition of this organic manure to the soil? In order to answer this question, the present study was conducted to investigatethe interaction effect of Mycorrhiza(Glomus Intraradices)andFiltercake on coriander (Coriandrum Sativum L.) production. Materials and Methods In order to study the interaction effect of Filtercake and Mycorrhiza on the coriander production, a pot experiment was conducted in factorial completely randomized design with consideration of Mycorrhiza fungi (Glomus Intraradices) treatments at two levels of non-inoculation (m1) and inoculation with Mycorrhiza (m2), Filtercake in three levels of zero (f1), 1.5 (f2) and 3 wt.% (f3) with coriander (Coriandrum sativum L.) as experimental plant in 4 replicates in the greenhouse of Agricultural Sciences and Natural Resources University of Khuzestan during 2017-2018. Twelve weeks after sowing plants were harvested and considered parameters were measured. Data analysis was performed using SAS. Comparison of the meanings was performed using Duncan's test at 5% level. Excel were used to draw charts and graphs. Results and Discussion The highest plant height and root length were observed in treatment consist of Mycorrhiza and 3% Filtercake. Same trend was observed in case of aboveground (cilantro) and root dry weight. The presence of organic matter, increasing of quasi-hormonal activity and improvement of physical, chemical and biological properties of soil are among the factors that provide favorable conditions for vegetative growth and, as a result, increase plant yield. The application of Mycorrhiza increases concentrations of phosphorus, potassium, calcium and magnesium in cilantro, at about 103, 40, 16 and 12 percent, respectively, which are about 11, 105 and 31 percent in case of iron, zinc and copper. Mycorrhiza has a positive effect on the nutrients content in plant, which can be attributed to increased absorption through the fungal hyphae and also to the enrichment of the plant's rhizosphere. The concentration of nutrients in cilantro was significantly increased due to increase in Filtercake level. Since most of the nutrients in the soil are immobilized, the addition of Mycorrhiza fungi can help to improve nutrient uptake by increasing the volume of root access and stimulating the mineralization processes. Application of Filtercake along with Mycorrhiza improves the biological status of the fungi. Increasing the level of the Filtercake from 0 to 3 percent increases colonized Root length, Mycorrhiza interdependency and colonization percent by 51, 22 and 28 percent, respectively. According to the results, the use of Filtercake not only does not reduce the Mycorrhiza indices, but also increases them and act as a key factor for encouraging symbiosis of fungi and plant, so contribute to the enhancement of plant growth parameters. Conclusion In most of the studied characteristics, the maximum amount were observed in the treatment containing 3% Filtercake and Mycorrhiza. So, the simultaneous application of Filtercake and Mycorrhiza increased the growth parameters of the coriander. Although both of treatments (Filtercake and Mycorrhiza) have been effective in increasing the concentration of essential elements in aboveground part of plant, the effect of Mycorrhiza on increasing the concentration of phosphorus and zinc is greater than its effect on other elements, which is for iron and copper in case of Filtercake. The use of organic manure, such as Filtercake, even with high nutrient content, cannot affect the Mycorrhiza interdependency and other colonization indices due to the low release rate of these elements into the soil environment. It seems that the combination of Mycorrhiza and Filtercake by increasing the microbial and enzymatic activities in the soil and the separate application of Mycorrhiza and Filtercake by improving the access ability of the nutrients leads to provide better growth of the plant.
Volume 38 - Issue 2
H. Nematpour Malikabad; M. j. Sheikhdavoodi; I. Khorasani Frdvany; H. Zaki Dizaji
Volume 39 - Issue 1
M. A. Delavar; A. Naderi
Abstract
Introduction Generally, formation and development of sodic soils often appear as almost large in flat plains capable of cultivation, especially in arid and semi-arid regions. Due to their unsuitable characteristics, Slickspots leave bad effects on plants growth and finally on human health. High levels ...
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Introduction Generally, formation and development of sodic soils often appear as almost large in flat plains capable of cultivation, especially in arid and semi-arid regions. Due to their unsuitable characteristics, Slickspots leave bad effects on plants growth and finally on human health. High levels of soluble and exchangeable sodium ions and colloidal material are the main marks of sodic soils. Different surface areas of Slickspot are spread over the flat and arable plains in Iran. The aim of this study was to evaluate the different properties of sodic soils and related soil formation factors in the semi-arid soils of Abyek plain. Materials and Methods The study area, with the coordinates 35° 47′ - 35° 53′ N and 50° 31′ - 50° 33′ E, was located in the southeastern of Abyek city, Ghazvin providence. Piedmont plain was the main physiography of the area and altitudes were divided in three topographic zones: 1190-1180, 1170-1160, 1150-1140 meters above sea level that the zones were classified into upper, middle and flat parts, respectively. Based on topography and site properties, 13 soil profiles were excavated in the topographic zones and all profiles were described based on USDA Standard Soil Description Manual Results and Discussion The results showed that soil acidity measured in saturated extraction ranged from 8.6 to 9.1, 9.8 to 9.7 and 9.1 to 10.1 for upper, middle and flat areas, respectively. Field observation studies of upper parts revealed that gravelly and subangular blocky soil structures were found in surface and subsurface horizons, respectively, while the subangular blocky and massive structures were found in subsurface horizons of middle parts profiles. The subangular blocky and columnar structures were demonstrated structures in profiles of the flat areas. Despite the low topography difference, 5 to 10 m in upper lands, exchangeable sodium content and electrical conductivity were low, and saline or sodic soils were not observed. These soils were classified as Xeric Haplocambids. In the middle part with 2 to 5 m difference in elevation, soils were classified as Sodic Xeric Haplocambids and Sodic Xeric Haplocalcids. The white spots observed in the sodic soils were classified as Xeric and Vertic Natrargids. Compare with the adjacent areas, the concentration of carbonate and bicarbonate anions were relatively high in soils of the flat areas that led to considerable increase in soil acidity. This can shows the accumulation of sodium carbonate salts in the soils. The presence of carbonate and bicarbonate anions in middle areas, probably was due to the development of Sodicization in the soils. The XRD diffractometers showed illite, montmorilonite, chlorite and palygorskite as the clay minerals in soil heorizons. Illite was found in all soil horizons of flat areas with deep decline. This decline was along with increasing of smectite clay minerals in Natric horizons that had poor drainage conditions. The clay coatings in the natric horizons were confirmed by micromorphology and scanning electron microscopy techniques. The cumulative clays on external surfaces of soil aggregates and wall pores, in flat areas, revealed the clay eluviation process. Because of the high soluble and exchangeable sodium cations, the conditions were favorable for transfer of clay in the soils, even in the presence of lime. Conclusion Consequently, the main soil formation factors in sodic soils can be presented as different in soil positions on piedmont physiography, the local relief, lateral and vertical movement of water and soluble salts from neighboring areas into the downstream lands and also salt and sodium containing minerals deposited by wind. The Slickspots and related soils were one of the major terrestrial phenomena in the plain Abyek. The Sodic soils in the plain were formed in the absence of high ground water table. Other environmental factors such as micro reliefs, position on the Landform, lateral movement of water and soluble salts and windborne sediments, played and essential role in the formation of sodic soils. The results of the experiments indicated that Sodicization process is developing towards the adjacent land and the absence of gypsum accelerated this development in these areas. Also, mineralogical studies indicate the presence of smectite mineral clay in Natric horizon where the drainage condition was poor and gave the possibility of neoformation of smectite, and that clay movement evidence from upper parts of profile was confirmed by micromorphological studies.
Volume 42 - Issue 1
Soil Genesis and Classification
samaneh Tajik; shamsollah ayoubi; mohmmad mehdi darvisihi; hossein khademi
Abstract
Introduction Soil snails constitute an important part of the forest ecosystem and play an essential role in litter decomposition and soil calcium concentration. Snails are known as bioindicators because of narrow distribution, short lifetime, and high sensitivity (22, 24). The abundance and distribution ...
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Introduction Soil snails constitute an important part of the forest ecosystem and play an essential role in litter decomposition and soil calcium concentration. Snails are known as bioindicators because of narrow distribution, short lifetime, and high sensitivity (22, 24). The abundance and distribution of soil snails are dependent on different environmental conditions, such as precipitation, pH, soil calcium, and plant cover. Also, soil properties are mainly related to topographic parameters. Because ecosystem components have complex relationships, we need powerful models to find effective factors and spatial variations of the soil fauna (23). Linear Regression and random forest are popular and applicable models in soil science. Up to the present, no study has investigated the effect of soil parameters on snail abundance using linear regression and random forest. This study was performed to investigate the effect of soil properties and topographic parameters on the abundance of soil snails and their distribution in a part of forest area located in Bahramnia forest, an experimental site in Golestan Province, in the north of Iran. Materials and Methods This study was conducted in Shast Kalate (Bahramnia) forest, an experimental forest of Gorgan University of Agricultural Sciences and Natural Resources, located at the eastern Caspian region, north of Iran (36° 43′ 27″ N latitudes, 54°24′ 57″ E longitudes). 153 soil samples were collected from 0-10 cm; then soil snails were gathered and classified into the Gastropoda taxonomic class group. Soil properties, such as Soil particle size distribution (clay, silt, and sand), soil pH, electrical conductivity (EC), calcium carbonate equivalent (CCE), soil organic carbon (OC), total nitrogen (TN), and Soil microbial respiration (Resp), were measured via laboratory analysis. Also, digital elevation model and satellite images were used to determine the topographic parameters, such as Elevation, slope, slope aspect (Aspect), land surface temperature (land temp) wetness index (WI) and normalized difference vegetation index (NDVI). We used linear regression and nonlinear random forest models for investigating linear and nonlinear relationships between soil properties, topographic parameters, and the abundance of soil snails. Likewise, sensitive analysis was done to find the importance of the input parameters. Results and Discussion The PCA analysis showed that first and second components explain 38 and 21 percent of the variation. In the first component, EC, OC, TN, pH, and silt were the most variable, and in the second component CCE, Clay, OC, sand, and EC were the most important parameters. In both components, topographic parameters had no effect. The PCA graph showed that CCE, sand, and pH had the most correlation with snail abundance and EC, Resp, OC, and TN affected their abundance. The validation results of regression and random forest models showed that random forests have more accuracy (0.49) and low error (1.82). In addition, the sensitive analysis showed that CCE, pH, EC, OC, aspects, elevation, and land temp are the most important parameters on snail abundance. Different studies reported that pH and CCE are effective parameters on snail abundance (20, 17). Also, Ondina., et al. (27) reported that EC has an important effect on soil snail abundance. We hypothesize that topographic parameters affect soil snail nonlinearly and by affecting soil properties. Aspect is one of the topographic parameters that, via an effect on land temperature, land cover, and pH (8), has an important role in soil snails. In this way, elevation, by affecting pH, wetness, land temperature, OC, and TN, affects soil snail abundance (13). Land temperature is the other topographic parameter that is affected by aspect and elevation and had a significant effect on snail abundance by affecting OC and wetness (17). Conclusion Based on the results, nonlinear random forest model had more accuracy than linear regression in predicting snail abundance. Results showed that calcium carbonate equivalent, pH, EC, and organic carbon were the most effective soil priorities on snail abundance. There was no linear relation between soil properties and soil snails, but in the nonlinear model, we found their role. Aspect, elevation, and land temperature were the most effective parameters on snail abundance that probably affected soil properties, such as calcium carbonate and soil moisture.
Volume 40 - Issue 2
Precision Agriculture
Mojtaba Naderi-Boldaji; Abbas Hemmat; T. Keller
Abstract
Introduction Soil compaction is a serious concern in modern agriculture. Field traffic using machines with high axle loads is likely to compact the soil below the plough layer. Compaction of the subsoil should be avoided since soil productivity is at risk of being reduced, and because the effects are ...
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Introduction Soil compaction is a serious concern in modern agriculture. Field traffic using machines with high axle loads is likely to compact the soil below the plough layer. Compaction of the subsoil should be avoided since soil productivity is at risk of being reduced, and because the effects are very persistent, perhaps even permanent. Precompression stress is widely applied as a border between elastic and plastic soil deformations under stress application. As long as the stress does not exceed the precompression stress, soil deformation is expected to be recoverable after the removal of stress (i.e. passage of the tire). The precompression stress is conventionally determined using the standard procedure of Casagrande from the log stress – void ratio curve resulting from confined uniaxial compression of intact soil samples taken at the field. With advances in the technology of precision agriculture, site specific management of machinery traffic is under focus by researchers. Field mapping of soil precompression stress would allow for site specific modifying the machine parameters (e.g. the tire inflation pressure) to control the applied stress below the precompression stress. For example, where the soil moisture is high, a decrease in tire inflation pressure increases the soil-tire contact area and thus decreases the severity of stress propagation in soil. However, the conventional method of estimating the precompression stress is time-consuming, labor intensive thus not suitable for mapping applications. Horizontal penetrometer is a popular device for on-the-go measuring of soil strength. Horizontal penetrometer resistance is an attractive measurement because it is relatively simple, fast and cheap, can be carried out on-the-go, thus yielding spatial information with a high resolution. A multi-tip horizontal penetrometer would also allow for discrete-depth measuring the soil strength. As penetrometer resistance and precompression stress are both measures of soil strength, it was hypothesized that they are highly correlated. Therefore, the relationship between precompression stress (σpc) and horizontal penetrometer resistance (PR) was investigated in a wide range of soil textures. This would suggest an alternative for on-the-go measurement of σpc for field mapping and site-specific management of soil trafficability. Materials and Methods Field measurements were conducted in different soil textures in Switzerland. The clay content of the soils varied from 189 to 584 g kg-1. Horizontal penetrometer resistance was measured at 0.25 m depth at a traveling speed of 0.25 m s-1. Cylindrical core samples were taken at the local minima and maxima of PR along the transects. Cone index measurements were also performed to a depth of 0.5 m at the points of core samples. The samples were subjected to stepwise compression stresses by an Oedometer and the resulting deformation was recorded. The void ratio was calculated with particle density and bulk density at the end of each stress step. The precompression stress was estimated at the point of maximum curvature of log stress- void ratio with fitting Gompertz function. Correlation and regression analyses were performed in SAS software. Results and Discussion The results showed that the Gompertz function explains well the void ratio versus log of stress for different soil textures. The Gompertz parameters were characterized with respect to soil physical characteristics. Precompression stress decreased with increasing soil moisture, soil clay and organic matter content. A relatively strong correlation was found between σpc and PR (R2= 0.47, RMSE= 15.4 kPa) which was significantly improved (R2= 0.59, RMSE= 13.7 kPa) with the effect of soil water content. The high scatter of the relationship between precompression stress and horizontal penetrometer resistance was discussed to be likely due to the difference between the soil failure mechanisms around a penetrating tip and under uniaxial compression. A comparison of different compaction tests (e.g. semi-confined and plate sinkage) with PR may suggest stronger correlations. A strong correlation (R2= 0.6) was also found between PR and cone index (CI). CI was found to be larger than PR for all the soils. Conclusion It was concluded that the soil compaction characteristic (log stress versus void ratio) is strongly governed by the soil initial void ratio with an increase of precompression stress with decreasing the initial void ratio. In the range of variations tested, the relationship between PR and σpc was not affected by soil texture (clay content). The study suggests that measurement of PR can be a fast alternative for mapping of soil precompression stress by compensating for the effect of soil moisture (by e.g. a dielectric sensor). therefore, a combined horizontal penetrometer needs to be employed.
Volume 40 - Issue 1
N. Nasirian
Volume 45 - Issue 1
Naser Rashidi; Abdolamir Moezzi; Afrasyab Rahnama
Abstract
Introduction Salinity is one of the growth-limiting factors for pistachio (Pistacia vera L.) crop production in semiarid and arid soils of Iran. Salinity poses two major threats to plant growth: osmotic stress and ionic stress. In addition, it also manifested an oxidative stress. The deleterious effects ...
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Introduction Salinity is one of the growth-limiting factors for pistachio (Pistacia vera L.) crop production in semiarid and arid soils of Iran. Salinity poses two major threats to plant growth: osmotic stress and ionic stress. In addition, it also manifested an oxidative stress. The deleterious effects of salinity affect different physiological and metabolic processes of plants. The uptake of high amounts of salt by the plant leads to the increase of the osmotic pressure in the cytosol. Under this condition compatible osmoprotectant, such as proline and soluble sugars, is produced to protect the cells against the adverse effects from salt stress. High accumulation of proline is associated with tolerance to stress. Na+ and K+ homeostasis plays a vital role in the growth and development of higher plants under salt conditions owing to potassium–sodium (K+–Na+) interaction and is often associated with K+ deficiency. Application of potassium fertilizer affect plants growth and tolerance under salinity stress. The potassium is indispensable for several physiological processes, including the maintenance of membrane potential and turgor, enzyme activation, stomatal movement, regulation of osmotic pressure. Therefore the objective of this study was to evaluate the effect of potassium sulfate fertilizer application on growth, photosynthetic pigments, proline, soluble sugar and Na and K Uptake by Badami-riz Zarand P. vera L. (the main pistachio rootstock in Iran’s pistachio plantation area) seedlings under salinity stress. Materials and methods This study carried out in greenhouse condition as a factorial experiment based on a completely randomized design and in three replications. Experimental factors was salinity of irrigation water (in three levels including 0.65, 5 and 10 dS m-1) and potassium sulfate fertilizer application )in three levels including without application or control, 150 and 250 mg kg-1 soil). Pistachio (Pistacia vera L. cv. Badami-riz Zarand) seeds were surface sterilized with solution of sodium hypochlorite in distilled water. Seedlings were transplanted in plastic potscontaining 10 kg of soil. The pots were maintained in the greenhouse under 25 ± 4 ◦C temperature and under natural light. The mean relative humidity was 40 %. At the end of growth period (six mounth), the plants were harvested and leaf area, root dry weight, shoot dry weight, chlorophyll a and b, total chlorophyll, carotenoids, proline, spluble sugar, root and shoot K and Na concentration were measured. In addition, the K and Na uptake in shoot and root, as well as K/Na ratio were calculated. Analysis of variance (ANOVA) was performed using SAS program version 9.4 (SAS Institute, Cary, NC). Significant differences of the mean values (P <0 .05 for F-test) were determined by Duncans’s Multiple Range Test. Results and Discussion Results indicated that with increasing salinity stress, leaf area, root, and shoot dry weight, chlorophyll content and shoot and root K uptake decreased, while carotenoids and shoot and root Na concentration increased. The highest and lowest value of leaf area, root, and shoot dry weight, chlorophyll content and shoot and root K uptake were observed in control and high salinity levels (10 dS m-1) treatments respectively. Application of potassium sulfate fertilizer at both levels (150 and 250 mg kg-1) led to a significant increase in leaf area (8.1 and 8.7 % respectively), root dry weight (21.2 and 20.0 %), shoot dry weight (21.3 and 19.9 %), total chlorophyll (10 and 7.8 %), carotenoids (32.2 % and 35.7), proline (21.1 and 14.4 %), root K concentration (44.1 and 56.2 %), shoot K concentration (11.0 and 26.9 %) and K uptake in root and shoot. in high salinity treatment seedlings showed higher Na+/K+ ratio in the roots than that of the shoots. In addition, application of potassium sulfate fertilizer decreased Na uptake in shoot and root. Moreover, the addition of potassium fertilizer increased K/Na ratio in the shoot and root. The results also indicated there were no significant difference between potassium sulfate fertilizer levels (150 and 250 mg kg-1) effects on investigated traits. Conclusion It could be concluded that application of potassium sulfate fertilizer results in reduce the negative effects of salinity stress and subsequently enhance tolerance to salinity stress and improved P. vera L. seedlings growth. Therefore, nutrient management of potassium can be considered for decline of negative effects of salinity in P. vera L. v. Badami-riz Zarand seedlings.
Volume 45 - Issue 1
Reza Khodadadi; REZA GHORBANINASRABADI
Abstract
Introduction Streptomyces is the most important and dominant genus of actinomycetales with more than 664 species which some of its species may stimulate plant growth through nutritional and physiological mechanisms that include: dissolution of phosphates, production of siderophores and phytohormones, ...
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Introduction Streptomyces is the most important and dominant genus of actinomycetales with more than 664 species which some of its species may stimulate plant growth through nutritional and physiological mechanisms that include: dissolution of phosphates, production of siderophores and phytohormones, biological Nitrogen fixation and production of antifungal metabolites. Silicon has significant positive effects on improving the growth and physiological characteristics of the plant by improving the root system, biosynthesis of phytohormones, resistance to biological and non-biological stresses and nutrient uptake. Improvement of the silicon concentration in the plant depends on its availability in soil. Soil application of resources with appropriate amount of silicon is of great importance in increasing the availability and uptake of silicon. It is also documented that the co-application of plant growth promoting bacteria and silicon is a useful and efficient method to increase plant growth and yield under normal and stress conditions. Due to beneficial effects of plant growth promoting bacteria and silicon in improving crop growth and also the importance of soil application of different silicon sources, the aim of this study was to Investigate the effect of Streptomyces isolate, silicon application using calcium-magnesium silicate source and the combined application of Streptomyces + silicon on growth parameters, chlorophyll content and accumulation of some nutrients in soybean (Glycine max L.)Materials and Methods A pot experiment was designed as factorial in a complete randomized design with 3 replications under natural light and temperature conditions. Experimental treatments included soil application of calcium-magnesium silicate source (37.9% silicon dioxide) at four levels 0 (M1), 200 (M2), 400 (M3) and 600 (M4) kg Si ha-1 and two levels of inoculation with Streptomyces isolates (no inoculation (B0) and inoculation with Streptomyces (B1). Surface-sterilized seeds were inoculated with a suspension of (107 CFU mL-1) Streptomyces isolate. The effect of experimental treatments on plant development stage (late vegetative growth period) was investigated. The soybean plants were harvested after 10 weeks of growth period from soil surface. Plant growth parameters including shoot and root biomass, root volume and plant height were determined. Also, chlorophyll content (a, b, Total) and concentration of nitrogen, silicon, phosphorus and potassium in the shoot were measured.Results and Discussion The results of the present study showed a positive and significant effect of the co- application of silicon and Streptomyces inoculation on improvement of the growth characteristics and chlorophyll content compared to their separate application. The highest amounts of shoot biomass (19.3 g per pot), root biomass (7.6 g per pot), root volume (38.07 cm3), plant height (98 cm) and chlorophyll a (18.07 mg / g), chlorophyll b (14.4 mg / g) and total chlorophyll (32.4 mg / g) were measured in the co-application of 600 kgha-1 Si (M4) and Streptomyces inoculation (M4B). .Our results showed the improvement of soybean growth parameters could be due to the positive effect of Streptomyces isolate on plant growth promotion and utilization of calcium-magnesium silicate in soil. Combined application of silicon and Streptomyces inoculation increased the concentration of silicon, nitrogen, phosphorus and potassium in the M4B treatment compared with the lonely application of highest level of silicon source (M4) by 16.25, 7.45, 45.6, 51.7%, respectively.Conclusion Based on the results of the present study soil application of calcium-magnesium silicate increased plant growth and physiological factors. Streptomyces inoculation improved the effects of calcium-magnesium silicate levels to enhance growth parameters, chlorophyll content and nutrient concentration (silicon, nitrogen, phosphorus and potassium) in soybeans. This study was carried out in pot experiment at the vegetative growth stage of soybean. Therefore, supplementary studies are necessary in field and harvest stage.Keywords: Streptomyces, inoculation, silicon, soybean, plant growth
Volume 45 - Issue 1
hossein haji agha-alizade; behnam sepehr
Abstract
In the modern era, population growth has led to an increase in many related issues. One of these is the causes related to agriculture. In recent years, the use of planting techniques that can properly prepare the seedbed and sow the seeds at an almost uniform depth, has become more necessary than ever. ...
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In the modern era, population growth has led to an increase in many related issues. One of these is the causes related to agriculture. In recent years, the use of planting techniques that can properly prepare the seedbed and sow the seeds at an almost uniform depth, has become more necessary than ever. SolidWorks software was used to design this car. Statistical data were analyzed using IBM SPSS software. Cultivation on raised bed is one of the most modern cultivation methods in the world. In this type of cultivation, without any tillage operations and directly, all cultivation stages are done in one stage. The device was built in six rows. In order to investigate six types of planters for growing chickpeas (representative of coarse-grained) and rapeseed (representative of fine-grained), an experiment was conducted using strip plots in a completely randomized block design with four replications in the 2021-2022 crop year. Soil moisture content, soil texture and soil temperature were extracted before planting. The parameters measured in this plan were: fracture percentage, planting depth, uniform distribution and seed fall and seed germination percentage. The machine was built with a working width of 1.5 meters, a length of 1.5 meters and a height of 2.3 meters. The construction of this car was done in the industrial complex of Barzegar Machine in Hamedan city. Type of planter in six levels b1: V-shaped, b2: U-shaped, b3: T- inverse, b4: Two-plate V-shaped, b5: cross-shaped and b6: Tulip-shaped were tested. The main purpose of this study is to build a device with a suitable planting arrangement for direct sowing machines in Iran (modeled on growers from other countries), to develop technical knowledge of the application of some planting methods, to eliminate the traditional methods of the past, Instantaneous monitoring of planting machine performance as well as increasing farmers' confidence in using planting machines to grow fine-grained crops. SolidWorks2021 software was used to design this machine. Statistical data were analyzed using IBM SPSS 25 software. The device was built in six rows. In order to evaluate six types of planters for growing chickpeas and rapeseed, an experiment was conducted using strip plots in a completely randomized block design with four replications in the crop year 1399-1400. The parameters measured in this plan were: fracture percentage, planting depth, uniform distribution and seed fall and seed germination percentage. The construction of this car was done in the industrial. Complex of Barzegar Machine in Hamadan. The type of planter was tested in six levels: b1: v-shaped, b2: u-shaped, b3: inverted t, b4: two-plate v-shaped, b5: cross-shaped and b6: tulip-shaped. The general purpose of this study is to build a device with suitable planting arrangement for direct sowing machines in Iran. The results showed that the crusader has a significant advantage over the other operators in the studied four parameters at the level of 5%.The general review of the research results showed that the crusader has a significant advantage over the other operators in the studied four parameters at the level of 5%. Compared to the other five types of crushers and in relation to the highest numbers obtained from the treatments, cross-planting increased the uniformity coefficient of planting depth by 7%, uniformity of seed longitudinal distances by 23% and germination percentage by 2.3% compared to other Has been planted. The percentage of seed breakage decreased by changing the distribution from cast iron to plastic oblique by 1.25%. These results show the superior design and distribution mechanism, planters and different settings of the machine in the cultivation of coarse and fine grain crops. Increasing the growth rate did not have a significant effect on the parameters of fracture percentage, uniformity coefficient of planting depth and coefficient of uniformity of seed longitudinal distances. However, it has significantly reduced the green percentage. The overall results showed that a cross-planter with a diagonal plastic distribution and a telescopic fall tube is more suitable for sowing coarse seeds. The mentioned planters are not suitable for small seeds. In general, with the results and relationships obtained from the research, it was possible to monitor planting operations and receive feedback on the improper operation of the machine in agricultural fields. The results and coefficients of explanation of the field test were weaker than the laboratory results. Compared to the other five types of crushers and in relation to the highest numbers obtained from the treatments, cross-sowing increases the uniformity coefficient of planting depth by 7%, uniformity of seed longitudinal distances by 23% and germination percentage by 2.3% compared to other planters.
Volume 45 - Issue 1
Fatemeh Samie; Nafiseh Yaghmaeian Mahabadi; Sepideh Abrishamkesh; Ataolah Maslahatjou
Abstract
Introduction Soil is one of the important parts of ecosystem. Land use change and developed agriculture can lead to soil loss and land degradation because they have damaging effects on soil properties including soil organic carbon, aggregate stability and soil erodibility factor. Soil erodibility factor ...
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Introduction Soil is one of the important parts of ecosystem. Land use change and developed agriculture can lead to soil loss and land degradation because they have damaging effects on soil properties including soil organic carbon, aggregate stability and soil erodibility factor. Soil erodibility factor can be measured by different methods including experimental plots. It shows that the problem should be dealt directly and it demands high amount of cost and time. The factor can be calculated by soil properties such as soil organic matter and particle size distribution. They play a crucial role for sustainable ecosystem and decreased soil erosion. Since a few decades ago, deforestation has caused increased soil degradation and it has had devastative effects on soil surface and subsurface properties. This study investigated soil erodibility factor by different methods in three land uses including forest, grassland, and cropland at two depths in Sidasht of Guilan province. Soil quality index was calculated for evaluation of effects of land use on soil quality degradation.Materials and Methods The study area is located in Tootkabon in Guilan province (latitude 36º 50' 10" N, longitude 49º 39' 15" E). Parent material is limestone and geomorphologic units that are comprised of hill land and plateau. The soil moisture and temperature regimes are xeric and thermic, respectively. In order to reach the goals of the study, samples were collected from three land uses of forest, grassland, and cropland at two depths of 0 to 10 and 10 to 20 cm in regards to parent material, slope class, and equal slope aspect. Soil samples were prepared in two categories: the disturbed soil and the undisturbed ones. After becoming air drying, the disturbed samples were sieved by a 2 mm sieve. Soil properties such as soil texture, bulk density, soil organic carbon, CaCO3, and soil stability were measured. Soil erodibility factor is calculated by nomograph, Vaezi and Ostovari methods. Also sensitivity index and stratification ratio were taken into account. Soil quality index was determined using linear and nonlinear scoring methods based on minimum data set. All soil parameters were tested using one-way analysis of variance and the differences among means were analyzed using Duncan's significant difference test at the probability level of 0.05.Results and Discussion Results showed that the effects of land use and soil depth on bulk density, soil texture and soil erodibility factor using nomograph method were non-significant (p ≤ 0.05). The amount of organic matter, soil structure stability index and soil erodibility factor of Vaezi method were significantly decreased by increasing the depth. MWD and GMD at forest were higher than cropland, and CaCO3 and soil erodibility factor of Ostovari method at forest were lower than cropland. In comparison with other methods, soil erodibility factor of Ostovari method demonstrated that the effect of land use was significant (p ≤ 0.05). Soil properties including bulk density, MWD, organic matter, and soil erodibility factor of Ostovari method were selected as the minimum data set. Results of nonlinear scoring method were better than linear scoring method because the linear scoring method just showed the effects of soil depth on soil quality index (p ≤ 0.05). The soil quality index using linear scoring method was decreased by increasing the depth. However, soil quality index using nonlinear scoring method in forest was higher than cropland, and it was decreased by increasing the soil depth. It was found that non linear scoring methods are superior to linear and soil quality index using the nonlinear scoring method showed better the soil quality among different land uses.Conclusion Sensitivity index and stratification ratio values showed that land use change and soil depth effect on soil properties including CaCO3, organic matter, structure stability index and MWD. The stratification ratio values more than 1.5 for organic matter and soil structure stability index can be stated that these properties can show the degradation of soil quality due to land use change. Soil quality evaluation showed that in relation to the effect of land use on soil quality index, nonlinear scoring method is superior to linear scoring, so that forest and agricultural land use had the highest and lowest soil quality index by nonlinear scoring method, respectively. Therefore, due to the high sensitivity of soil quality to land use change, preventing land use change is one of the necessary measures for sustainable soil management in the study area.
Volume 45 - Issue 1
Ataallah Khademalrasoul; Hadi Amerikhah
Abstract
Introduction Climate is one of the most effective factors on soil formation, evolution and degradation. It is include different parameters which mainly based on precipitation and temperature. In the recent years the effects of global warming and climate change has extremely enhanced. Climate change as ...
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Introduction Climate is one of the most effective factors on soil formation, evolution and degradation. It is include different parameters which mainly based on precipitation and temperature. In the recent years the effects of global warming and climate change has extremely enhanced. Climate change as an important phenomenon is effective on precipitation parameters including volume, intensity and concentration which categorized in the temporal and spatial variations. Quantifying the effects of climate change is important for identifying critical regions prone to soil erosion under a changing environment. Land-based ecosystems are influenced by patterns of air temperature and precipitation, which include daily and seasonal changes along with humidity and wind, and the nature of the land surface. Global climate change already has observable effects on the environment. Regarding the importance and effectiveness of climate factor and climate changes during the time, it is essential to focus on climate changes on water behavior at different scales. Indeed, precipitation parameters interacting the soil parameters are influencing on runoff potential in the fields and watersheds. In this regard Rainfall-runoff erosivity (R) is one key climate factor that controls water erosion. Universal soil loss equation (USLE) is the main common equation to predict soil loss, this equation consisting 5 factors which R-Factor (Rainfall erosivity factor) is one of the effective factors in this equation. Material and Methods Regarding the effect of climate on soil erosion processes therefore, monitoring of climate is really important. In this study in order to evaluate the climate changes based on time series, four climatological stations including, Ardal, Saman, Izeh, and Dehdez were selected. Using the statistical data of precipitation, calculation of eroding index was performed until 2017. The ACF (Auto Correlation Function) and PACF (Partial Auto Correlation Function) for precipitation data were prepared, afterwards the ADF test was performed at confidence level of 1, 5 and 10 percentage. Then the suitable parameters for p, r and q were selected and the SARIMA (Seasonal auto-regressive integrated moving average) model was provided. The statistical analyses were performed with Stata SE, Minitab 18 and SPSS 19. Moreover, the graphical trends of rainfall as an index of precipitation and the rainfall erosivity factor (R-Factor) were presented. Also, the spatial distribution of R-Factor (in the form of GIS-Maps) were provided including three separated maps based on real data, 5 year predicted and 10 year predicted data. So there was a possibility to monitor and compare the spatial distribution of R-Factor at different time periods. Then based on the area, the percentage of rainfall erosivity index was calculated for the study area based on the real data, 5 year predicted and 10 year predicted data. In addition, the statistical parameters including R-square, RMSE, P-value and so on were calculated for the best model (SAR12) regarding all climatological stations. Results and discussion Our results depicted that to present the trend of precipitation variations as erosive factor the ARIMA (0,0,1)×(1,1,1)12 was the best model. Also, the seasonal autoregressive moving average showed the variation of precipitation in the study area which located in the southwest of Iran. The results of modeling stated that reduction of precipitation for 5 and 10 year periods after 2017. According to amount of monthly simulated of precipitation, the amount of erodibility index was obtained in the area which illustrated the declining trend until 10 year. According to ADF test for all evaluated climatological stations the probability for Ardal was 0.34, for Dehdez was 0.425, for Saman was 0.345 and for Izeh was 0.177, therefore there was difference between climatological stations. Furthermore, the statistical analyses for SAR12 model revealed that the R-square for Ardal station was 0.492, for Dehdez was 0.716, for Saman was 0651 and for Izeh was 0.576. Moreover, approximately 37 % of area has very low rate of erodibility index without previous occurrence. Conclusion Our results clearly confirmed the importance of climate factors and climate change during the time. As results illustrated regarding the variations of precipitation the R-Factor changed. Moreover, climate change is effective on spatial variations of crop cover in the watersheds. Climate change is capable to alter the crop cover patterns in the watersheds and the changes in crop cover distribution and runoff could change the soil erosion potential. Generally, based on results has to focus on water resources conservation in the study area to preserve soil and water against erosive forces and try to improve the vegetation cover because of decreasing of precipitation. In order to manage the soil resources, we need to monitor the climate changes in the watersheds and try to enhance the vegetation covers in the critical parts on the fields.
Volume 45 - Issue 1
Mohammad Adib; Nafiseh Rang Zan; Amir Naserin
Abstract
Introduction The highest amount of water consumption is allocated to the agricultural sector, which has led to a water crisis due to increasing demand for food production and non-conservative agriculture and climate change in some countries. Sugarcane needs a lot of water during the growing season and ...
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Introduction The highest amount of water consumption is allocated to the agricultural sector, which has led to a water crisis due to increasing demand for food production and non-conservative agriculture and climate change in some countries. Sugarcane needs a lot of water during the growing season and is sensitive to drought. In drought conditions and water stress, the intensity of reverse flow of water to the soil surface increases and can cause salinization of the soil around the roots of sugarcane, which is a relatively sensitive plant related to salinity. Due to the high-water consumption in sugarcane fields and also the shortage and decline of water quality in dry years, this study aimed to investigate the effect of conventional and deficit irrigation by variable and fixed alternate furrow irrigation on soil salinity and some nutrient concentration consist of phosphorous and potassium in sugarcane field. Materials and Methods To investigate the effect of irrigation methods on salinity distribution and concentration of phosphorous and potassium in soil, this experiment was conducted with independent variables of irrigation method treatment including conventional (complete) irrigation, variable alternate furrow irrigation and fixed alternate furrow irrigation, irrigation round treatment including before irrigation, after one and two times irrigation, sampling location treatment including bottom, middle and top of raised bed and sampling position treatment consist of start, middle and end of furrow. The experiment was performed factorially in a completely randomized design with three replications in sugarcane fields of MianAb in Susa. Statistical analysis was performed using SPSS software and mean comparisons were performed by Duncan's multiple range test. Charts were drawn using Excel software.Results and Discussion The results showed that irrigation method is mainly affects salinity distribution and concentration of phosphorus in soil. The fixed alternate furrow irrigation method had the greatest effect on soil salinity changes and reduced the salinity as compared to the conventional method and the variable alternate furrow irrigation. In general, in the conventional irrigation method (complete irrigation of all furrows) and variable alternate furrow irrigation, there is no constantly dry furrow as compared to the fixed alternate furrow irrigation method, and this intensifies the accumulation of salts on the sides and the top of raise beds. Increasing the frequency of irrigation (irrigation round) reduces the soil salinity so that in soil samples before irrigation, soil salinity was 2.30 dS/m and with one round irrigation, this amount decreased by 7.8% to 2.12 dS/m and with two rounds of irrigation reached to 2.09 dS/m. In terms of locative variation of salinity related to the fixed alternate furrow irrigation method, the lowest amount of salinity was observed in the bottom of the raised bed. With increasing distance from the beginning of furrow, an upward trend in soil salinity was reported. Regarding the change in the amount of available phosphorus in the soil under the influence of irrigation method, any of the deficit irrigation methods can be used as an alternative to conventional irrigation. The highest amount of soil phosphorus was reported in the middle of the raise bed. Soil potassium changes were not directly affected by irrigation method and the highest amount was assessed in the bottom of the raise bed. In terms of salinity, the lowest value was at the bottom of the furrows and the highest value was at the top of the raise bed. Unlike salinity changes, soil phosphorus had the highest accumulation in the middle of the raise bed and reached a minimum at the top of the raise bed. A relatively uniform trend was observed in changes in soil phosphorus from the beginning to the end of the furrow. Contrary to salinity changes, the highest amount of available potassium in soil was observed in the bottom of raise bed and a decreasing trend in soil potassium was reported from the beginning to the end of furrow. In general, based on the results, the average level of soil salinity and potassium and the highest amount of phosphorus were reported in the middle of the raise bed.Conclusion For optimal water use and soil salinity management, application of deficit irrigation methods especially fixed alternate furrow irrigation instead of conventional irrigation method, is recommended. In case of salinity and concentration of mentioned nutrients, the top of the raise bed in all three irrigation methods, would not be a suitable place for plant cultivation.
Volume 46 - Issue 1
Soil Physics, Erosion and Conservation
Heidar Ghafari; Hadi Ameri khah
Abstract
Introduction: The processes of soil erosion and sediment transport along rivers are the main causes of some socio-economic and environmental problems, such as a reduction in water quality, storage capacity of dams, destruction of aquatic habitats, failure of hydroelectric power plants, and soil degradation. ...
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Introduction: The processes of soil erosion and sediment transport along rivers are the main causes of some socio-economic and environmental problems, such as a reduction in water quality, storage capacity of dams, destruction of aquatic habitats, failure of hydroelectric power plants, and soil degradation. Therefore, understanding the sedimentation status of watersheds is crucial for the effective management of soil and water resources. However, due to the lack of technical and human resources, continuous recording of sediment data is not possible in most sediment measuring stations, and sediment data are recorded only for a few days. In such a situation, a model that can estimate the amount of sediment load using auxiliary variables such as stream discharge and rainfall becomes crucial. Today, it is believed that techniques based on artificial intelligence have a much greater ability to uncover hidden relationships between variables than classical methods and are thus very useful and effective in modeling natural processes.Materials and methods: In this study, various machine learning techniques, including Artificial Neural Network (ANN), Adaptive Fuzzy-Neural Inference System (ANFIS), and Random Forest (RF), were used for sediment load modeling and sediment forecast for days without measurements. To achieve the research objectives, long-term meteorological and hydrometric data ranging from 2000 to 2020 were collected from related organizations and pre-processed before entering the model. The input variables for the models included 24-hour rainfall, flow rate, normalized difference vegetation index, maximum and minimum temperature, and daily suspended sediment as the dependent variable. Prior to modeling, the entire dataset was divided into two parts, training and testing, in a 70:30 ratio. Relationship modeling was performed using the training data, and model validation was conducted using the test dataset. The efficiency of the models was evaluated using two indicators, the coefficient of explanation (R2) and the root mean square error (RMSE). Additionally, morphometric parameters such as form factor (FF), drainage density (DF) coefficient, and relief ratio (RR) were utilized in modeling.Results and discussion: The hydrological analysis of the basin revealed that the highest annual amount of rainfall and erosivity index were recorded at the Sheyvand station in the east of the basin, while the lowest values were observed at the Ramhormoz station. The highest average monthly flow rate of 5.8 cubic meters per second was obtained at the Manjeniq station in April, and at the Mashin station, the highest average monthly flow rate of 8.8 cubic meters per second was recorded in December and January. Morphometrically, the studied basin belonged to the class of elongated basins, sloping basins in terms of relief, and the medium class in terms of drainage density. Analysis of the time series of NDVI index showed that the highest vegetation cover occurred in March, while the lowest values were recorded in September and October. The annual trend of the vegetation index indicated an overall improvement in vegetation cover in the region from 2000 to 2020, with the NDVI value increasing from 0.15 to 0.22.Among the different machine learning techniques studied, the Artificial Neural Network (ANN) model had the highest coefficient of explanation (R2=0.87) and the lowest RMSE for both sediment measuring stations in the region, making it the best model. The optimal inputs for the neural network model at Mashin station were daily average flow adjusted by the basin shape factor, daily rainfall, last day's rainfall, daily minimum temperature and daily maximum temperature. For the Manjeniq station, the optimal inputs were daily average flow, daily rainfall, last day's rainfall, cumulative rainfall for the past two days, and cumulative rainfall for the past three days. The NDVI index was removed from the model due to its low significance. The Random Forest (RF) model ranked second, and the Adaptive Fuzzy-Neural Inference System (ANFIS) model ranked third, with weak performance, especially for the Mashin station, where out-of-range errors occurred.Temporal analysis of sediment values showed that the highest sediment production occurred in December and January for Mashin station and in April for Manjeniq station. The highest production of sediment occurred in 2006 and 2002, and the trend of changes from 2011 to 2018 showed a decline, attributed to consecutive droughts and lack of rainfall. The annual average sediment production calculated using the values estimated with the neural network model was 88017 tons, equivalent to 1 ton per hectare per year. Conclusion: Overall, this research demonstrated that machine learning methods, especially the neural network model, are highly effective for modeling and predicting sediment on a daily scale. These methods can compensate for the lack of sediment measuring facilities and equipment in most existing hydrometric stations in the country and eliminate the need for continuous sediment data and other water quality parameters.
Volume 45 - Issue 2
mona daghlavi; Mahmoud Ghasemi Nejad Raeini; Naim Loveimi; amin lotfi jalal-abadi
Abstract
Introduction Achieve more production, efforts should be made to increase yield per hectare. One of the things that play an important role in increasing crop production, disease control, chastity control, improving soil fertility and structure is the implementation of proper crop rotation. Crop rotation ...
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Introduction Achieve more production, efforts should be made to increase yield per hectare. One of the things that play an important role in increasing crop production, disease control, chastity control, improving soil fertility and structure is the implementation of proper crop rotation. Crop rotation increases the efficiency of production and yield through the continuity of soil vegetation, more efficient water use, preservation of soil nutrients, increase of soil organic matter and stability of soil grains, reduction of pests and diseases, and better control of weeds. Also, data collection in the conducted research is done in a traditional way, which is usually difficult, limited and very time-consuming due to the dispersion of farms and their size. Materials and Methods His study was conducted to investigate the effect of crop rotations on wheat yield using satellite images in three crop years 2017-2018, 2019-2028, 2019-2020 in the fields of Shavor region of Khuzestan province. In this research, all the evaluated images are related to the Sentinel-2 satellite and all these images were obtained from the US Geological Survey website. The satellite images were taken at the flowering stage of wheat, and images without clouds and fog were used on February 25, 2019 (for the year before rotation) and February 19, 2021 (for the year after rotation). Also, for pre-processing and processing and extracting information, SNAP software, Sen2Cor and ENVI plugin were used, respectively. The steps of this research were done in three steps. In the first stage, five plant spectral indices EVI, GNDVI, GARI, NDVI and RVI were evaluated to identify the best index to estimate wheat yield. The spectral index, which has a higher correlation with the yield of wheat, was chosen as the base index and was used to continue the research. In the second stage, three farms were randomly selected from each rotation to evaluate wheat yield after their application. In this section, variance analysis was performed in the form of a completely random design in three replications (one replication for each farm). The treatments include four alternations of wheat-wheat-wheat, wheat-canola-wheat, wheat-rice-wheat and wheat-clover-wheat. At this stage, the comparison of means was done by Duncan's multi-range test and in the MSTATC software environment. The third stage is the changes in wheat yield in each rotation in two times before and after applying that rotation. For this purpose, the changes of the base spectral index before and after the application of periodicity were set as criteria. Results The results of variance analysis of five spectral indices studied in this research showed that the coefficient of explanation of each of these indices with wheat yield at the time of flowering is NDVI with 76, RVI with 73, GARI with 71, EVI with 60 and GNDVI with 57 respectively. In this research, the NDVI spectral index has the highest correlation, R2 of 76%, and the minimum error, RMSE of 0.547 earned the results showed that the average and the dispersion coefficient of the NDVI spectral index of intervals have a significant difference at the probability level of 1%. So that in terms of the average, the lowest average of the NDVI spectral index is in wheat-rice-wheat rotation with a rate of 0.2650 and the highest average is in the wheat-clover-wheat rotation with a rate of 0.5603. According to the distribution coefficient, the minimum and maximum values belonged to the rotation of wheat-canola-wheat with the rate of 0.0505 and wheat-rice-wheat with the rate of 0.1970. The results of the corresponding comparison before and after the application of each rotation showed that not observing the rotation and wheat cultivation after two crop years led to a 10% decrease and the use of rice in the crop rotation led to a 50% decrease in the NDVI spectral index. Also, the use of rapeseed and clover in crop rotations has led to an increase of 2 and 30% in NDVI spectral index compared to before rotation. The results of the dispersion coefficient of the NDVI spectral index in the time before and after the application of rotation showed that in the continuous cultivation of wheat, the dispersion coefficient due to the decrease in yield uniformity in different parts of the field led to an increase of 27% and in the rotation of wheat-rice-wheat it led to an increase of 152 became a percentage However, the distribution coefficient of wheat-canola-wheat rotation and wheat-clover-wheat rotation resulted in a decrease of 57 and 32%, respectively, due to the increase in yield uniformity in different parts of the field.Conclusion Heat is one of the strategic products, and the evaluation of different rotations is of particular importance in increasing its yield. In this research, five plant spectral indices EVI, GNDVI, GARI, NDVI and RVI were investigated in order to identify the base index for wheat yield estimation. The results of the analysis of these indices showed that the NDVI spectral index with an explanation coefficient of 76% has the highest correlation with wheat yield. The comparison results of the NDVI spectral index correspondingly in each rotation in two states before and after the rotation showed that the continuous cultivation of wheat in an agricultural land after two crop years led to a 10% decrease in the NDVI spectral index and the use of rice in the wheat-rice rotation. - Wheat leads to a 50% decrease in the NDVI spectral index of wheat; But the use of canola and clover in the rotation of wheat-canola-wheat and wheat-clover-wheat led to an increase of 2% and 30% of NDVI spectral index, respectively. Also, the results of the comparison of the dispersion coefficient of the NDVI spectral index before and after the application of rotation showed that in the continuous cultivation of wheat, the dispersion coefficient increased by 27% due to the decrease in yield uniformity in different parts of the field, and in the wheat-rice-wheat rotation, the dispersion coefficient also as a result of the reduction of yield uniformity in different parts of the farm, it led to an increase of 152%.
Volume 45 - Issue 3
Parisa Khajeh; Mina Taghizadeh
Abstract
Introduction Sansevieria trifasciata is a perennial plant from the liliaceae family, which originates from tropical and semi-tropical regions of the world. Sansevieria trifasciata variateis are one of the most popular ornamental indoor plants due to having types with striped leaves. Today, conventional ...
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Introduction Sansevieria trifasciata is a perennial plant from the liliaceae family, which originates from tropical and semi-tropical regions of the world. Sansevieria trifasciata variateis are one of the most popular ornamental indoor plants due to having types with striped leaves. Today, conventional propagation methods are not adequate to meet the marketable requests of Sansevieria trifasciata due to the slow growth of cutting. So, it is conceivable to use rooting and growth stimulator agents. This study aimed to investigate the effects of arbuscular mycorrhiza and biochar application on some morphophysiological parameters in Sansevieria trifasciata var. cuttings.Materials and Methods This research was conducted in the greenhouse of the faculty of agriculture and environmental science of Arak University with controlled conditions of 25 ◦C, 70% humidity and 10,000 lux of light. The effect of biochar application (5 and 10%) and arbuscular mycorrhizal fungi (Glomus etunicatum, Glomus intraradices, Glomus mossea) (6 and 12%) was investigated on propagation and growth of Sansevieria trifaciata var. Laurentii and Sansevieria trifaciata var. Moonshine cutting. The experiment was conducted as factorial an in a completely randomized design at three replicates. The leaf cutting with V-shape end were keep on the lab condition for two days to callus initiation of wound surface. Subsequiently, healed cutting were cultured in pots that were containing cocopeat-perlite and different treatments of arbuscular mycorrhiza and biochar. Morphological and physiological traits were measuremed after 8 months of cultivation, which were included rooting and bud stimulation time, roots number and length, length of the longest root, buds number, length, anddiameter, the amount of cutting rot, the number of leaves, the size of callus based on the rating of 1 to 3, fresh weight (FW) of roots and leaves, the dry weight (DW) of roots and leaves, relative water content (RWC), electrolyte leakage, chlorophyll pigment. Arbuscular mycorrhizal root colonization was determinded by grid-line intersect method. Results and Discussion The results showed that the application of 10% biochar in culture bed had an increasing effect on leaf number, root biomass percentage, root colonization percentage and leaf dry weight in both cultivars but also caused to increase the decay rate of the cuttings of these two cultivars. Application of 6% arbuscular mycorrhizal fingi increased the number of buds, root colonization and bud motivation time, and led to decrease leaf biomass and cuttings rot percentage. The root colonization decreased at lower application level of arbuscular mycorrhizal fungi and biochar. The maximum root colonization (80%) was observed in the culture medium with 10% biochar and 12% arbuscular mycorrhiza. The application of the arbuscular mycorrhizal fungi in the medium of Sansevieria trifaciata cuttings directed to an increase in the biomass compared to the control. The amount of leaf electrolyte leakage of leaf was higher (28.37%) by application of 10% biochar in the culture bed compared with the cuttings treated with 5% biochar and control. Plants from the cuttings grown in the bed containing 10% biochar and 6% mycorrhizal inoculum had the highest number of leaves (2.83). It was approximately two folds compared to the control. The leaf electrolyte leakage was higher (28.37%) than the plants obtained from the cuttings treated with 5% biochar and control by application of 10% biochar. The total chlorophyll content of the leaf in both cultivars increased significantly with the application of different concentrations of biochar compared to the control. Biochar application influenced on microbial biomass through altering the soil porosity, soil moisture and temperature. Also, biochar stimulated plant growth through the positive effects on microbial population. These results suggested that the applications of biochar at an appropriate proportion could change plant growth and microbial community.Conclusion Biochar and arbuscular mycorrhizal fungi by establishing a symbiotic relationship between fungus and root, stimulated rooting growth. These treatments were able to root in different cultivars of Sansevieria trifaciata propagation. Root colonization of arbuscular mycorrhizal fungi was depended on the variety of plant. The applied treatments showed more impact on morphological and physiological traits in Sansevieria trifaciata var. Moonshine than that in Sansevieria trifaciata var. Laurentii cultivar. The rotting of Sansevieria trifaciata var. Laurentii cuttings was more than that of the Sansevieria trifaciata var. Moonshine. The best treatment for Sansevieria trifaciata variateis cuttings was application of 5% biochar and 6% arbuscular mycorrhiza and cultured in cocopeat-perlite bed.
Volume 45 - Issue 3
Mahmoud Baghbanian; shaban ghavami jolandan; Seyed Mohammad Safieddin Ardebili; Seyed Majid Sajadiye
Abstract
Introduction In recent years, Underground heating systems are one of the cleanest and best types of heating systems which these techniques have been used in many greenhouses. In this method, a source of thermal energy, which is often a gas or diesel, is used to heat the fluid. Then, the heated fluid ...
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Introduction In recent years, Underground heating systems are one of the cleanest and best types of heating systems which these techniques have been used in many greenhouses. In this method, a source of thermal energy, which is often a gas or diesel, is used to heat the fluid. Then, the heated fluid is transferred to the entire greenhouse through the pipe networks that are placed on the floor of the greenhouses and under the soil, and creates a pleasant heat. During the cold months of the year, having a proper heating system for the greenhouse is essential. A standard greenhouse heating system could improve the temperature inside the greenhouse and spread it evenly on the entire surface of the greenhouse and finally, it is very effective in the growth and quality of plants and products in all months of the year. Today, fluids play a very important role in industry, especially in heating systems. Common fluids such as water, ethylene glycol and motor oil have a limited conductivity coefficient. Therefore, using the above-mentioned fluids at high temperatures causes heat transfer problems. Nanofluids consist of very small particles (usually less than 400 nm) dispersed in a base fluid. The conducted research shows that due to the high thermal conductivity of nanofluids compared to common fluids, in the future nanofluids will become a new type of fluid used in advanced heat transfer for engineering applications. Therefore, according to the importance of this topic, in this research, the heating system of the greenhouse floor is simulated and analyzed using CFD technique.Materials and Methods In this research, in order to simplify the process of simulation, the inhomogeneity in the fluid flow is ignored and the single-phase flow is considered. In order to investigate the effect of each of the nanofluids on the fluid behavior and heat transfer of the pyramidal greenhouse, analysis and simulation of the greenhouse was performed based on three-dimensional computational fluid dynamics. First, the geometry of the control volume of a greenhouse was designed in Solidwork software, and in order to check the simulation, a pyramidal geometry was considered. The boundary conditions for the coldest day and night temperature in the year were extracted according to the environmental conditions by measuring the data of temperature, humidity and air flow. Two parameters of pressure drop value and Nusselt number were selected as target parameters in this research. The flow friction coefficient in the floor heating section was calculated through the pressure drop along the section and its hydraulic diameter. Single-phase fluid pressure drop in all pipes inside the thermal cycle was modeled in this section. Finally, the parametric analysis of the results and the comparison of the heating efficiency of the greenhouse floor for two types of nanofluid alumina and titanium dioxide in volume percentages of 1%, 2% and 3% were used. Besides, the effect of the mentioned parameters on the Nusselt number and in the flow of floor heating was investigated.Results and DiscussionBased on the obtained results, it was concluded that an increase in Reynolds number in all volume percentages leads to an increase in Nusselt number and alumina nanofluid has a higher Nusselt number than titanium dioxide nanofluid. Also, in both nanofluids assuming a constant inlet temperature of 40℃ and a diameter of nanoparticles of 5 nm, the Nusselt number also increased with an increase in the volume percentage of particles at a constant Reynolds number. According to the results obtained with the increase in the diameter of nanoparticles, the Nusselt number decreased for both alumina and titanium dioxide nanofluids, which is greater for titanium dioxide nanofluids. Considering the findings related to the pressure drop, with the increase in the volume percentage of nanoparticles in both nanofluids, the pressure drop increased, and this drop is more severe in the alumina nanofluid, and it could be attributed to the higher density and viscosity of the alumina nanofluid compared to the titanium dioxide nanofluid. The results related to the pressure drop showed that, with the increase in the volume percentage of nanoparticles in both nanofluids, the pressure drop increased, and this drop is more intense in the alumina nanofluid and this factor is attributed to the higher density and viscosity of alumina nanofluid compared to titanium dioxide nanofluid. On the other hand, the increase in Reynolds number in both nanofluids has resulted in an increase in pressure drop. The results related to the changes in the friction coefficient in terms of Reynolds number in different volume percentages show that the coefficient decreases with the increase in Reynolds number, and these changes are more intense at lower Reynolds numbers. By comparing the performance coefficient between alumina nanofluid and titanium dioxide nanofluid, it can be concluded that the average value of this coefficient is 14% higher than other nanofluids for alumina nanofluid. But, the sensitivity of the performance coefficient of titanium dioxide nanofluid compared to alumina nanofluid is more intense to the changes of Reynolds number.Conclusion Due to the production of greenhouse products in all seasons and the necessity of precise greenhouse control, it can be concluded that dealing with new and advanced methods in the management and optimization of the country's greenhouses is importance. The results of the present research show the fact that the simulation of heating from the greenhouse floor and its various aspects can be a suitable measure to check the uniformity and proper distribution of heat inside the greenhouse. In order to improve the efficiency of thermal equipment, using nanofluids with higher thermal ability is essential. Besides, comparing the performance coefficient of the system due to the use of nanofluids indicated the high efficiency of the use of nanofluids in comparison with pure water in the greenhouse floor heating system.
Volume 46 - Issue 3
Soil Genesis and Classification
Mozhdeh Taghipour; Nafiseh Yaghmaeian Mahabadi; Mahmoud Shabanpour
Abstract
Introduction: Soil quality index is used as a quantitative tool for assessing the impact of land use and management practices on soil condition. Soil quality is a sensitive indicator for revealing the dynamics of soil conditions, and it may vary with different land use and ecological restoration measures. ...
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Introduction: Soil quality index is used as a quantitative tool for assessing the impact of land use and management practices on soil condition. Soil quality is a sensitive indicator for revealing the dynamics of soil conditions, and it may vary with different land use and ecological restoration measures. The land use affects the physical and chemical properties, biological processes, and land productivity, which lead to the change in soil quality. Land use change and agricultural development can lead to degradation, erosion and reduction of surface and subsurface soil quality. In most of the conducted studies, the surface soil quality has been evaluated; but these studies provide incomplete information because subsurface soil have the greatest impact on soil function and crop. In spite of various soil quality assessment methods developed in former researches, there are fewer attempts for selecting suitable and sensitive soil quality index, especially in different land uses. In this study, soil quality indicators were evaluated using multivariate analysis in three different land uses to select the most suitable and appropriate soil quality index in Tootkabon area of Guilan province.Materials and Methods: The study area is located in Tootkabon in Guilan province (latitude 36º 53' 21" N, longitude 49º 33' 44" E). Parent material is limestone and geomorphologic units that are comprised of hill land and plateau. In order to achieve the objectives of the research, 20 composite soil samples were taken from two depths of 0 to 15 and 15 to 30 cm from each of the land use, including forest, cropland and rangeland (60 soil samples in total) with the same parent material. The three land uses were located next to each other and at a close distance. In this research, using the principal component analysis (PCA) method, among 12 physical, chemical and biological soil indicators as total data set (TDS), clay percent, mean weight diameter, organic matter and available phosphorus were determined as the minimum data set. Then, the soil quality was evaluated by integrated quality index (IQI) and Nemoro quality index (NQI) using two linear and non-linear scoring methods (LS and NLS) and two soil indicator selection approaches, a total data set (TDS) and a minimum data set (MDS). Finally, to prioritize the soil quality indices based on sensitivity index (SI) and efficiency ratio (ER), the ranks of both criteria were summed and then made appropriate decision. All soil parameters were tested using one-way analysis of variance and the differences among means were analyzed using Duncan's significant difference test at the probability level of 0.05.Results and Discussion: The results of the present study showed that some soil properties including clay percentage, mean weight diameter, organic matter and available phosphorus had the greatest effect on soil quality in the study area. Most of the soil properties in rangeland and forest had a higher stratification ratio compared to cropland. The soil quality indices calculated using linear function for MDS indicated soil quality of forest and cropland were higher than rangeland. Maximum SI belonged to IQI-LS-TDS and IQI-LS-MDS with values of 1.56 and 1.40, respectively. Efficiency ratios (ER) were calculated to specify the power of each soil quality index being as representative index for whole soil parameters set. IQI-LS-MDS and IQI-NLS-MDS have the highest value of ER (75.0 %), it is obviously deducted that these developed soil quality indices correlate with much indicators than other indices. It has more efficiency ratio and therefore represents the soil overall condition highly. Finally prioritizing according to ranks of SI and ER showed that IQI-LS-MDS is the most suitable approach in soil quality assessment of study area. Conclusion: Minimum data set selection using principal component analysis as a multivariate statistical method could adequately represent total data set method. Therefore, it seems to be an appropriate approach for choosing more effective indicators with respect to saving time and money in the developing countries The linear soil quality indices showed higher capability than non-linear indices to differentiate soil quality among different land uses. Overall results of the prioritization soil quality indices imply that the IQI-LS-MDS has the most efficiency and sensitivity for variation in land uses, so it is suggested to use this quality index for further and comprehensive soil quality assessments plans.
Volume 45 - Issue 3
Alireza Abdollahpour; Mojtaba Baranimotlagh; Amir Bostani; Farshad Kiani; Farhad Khormali; REZA GHORBANINASRABADI
Abstract
Introduction Globally, deforestation is the dominant land use change process and has severe effects on soil biogeochemical properties. Large areas of the north facing slopes of the Alborz mountain range in northern Iran are covered by extensive loess deposits. Loess often contain little clay results ...
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Introduction Globally, deforestation is the dominant land use change process and has severe effects on soil biogeochemical properties. Large areas of the north facing slopes of the Alborz mountain range in northern Iran are covered by extensive loess deposits. Loess often contain little clay results in a loss of SOC under cultivation. Deforestation and cultivation on the loess hillslopes in northern Iran have resulted in a deterioration of soil quality, particularly significant reduction in SOC. Loess lands of Golestan province in northern Iran is densely being cultivated following deforestation. Labile fractions of soil organic matter (SOM), rather than total SOM, have been used as sensitive indicators of soils' quality and response to agricultural management changes. Several physical, chemical, and biological methods have been used to distinguish between labile (or biologically active) and recalcitrant pools of SOM. So, this research aims to investigate the effect of land use change from pristine and undisturbed forest as a reference to other land uses on soil organic carbon components and fractions as an important indicator in the sustainable soil management system and maintaining fertility and controlling soil erosion. Also, the effect of these land use changes on total carbon, soil organic carbon, and finally on the physical and chemical components of soil organic carbon.Materials and Methods The study area is the Toshan watershed, which is located in the northwest of the city of Gorgan (Golestan province) in the north of Iran. Four major and dominant types of land use were considered in the study area, including a) garden (olive), b) agricultural (cotton), c) virgin or untouched forest, d) abandoned (raspberry). Soil carbon fractionation was done by two physical methods (soil aggregate fractionation method) and chemical method (hydrolysis of organic matter with hot water). The selection of soils in different land uses was such that they have similar initial conditions and therefore the change in soil carbon in each use is related to the change in land use. The obtained data were analyzed based on the factorial design in the form of completely randomized design and using SAS software.Results and Discussion The results showed that the highest amount of total carbon and soil organic carbon was observed in the forest treatment and in the first depth (6.02% and 3.5%, respectively), which had a significant difference compared to other land use treatments studied. The results showed that despite the absence of a significant difference between the two depths, the amount of stable organic carbon increased with increasing soil depth in agricultural and abandoned uses. The forest land use had the highest amount of stable organic carbon at the depth of 0-10 cm at the rate of 2.51%, followed by garden treatment at the same depth. The lowest amount of stable organic carbon was recorded in the abandoned land use treatment. The highest amount of organic carbon dissolved in water at both investigated depths was obtained in the forest management treatments and then in the abandoned management. While no significant difference was observed between the two investigated depths in the abandoned land use. A significant decrease in organic carbon fractions that can be extracted with hot water was observed in abandoned and agricultural uses, as well as their increase in forest land uses. After the forest land use, the olive garden land use had the highest amount of total and organic carbon, however, there was no significant difference between the agricultural and abandoned treatments. In forest and garden treatments, the amount of stable carbon at a depth of 0-10 cm is significantly higher than the amount of stable organic carbon at a depth of 10-20 cm. In the garden use treatment, the amount of organic carbon in the soil at a depth of 10-20 cm showed a significant increase of 35% compared to the first depth.Conclusion A significant decrease in organic carbon fractions that can be extracted with hot water was observed in abandoned and agricultural uses, as well as their increase in forest uses. In total, the results showed that the carbon of labile fraction was more responsive to the type of land use than other fractions, and among the different methods of carbon fractionation, physical methods showed a clearer response to land use change.
Volume 46 - Issue 3
Energy and Renewable Energies
Ahmadreza Abdollahpour; Reza Tabatabaee; Jafar Hashemi
Abstract
Introduction: Agricultural residues and wastes are the main source of biomass for use in bioenergy production and animal and poultry feed production industries. These biomasses in their original form have a large volume and low energy (per unit volume) and require a lot of space and extensive movement. ...
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Introduction: Agricultural residues and wastes are the main source of biomass for use in bioenergy production and animal and poultry feed production industries. These biomasses in their original form have a large volume and low energy (per unit volume) and require a lot of space and extensive movement. Therefore, one of the methods of optimal use of these biomasses is to transform them into pellets, which have more mass and energy per unit volume and enable their easier use and transportation. Currently, biomass has the fourth place in energy supply after oil, natural gas and coal and provides approximately 14% of the world's energy needs. The use of biomass, especially in European Union countries, as an attractive source for replacing fossil fuels is developing and expanding. The use of biomass as fuel has significantly reduced the amount of environmental pollutants, so that the amount of CO2 absorbed from the atmosphere during biomass growth is similar to the amount produced during combustion, followed by a net cycle of production. Materials and Methods: The raw materials for making pellets were prepared from spruce wood sawdust (collected from a sawmill in Sari) as well as corn stalk and soybean residues in the fields of Dasht Naz in Sari. The desired materials were transferred to the laboratory in the necessary amount and kept at ambient temperature until the experiments. The samples were first crushed into 20 mm sizes and then powdered using a grain mill (Mehr Tehiz company, Iran) and passed through 18 mesh sieves in the range of 1 mm to make pellets. A palletization mechanism was used to compress the pellet. This system was designed and built in biosystem mechanics of Sari University of Agricultural Sciences and Natural Resources. The material was placed inside a steel mold with a cylinder inner diameter of 8.05 mm and a height of 150 mm with a blocked end. A piston with a diameter of 8 mm connected to the driving arm of the tension-compression test machine was used to compress the material. Loading by a piston with a quasi-static speed of 5 mm per minute is compressed to a pressure of 1300 N.Results and Discussion: In this research, the mechanical and thermal properties of pellets made from the combination of spruce sawdust and corn and soybean residues were evaluated. In the present study, the effect of four combinations of agricultural and forest materials at two moisture levels (12% and 18% based on fresh weight) on the indices of density, compressibility, Hausner ratio, strength and calorific value of the produced pellets were investigated and evaluated. it placed. The results showed that the pellet density at 18% humidity was lower than the density at 12% humidity. The highest density related to the combination of 60% spruce wood sawdust-40% corn stalks was obtained with a value of about 149 kg/m3 and the lowest value related to 100% soybean stalks was about 110 kg/m3. Also, the ratio of Hanser and CI in the combined pellets that have a higher percentage of sawdust and also in the combination of sawdust with corn stalks are within the permissible range. The highest pellet strength was 23.8 N/cm corresponding to 100% sawdust at 18% humidity and the lowest was 15.4 N/cm corresponding to 100% soybean stalk at 12% humidity. The calorific value of the pellets is in the range of 14.37 to 18.52 MJ/kg, which is the minimum value for the pellet made from 100% soybean stalk at 18% humidity and the maximum value for the pellet made from 100% fir wood sawdust and It was obtained at a humidity of 12%. Therefore, the use of agricultural wastes and their proper combination is a good option for the production of biofuels due to their density and strength.Conclusion: The type of biological waste and moisture percentage affect the physical and mechanical properties of the produced pellets. In general, the combination of spruce wood sawdust with corn stalks and soybean improved the mechanical and thermal properties of the pellet. Hanser's ratio and compressibility in the combined pellets that have a higher percentage of sawdust and also in the combination of sawdust with corn stalks are within the standard range. Also, in the compositions that have a higher proportion of spruce wood sawdust and lower moisture, the density and strength factors of the pellet increase. The highest and lowest calorific values were obtained in a higher ratio of sawdust and a higher ratio of corn, respectively. Therefore, it is possible to make pellets from the waste of garden and agricultural products that have good density and strength and high calorific value.
Volume 45 - Issue 3
F. Zandian; amin farnia; M Sheikholeslami; A. Rezaizad
Abstract
Introduction Chitosan is a biological polymer that is obtained from the chitin of crustaceans, fungi and Arthropoda, and is the most abundant polysaccharide on the earth's surface after cellulose (5). According to some evidences that indicate the improvement of the quality of plant products by chitosan, ...
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Introduction Chitosan is a biological polymer that is obtained from the chitin of crustaceans, fungi and Arthropoda, and is the most abundant polysaccharide on the earth's surface after cellulose (5). According to some evidences that indicate the improvement of the quality of plant products by chitosan, studying and understanding the effect of chitosan bio stimulant spraying on the quantitative and qualitative performance of important plants such as tomatoes has particular importance in agricultural research.Materials and Methods was done in order to investigate the effect of chitosan bio stimulant on the growth and yield and some quality characteristics of tomato fruit in a factorial format based on a randomized complete block design with three replications in two crop years 2017-2018 in fields belonging to Dasht Sabz Company, Kasht Complex and the RoginTak industry located in the Iran, Kermanshah. In this experiment, the chitosan bio stimulant was evaluated at five levels (control(S0), 1/1000(S1), 2/1000(S2), 3/1000(S3), and Seed coating(K) treatment). The experiment included 15 plots, each plot with a length of 4.2 meters and a width of 2.1 meters. Three rows were planted in each plot and 7 plants in each row and 21 plants in each plot. The distance between the rows was 1.4 meters and the distance on the row was 30 cm. In total, 315 plants were cultivated in this experiment. The planting density was about 2.38 plants per square meter or 23800 plants per hectare. Analysis of total data was collected using MSTAT-C statistical software Results and Discussion The results of analysis of variance showed that the effect of chitosan spraying on all studied traits was significant, the highest yield was obtained in the S3 treatment in the second year with the amount of 227tons per hectare. Chitosan spraying in the first and second year increased the yield compared to the treatment. It was seen that in the first year, in the treatments of S1S2, S3 and K, it caused an increase of 20, 27, 47 and 31% respectively, and in the second year it caused an increase of 11, 14, 15 and 1% performance compared to the control (S0) treatment. The highest amount of fresh weight was observed in the treatment of S3. The highest amount of dry weight in the treatment of S2 was 399 grams in the second year, which was significantly different from other treatments, which had a significant difference with other treatments so that in the K treatment compared to the S0, S1, S2, and S3 increased the acidity by 6, 3, 5 and 3%, respectively.The effect of chitosan treatment increased the amount of TSS compared to the control treatment. So that the effect of S1, S2, S3 and K treatments caused an increase of 7, 4, 3 and 10% in the amount of TSS, respectively, compared to the S0 treatment. The percentage of nitrogen on average in the first and second year in the S2, S3 and K treatments was higher than the S0 treatment and this increase was 5, 6 and 1%, respectively. However, in the S1 treatment, this value was less than the S0 treatment (13%). The highest percentage of potassium in the treatment of S2 in the first year was 4.62%. On average, in the treatments of S1 and S2, chitosan foliar spraying increased the amount of potassium by 1 and 15% compared to the S0 treatment. In the treatments of S3 and K, it caused a decrease in the amount of potassium compared to the S0 treatment. The highest percentage of phosphorus in the S1 treatment in the first year was 0.65%, in the first and second year in the S3 treatments and K increased the amount of phosphorus by 9% and 2%, respectively, compared to the S0 treatment. Although, in the S1 treatment. no difference was observed, in the S2 treatment, the amount of phosphorus decreased by 9% compared to the S0 treatment, the highest percentage of calcium was obtained in the S1 treatment in the first year, and the lowest amount of calcium was observed in the second year in the K treatment. Chitosan foliar spraying in the S1 treatment caused an 82% increase in the amount of calcium compared to the S0 treatment. The average comparison results showed that the highest amount of sodium in the S3 treatment in the second year was 0.275 ppm. On average, in the S3 and S2 treatments, chitosan foliar spraying caused an increase of 5 and 11% in the amount of sodium compared to the S0 treatment, but in the treatments of S1 and S2, it caused a decrease of 2 and 15% in the amount of sodium compared to the S0 treatment. The highest amount of ascorbic acid in the S3 treatment was 0.45 PPM, which was significantly different from other treatments. The lowest amount of ascorbic acid was 0.306 PPM in the S2 treatment. except for the S2 treatment, which caused a 9% decrease in the amount of vitamin C, in the S1, S3 treatments, and K increased by 14, 33, and 29%, respectively, compared to the S0 treatment.Conclusion The results of this experiment investigated the effect of chitosan on the growth and yield and some quality characteristics of tomato fruit. Based on the obtained results, the use of chitosan as a biological stimulant improves yield, fresh weight, dry weight, and dissolved solids. And it became ascorbic acid. However, in the case of nitrogen, phosphorus, potassium, sodium and calcium elements, there was no linear trend in the increase of elements. However, in general, chitosan foliar application increased the percentage of the investigated elements compared to the S0 treatment. So that the greatest effect in increasing yield, plant fresh weight, nitrogen, phosphorus and ascorbic acid was observed in the S3 treatment, also the highest amount of PH, TSS and sodium was observed in the K treatment, the highest amount of dry weight and potassium In the S2 treatment and the highest amount of calcium was observed in the S1 treatment.
Volume 46 - Issue 3
Soil Genesis and Classification
Mastaneh Rahimi Mashkaleh; Mohammad Amir Delavar; Mohammad Jamshidi
Abstract
Introduction: Imbalanced data remains a widespread and significant challenge, particularly impacting machine learning algorithms. Therefore, addressing imbalanced data classification has emerged as a crucial research area within the field of data mining. This issue, often characterized by a limited number ...
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Introduction: Imbalanced data remains a widespread and significant challenge, particularly impacting machine learning algorithms. Therefore, addressing imbalanced data classification has emerged as a crucial research area within the field of data mining. This issue, often characterized by a limited number of instances in one class and a substantial number in other classes, poses substantial hurdles for machine learning algorithms. Consequently, data mining experts and machine learning professionals are actively working on refining methods and models for classifying imbalanced data with the aim of improving the accuracy of such classifications. The principal objective of this study is to precisely detect and categorize samples from the minority class, ultimately enhancing the precision of soil class classification. This research is conducted in a specific region, encompassing the southwestern territories of Zanjan province.Materials and Methods: To achieve this objective, a total of 148 soil profiles were excavated using a regular grid pattern with an average spacing of 500 meters (and in some locations, up to 700 meters based on expert recommendations). After the samples were air-dried, they were transported to the laboratory. Physical and chemical analyses were conducted on all collected samples, including assessments of soil texture, soil pH, calcium carbonate equivalent, cation exchange capacity, electrical conductivity, organic carbon content, and gypsum content. Subsequently, the soil samples were meticulously classified and described up to the family level, following the comprehensive standards of the soil classification system. The most appropriate covariates were selected among 57 covariates including geomorphological and geological maps, digital elevation model (DEM), and data from Landsat 8 satellite images, using principal component analysis (PCA) and expert knowledge approaches for predicting soil classes selected. Saga-GIS and ENVI software were used to extract environmental covariates. Modeling of the soil-landscape relationship was performed using three algorithms, namely multinomial logistic regression (MNLR), random forest (RF), boosted regression tree (BRT) and ensemble model (after data balancing) in “R studio” software. To check the accuracy of the used model, the data was randomly divided into training and validation data. 80% of the data (118 profiles) were used for model training and 20% (30 profiles) were used as validation data for evaluation.Results and Discussion: The results of the selection of covariates showed that 10 information covariates of geomorphological maps, geological information and features extracted from the digital elevation model (DEM), including Analytical hill shading (AHS), sunrise, valley depth (VD), LS Factor, Channel network distance (CND), Topographic wetness index (TWI) and Multi-resolution ridge top flatness (MRRTF) were selected as input variables. Based on the results of profile analysis, the soils of the region at the subgroup level were categorized into five classes, with imbalanced distribution, including Typic Calcixerepts, Typic Haploxerepts, Gypsic Haploxerepts, Typic Xerorthents, and Lithic Xerorthents. The results of evaluation metrics such as overall accuracy and Kappa index were 65% and 0.32 for the RF algorithm, %60 and 0.35 for the boosted regression tree algorithm, 65% and 0.41 for the MNLR algorithm and after balancing the data with the ensemble model approach, it was 70% and 0.62 respectively. The results of two statistics of user’s accuracy and producer’s accuracy showed that among individual models, the multinomial logistic regression model has higher accuracy in predicting soil classes. Although the ensemble model has succeeded in predicting the soil minority classes well, due to the fact that the two weaker models of the RF and BRT are involved in the modeling, It showed lower values compared to the individual multinomial logistic regression model, in predicting some classes of the majority of soil, especially the two classes of Typic Haploxerepts and Typic Xerorthents.Conclusions: Conclusions: In summary, the results have demonstrated that when learning algorithms are individually applied, they do not exhibit high accuracy in spatially predicting soil classes. However, when these algorithms are amalgamated into an ensemble model, they exhibit remarkable accuracy in spatial soil class prediction, outperforming individual models in terms of performance and accuracy. Moreover, the ensemble model substantially enhances prediction accuracy and reduces the occurrence of misclassifications, especially at the subgroup level. While each specific model excels in predicting a particular soil classification, the cumulative ensemble models consistently outperform individual models in terms of overall performance and accuracy, underscoring the effectiveness of ensemble modeling in improving spatial soil classification.
Volume 45 - Issue 3
ALi Barikloo; Moslem Servati Khajeh; parisa alamdari
Abstract
Introduction: A variety of precise farming practices in arid and semi-arid regions such as Iran require periodic information on soil salinity and sodium content. Sodic soils have unfavorable physical and chemical properties due to the high percentage of exchangeable sodium (ESP). This problem reduces ...
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Introduction: A variety of precise farming practices in arid and semi-arid regions such as Iran require periodic information on soil salinity and sodium content. Sodic soils have unfavorable physical and chemical properties due to the high percentage of exchangeable sodium (ESP). This problem reduces the capacity of available water and growth of plants. To measure the percentage of exchangeable sodium, it is necessary to measure the amount of cation exchange capacity (CEC). Because determining CEC are time consuming, it is appropriate and economical to develop a method that determines ESP indirectly from easy-measured properties. One of the methods to study the relationships and correlations between different soil properties and their quantitative expression is the use of some statistical models. These models, called transfer functions, include data mining, regression models, artificial neural networks, and the coherent neural-fuzzy integrated system (CANFIS).Materials and Methods: The aim of this study was to develop an intelligent model (CANFIS) for predicting soil ESP from soil easy-measured properties in approximately 1450 ha of salt affected soils, South East of Urmia Lake, Bonab region, East Azarbaijan Province. For this purpose, 209 soil samples were taken by grid survey method from surface (0-25 cm) and then carried out laboratory for measure necessary soil properties. Soil acidity and electrical conductivity of samples were measured in a ratio of 1: 5 soils to water, soil tissue by hydrometric method, sodium cation by flame photometer and calcium and magnesium by returned titration method.Results and Discussion: Pearson correlation method showed that the accuracy of estimating intelligent models depends on the correct choice of first layer input information. Therefore, using the correlation matrix, the relationship between soil parameters (independent variable) and the percentage of exchangeable sodium (dependent variable) was determined. Sodium absorption ratio (0.961), electrical conductivity (0.808), pH (0.638), clay content (0.524), sand (0.482) and silt (0.389) have the greatest effect on estimation Percentage of exchangeable sodium in soil. Also, the positive relationship between soil reaction and the percentage of exchangeable sodium on the one hand and the high correlation between the percentage of exchangeable sodium and electrical conductivity indicate the importance of the fine soil. In this study, the relationship of linear regression between the percentage of exchangeable sodium and the ratio of sodium uptake with an explanation coefficient of 0.91 was calculated, which is significant at the level of 5% probability. Two important targets were designed in this paper. First target is determining performance of Fuzzy Neural Networks (CANFIS) in predicting ESP by sand, clay, pH, SAR, EC as input variable. The second target is evaluation of performance of CANFIS model by selected variable of PCA model. Results showed that the performance of second model was acceptable Model 1 justifies 88% of the changes in the percentage of exchangeable sodium by entering all inputs. But CANFIS model with higher inputs selected by PCA model (principal component analysis) including sodium adsorption ratio, electrical conductivity, soil reaction has higher accuracy. So that the values of root mean square error and correlation coefficient in the test stage for the first model were 0.88 and 3.25 and the second model was 0.96 and 1.0, respectively. Conclusion: These results demonstrated the superiority of intelligent models in explanation of the relationship between ESP and other soil easily-measured properties. In order to model the soil retrieval properties such as cation exchange capacity and to achieve the most suitable model, it is necessary to pay attention to the number and most effective input variables. Because the main goal is to provide a model with a minimum number of inputs as well as inputs that are easy to measure and in a short time. The results of quantification of the importance of variables in the CANFIS model confirm the use of three characteristics of sodium adsorption ratio, electrical conductivity of soil saturated extract and soil acidity in modeling the percentage of exchangeable sodium. The results of this study can be generalized to soils of similar arid and semi-arid regions. Also, due to the ambiguity of soil-related phenomena or the approximate values of the measured values of different soil properties and the uncertainty in the data, the use of hybrid models such as CANFIS that use fuzzy sets, It can be useful in fitting soil transfer functions.Keywords: Easly-measured Properties, Hard-measured Properties, PCA All right reserved.
Volume 46 - Issue 3
Plant Nutrition, Soil Fertility and Fertilizers
Masuod Shahrokhi; Saeid Shafiei; Hosein Shekofteh; Shapour Kouhestani
Abstract
Introduction: The quality of irrigation water has an important effect on the growth and concentrations of nutrients. The application of boron-rich irrigation water is a global issue and the most important boron pollution source in the environment. Poor water quality unavoidably leads to decreased growth ...
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Introduction: The quality of irrigation water has an important effect on the growth and concentrations of nutrients. The application of boron-rich irrigation water is a global issue and the most important boron pollution source in the environment. Poor water quality unavoidably leads to decreased growth of plants. One of the problems of irrigation in tropical regions is the high concentration of boron element in water and its concentration in irrigation water increases every year. In dry areas where agriculture takes place, boron is often found in high concentrations along with saline soils and salty waters. Boron stress occurs widely and limits plant growth and crop productivity worldwide. Boron is in the form of boric acid in the soil solution and it is washed from the soil in heavy rains, but it is not washed enough when it rains, and by accumulating in the soil, it poisons the plant and prevents its growth. Therefore, in arid and semi-arid areas, irrigation with groundwater that has a high boron content reduces crop growth. Therefore, this experiment aimed to evaluate the effect of activated carbon on nutrient concentrations by tomatoes, cucumbers, and eggplants under the boron stress of irrigation water. Materials and methods: To evaluate the effects of activated carbon on the concentrations and translocation of boron in the plant a factorial experiment with a completely randomized design and three replications was performed in the greenhouse conditions. Treatments included three plants (tomato, cucumber, and eggplant), three levels of boron concentration in irrigation water (0.03, 2.5, and 5 mg l-1) from a boric acid source, and four levels of activated carbon (0, 1, 2, and 3% soil). To prepare seedlings, first, a sufficient number of healthy seeds were selected and for better germination, they were placed in wet napkins for one day and night. Then the seeds were planted in seedling trays with coco peat substrate. In this stage, watering was done once every two days until finally, after 30 days and when the seedlings reached the four-leaf stage and the true leaves appeared, the plants were ready to be transferred to the pots. For cultivation, each of the plastic pots was filled with 3 kg of sampled soil, which was mixed with a proportion of activated carbon according to the type of treatment. Then, in the middle of each pot, several seedlings of the same size were planted. Then the pots were placed in the greenhouse according to the plan. The experiment was conducted with 36 experimental treatments in three replications and a total of 108 experimental units. The soil used was prepared with geographical coordinates (longitude 57˚ 37ʹ and latitude 28˚ 42ʹ) and depth of 0-30 cm and was classified according to the American classification system Sand, mixed, hyperthermic typical Torriorthents. During the growing period, the plants were irrigated daily according to the farm capacity (FC). The day temperature of 25 – 30 °C, the night temperature of 15 – 20 °C, and the relative humidity was 50 – 70%.Results and discussion: The results indicate that the main effects of boron and activated carbon levels had a significant effect (p < 0.01) on the concentration of iron, zinc, manganese, and copper in the aerial parts of the plant. With the amount of boron increased in the treatments, the amount of copper and iron in the aerial parts increased while the amount of manganese and zinc decreased. Regarding the effect of activated carbon, the results showed that by increasing the amount of activated carbon in the treatments, the amount of copper, manganese, and zinc decreased. In contrast, the amount of iron has increased. The highest concentration of iron in the aerial parts (219.6 mg kg-1) belonged to the level of 3% of activated carbon. Also, with the increase in activated carbon in the treatments, concentrations and accumulation of boron in the aerial parts decreased. The highest concentration of boron in the aerial parts (31.77 mg kg-1) was obtained in the cucumber and the level of 0% activated carbon, and the lowest concentration (5.75 mg kg-1) was obtained in eggplant and the level of 3% activated carbon.Conclusions: It is concluded that the use of activated carbon under boron stress conditions can reduce the concentrations and toxicity of boron in plants.
Volume 45 - Issue 3
Shohreh Moradpour; MOjgan Entezari; Shamsollah Ayoubi; Salman Naimi
Abstract
Impacts of land use and geomorphology on some heavy metal concentrations in a part of Zayandehroud dam watershed IntroductionWith the rapid development of industry and urbanization, soil pollution with heavy metals as a result ecosystem destruction has attracted global attention. Pollutants are considered ...
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Impacts of land use and geomorphology on some heavy metal concentrations in a part of Zayandehroud dam watershed IntroductionWith the rapid development of industry and urbanization, soil pollution with heavy metals as a result ecosystem destruction has attracted global attention. Pollutants are considered environmental threats and among pollutants, heavy metals are known for their non-degradability and physiological effects on living organisms even at low concentrations. The close correlation of magnetic properties and heavy metals shows that magnetic measurement is an efficient and cheap tool to detect heavy metal contamination in soils affected by heavy industries and traffic pollution. Magnetic minerals in soil may be inherited from parent rocks (lithogenic origin), pedogenesis (pedogenic origin), or may result from human activities (secondary ferromagnetic materials). The concentration of metals can be influenced by geomorphology and various soil properties such as organic carbon, electrical conductivity. Land use directly or indirectly affects the geochemical behaviors of heavy metals through regulating soil properties. The main objectives of this study were to investigate the effect of land use change on magnetic receptivity and the concentration of some heavy metals including zinc, copper, iron, nickel, chromium, cobalt and manganese in the 20 cm soil surface layers, and to explore spatial distribution of magnetic receptivity and heavy metals under different types of land use and geomorphological units in the studied area.Materials and MethodsThe present research was conducted in Isfahan province in the center of Iran with an area of 227 Km2. This area has an average temperature of 9.8 oC and an average annual rainfall of 324 mm and an altitude of 2380 meters a.s.l. Based on Kopen's classification, the climate was classified as semi-arid with cold winters. Geologically, it belongs to the Sanandaj-Sirjan zone, the dominant rocks of the area include limestone, shale limestone, slate and Quaternary sediments. The most important land uses in the region included pasture, rainfed and irrigated agriculture, and in terms of geomorphology, the region comprised river plains and pediments. Soil sampling was done by stratified random method. A total of 100 samples were collected from the surface layer (0-20 cm depth) in the summer of 2021. Magnetic susceptibility was measured at high and low frequencies using Bartington MS2 dual frequency sensor. The concentration of heavy metals including iron, zinc, manganese, nickel, copper, chromium and cobalt were measured by atomic absorption spectroscopy. pH, organic carbon, calcium carbonate, electrical conductivity were measured in all samples. Spearman's correlation coefficient was used to check the correlation between different parameters. Analysis of variance was applied to evaluate the effects of geomorphology and land use on heavy metals and magnetic susceptibility. Spatial analysis was performed for heavy metals and magnetic susceptibility, and the maps were prepared in ArcGIS v.10.7 software.Results and DiscussionThe results showed that there was a negative and significant correlation between calcium carbonate, heavy metals and geomorphology. There was no significant correlation between organic carbon and heavy metals in land uses. But there was a negative correlation in the river plains and alluvium. There is a significant negative correlation between electrical conductivity, copper, manganese, and nickel. In the use of agricultural lands and river plains, there is a positive correlation between low-frequency magnetic susceptibility and high-frequency magnetic receptivity with electrical conductivity. Also, pH showed a significant negative correlation with magnetic susceptibility in pasture land and had no relationship in other land uses. There is a positive correlation between calcium carbonate and frequency-dependent magnetic susceptibility in agricultural land use and river plains. There is a significant positive correlation between heavy metals and magnetic susceptibility in pediments and some land uses, especially in rainfed lands. The results of analysis of variance showed significant difference (p*<0.05) in land use regarding heavy metal concentrations. In this analysis, there was a significant difference between cobalt, nickel and manganese elements according to land use, and the magnetic susceptibility among the studied geomorphic surfaces. According to the results of the test, there was a significant difference for heavy metals in various geomorphic surfaces. The content of iron, chromium, cobalt, nickel and manganese in river plains and pediment had significant differences with hills.ConclusionThe present study was conducted with the aim of clarifying the effect of land use and geomorphology on magnetic susceptibility and concentration of heavy metals in a part of the Zayandeh River watershed in Isfahan province. The average of nickel and manganese in the soils of the study area is higher than the normal range, due to parent materials effects and agricultural activities (plowing and irrigation) accelerate the soil formation processes and increase the amount of these elements in the soil. The highest concentration of cobalt, iron, zinc, copper, nickel and chromium elements were observed in dryland farming. In addition, investigating the spatial distribution of magnetic receptivity values and heavy metals in different places are significantly different. Higher values of magnetic susceptibility were seen in the center of the studied area. Spatial distribution of heavy metals iron and chromium are concentrated in the center of the region and other metals are concentrated in the west and northwest. Probably, parent materials such as shale, dolomite, limestone and sandstone and weathering and release of elements in the soil increase the concentration of these elements in the region.Keywords: Geomorphology, land use, LSD test, kriging
Volume 46 - Issue 3
Biofuels
Mojtaba Malekzadeh; Reza Yeganeh; Bahram Ghamari; shaban ghavami jolandan
Abstract
Introduction: Biogas is a natural and cost-effective source of energy that leaves significant impacts on the environment and industries, widely produced and utilized in many countries. This gas is generated through the anaerobic digestion of organic materials, including animal manure, food waste, and ...
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Introduction: Biogas is a natural and cost-effective source of energy that leaves significant impacts on the environment and industries, widely produced and utilized in many countries. This gas is generated through the anaerobic digestion of organic materials, including animal manure, food waste, and sewage. Microorganisms play a crucial role in the biogas production process by feeding on biomass. The digestion carried out by these microorganisms produces methane, constituting approximately 50-70% of biogas, which is flammable and used for cooking, cooling and heating, electricity generation, methanol and steam production, waste management, and mechanical power. Given these benefits, biogas production holds special significance, and extensive research has been conducted globally in this field, yielding valuable results. In the present study, we aim to investigate and evaluate the influence of lentil skin as a biomass on the quantity and constituents of produced biogas.Materials and Methods: This research was conducted in the Biosystems Mechanics Workshop of the Faculty of Agriculture, Ilam University. The objective of this study was to investigate the effect of lentil skin on biogas production and analyze its constituent components. The workflow typically comprised four stages. In the first stage, fresh lentil skins were broken down into smaller pieces and stored in a suitable environment to be used as digester feedstock for the experiment. Shredding organic waste aids in the digestion process. The second stage involved providing optimal conditions for microbes, which require warmth. Accordingly, the temperature was maintained at an average of 28-30 degrees Celsius during the experiment.The third stage involved the actual digestion process, where anaerobic digestion took place in large tanks, resulting in real biogas production. For this purpose, materials were combined in predetermined proportions (1:1) and loaded into the digesters. In each stage, 5 kilograms of lentil skin were combined with 5 kilograms of water and added to the digester. The experiment was conducted in three repetitions, employing fixed digesters, digesters with agitation every three days, and digesters with daily agitation as influencing factors. The quantity of biogas production and its components were examined over a 30-day period. Gas sampling occurred every 10 days, while pH and gas pressure were measured every 72 hours. In the final stage, the gas underwent purification by removing impurities and carbon dioxide. The amount of gases produced from lentil skin was measured using a chromatograph with a TCD detector. This instrument employs chromatography-based separation. It's worth noting that 9 gas capsules specifically designed for automobiles were used to construct the digesters. The construction stages of the digesters included cleaning, coloring, and installing connections. Moreover, to create uniform temperature and concentration conditions inside the tank, inlet and outlet connections were carefully designed and installed. A safety valve was also installed to ensure the safety of the digesters.Results and Discussion: The obtained results, including loading conditions, pH levels, and internal pressure within the digester during the experiment, and the quantity and components of biogas, were examined across all samples. Statistical methods, including Analysis of Variance (ANOVA) and Duncan's mean comparison test, were employed for data analysis. The results indicated that digester agitation directly influences the pH levels, with the highest pH observed in digesters with daily agitation, displaying the most significant fluctuations. Furthermore, digester agitation has a direct impact on the biogas production levels, enhancing structural effects within the digester. However, frequent agitation repetition has a negligible effect on the amount of biogas produced. The average methane production rates in this process were 34.06% mol for digesters with daily agitation, 23.09% mol for digesters with agitation every three days, and 17.32% mol for fixed digesters.Conclusion: Currently, a significant portion of the world's energy demand is met through fossil fuels, the combustion of which releases carbon dioxide and various pollutants, including sulfur and nitrogen oxides, which are highly harmful. Consequently, in recent years, there has been a growing inclination towards utilizing various renewable energy sources. One crucial energy source that also provides a solution for waste reduction is biogas. Given the increasing importance of sustainable energy development and the need for waste management, anaerobic digestion technology and biogas production have rapidly grown. Therefore, the findings of this research underscore the importance of exploring innovative methods and utilizing diverse biological resources in managing and optimizing the biogas production process.
Volume 46 - Issue 4
Agricultural mechanization
Majid Namdari; Shahin Rafiee; Soleiman Hosseinpour
Abstract
Introduction Considering the essential role of the agricultural sector in Iran's economy, it is very important to investigate and identify optimal production methods from an economic point of view. The purpose of this study is to calculate the economic indicators of sugar beet production, use of the ...
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Introduction Considering the essential role of the agricultural sector in Iran's economy, it is very important to investigate and identify optimal production methods from an economic point of view. The purpose of this study is to calculate the economic indicators of sugar beet production, use of the Data Envelopment Analysis (DEA) method to identify the efficient units, and use of the Adaptive Neuro-Fuzzy Inference System (ANFIS) method to predict the benefit-cost index based on the consumption of production inputs in Hamedan province.Materials and Methods In this study, 88 farmers were studied. Data were collected from Hamadan province, Iran. Inputs included labor, machinery, diesel fuel, electricity, seeds, chemicals, farmyard manure, chemical fertilizers, and irrigation water. The indices of gross revenue, net income, gross income, economical productivity and benefit-cost ratio were calculated using information obtained from farmers. Then technical, pure technical, scale and cross efficiencies were calculated using CCR and BCC models for farmers. The benefit-to-cost ratio was considered as the economic index criterion in modeling with ANFIS. In this modeling, value of various inputs used for sugar beet production were selected as input variables. Various membership functions such as Triangular, Trapezoidal, Gaussian, Logarithmic and Gbell functions were tested. Also, different configurations were examined to provide the best configuration that predicts the model. In order to measure the accuracy of ANFIS models for estimating the observed values some quality parameters including the coefficient of determination (R2), root mean square error (RMSE) the mean relative error (RME) between the observed and the predicted values were applied to evaluate the performance of different models with different configurations.Results and Discussion The results showed that most of the production costs were in the category of variable costs. Variable costs account for 84% and fixed costs account for 16% of the total costs of sugar beet production. Cost of labor, water consumption, and land rent have the largest share of costs among all fixed and variable costs. The indexes of gross income, net income and benefit-cost ratio were obtained as 1188.99 $ha-1, 694.28 $ha-1 and 1.34, respectively. The results of data envelopment analysis showed that from the total of 88 farmers, considered for the analysis, 19 and 55 farmers were found to be technically and pure technically efficient, respectively. In other words, the farmers who are identified with the BCC model are more efficient than the farmers who are identified with the CCR model. Average technical efficiency, net technical efficiency, and scale efficiency were calculated as 0.73, 0.94 and 0.77, respectively.Data envelopment analysis indicates that farmers should focus on increasing the degree of mechanization of production by reducing the cost of human labor. The saving percentage of total input costs in the CCR model is higher than the BCC model. Optimization of input consumption in sugar beet production decreased the cost by 51.64% in the CCR model and by 28.27% in the BBC model. To predict the economic performance using inputs in sugar beet production, the three-layer arrangement with seven parameters obtained the best results. The modeled ANFIS is able to predict economic performance values with R2 of 0.96. This prediction is acceptable due to its high coefficient of determination and can be used in modeling.Conclusion Considering the high share of variable costs compared to fixed costs, it can be concluded that by applying appropriate management methods, the total costs of sugar beet production in Hamadan province can be significantly reduced. By mechanizing farms, the variable costs of farms can be reduced significantly. If the cultivated land does not have a problem with weeds, the use of conventional seeds can also reduce production costs. The DEA results showed that based on the CCR model, about 78.4% of farmers produce outside the efficiency and by providing management solutions taken from efficient DMUs (the recommendations of this study), they can reduce consumption costs by keeping product yield constant. The results of multi-level ANFIS implementation showed that the three-level ANFIS structure including four ANFIS models in the first level, two ANFIS models in the second level and a final model in the third level have the best performance for benefit-cost ratio prediction. It is proposed that implementation of multi-level ANFIS is a useful tool in helping to predict the economic indices of agricultural production systems.
Volume 46 - Issue 4
Soil, Water and Plant Relationships
hoda karimi; Shahriar Mahdavi; nasrin hasanzadeh; rouholah karimi
Abstract
Introduction Soil and water pollution, especially pollution by heavy metals such as cadmium,, has been noticed in many modern urban and industrial societies. If heavy metals accumulate in the soil, the capacity of the soil to keep the metals decreases, as a result, they enter the product and their bioavailability ...
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Introduction Soil and water pollution, especially pollution by heavy metals such as cadmium,, has been noticed in many modern urban and industrial societies. If heavy metals accumulate in the soil, the capacity of the soil to keep the metals decreases, as a result, they enter the product and their bioavailability increases. Today, the use of biochar is suggested as a healthy method to control heavy metal pollution in the soil.In this research, in order to investigate the concentration of cadmium metals in soil and leaves in the exposure of cadmium stress and using biochar to investigate some physiological indicators of leaves and also to investigate the level of soil composition in 2 varieties of grapes in Malayer city, grape cuttings in plastic pots It was cultivated in the research greenhouse of Malayer University and Faculty of Agriculture.Materials and Methods In this experiment, the effect of biochar on two grape varieties (white Soltana and perlet) was investigated in the face of 100 mg/kg cadmium stress. After applying cadmium stress and using biochar (3% by weight) in the tested pots, The soils of the rhizosphere area were collected after 2 months of applying stress, and the cadmium concentration was done in the form of 5-stage classification in the research laboratory of Malayer University and finally analyzed by atomic absorption device. Leaf samples were also collected after about 2 months of applying stress and biochar, and physiological indicators such as ion leakage, chlorophyll, phosphorus and relative water content were measured.The data related to each treatment (three replications) were carefully recorded and analyzed using SPSS software. EXCEL software was used to draw graphs. Duncan's test was used at a significance level of 1%.Results and Discussion The results showed that cadmium stress decreased the amount of chlorophyll and the relative content of water and also increased the amount of ion leakage. It was also observed that the application of biochar in both grape varieties increased the relative content of water, chlorophyll and phosphorus and reduced the amount of ion leakage to some extent. In the chemical forms of the soil, the use of biochar caused the reduction of exchange and carbonate forms and the increase of organic, oxide and residual forms. Biochar changed the easily replaceable parts of cadmium to those that are less available. In the conditions of cadmium stress, the use of biochar in soil can play a very important role in plant indicators such as relative water content, ion leakage, chlorophyll and phosphorus.The application of biochar decreased the fraction of exchangeable and carbonated cadmium, while the forms bound to Fe-Mn oxide, organic form and residual fractions increased.It was observed that the availability of heavy metals in the soil was significantly reduced with the addition of biochar compared to the control. Biochar significantly reduced ion leakage in both grape cultivars compared to untreated soil. In the organic form, the white Soltana variety in the presence of biochar and stress of 100 mg/kg of cadmium in the soil (6.57) compared to the samples without the presence of biochar (3.39) had an increase of 48.40% in the average concentration of cadmium. In Perlet cultivar, the percentage of increase was 21.45%, all of which showed an increase in organic form in the presence of biochar.Cadmium in soil in exchangeable and carbonate forms decreased after biochar application.In the residual form, the White Soltana variety in the presence of biochar and stress of 100 mg/kg of cadmium in the soil (20.88) compared to samples without the presence of biochar (15.47) had an increase of 34.97% in the average concentration of cadmium. In Perlet cultivar, the percentage of increase was 30.34%, which all showed the increase of residual form in the presence of biochar. Our results showed that the application of biochar can reduce the availability and toxicity of cadmium. Conclusion According to the results of this research, the application of biochar in the soil can be considered as an efficient management solution to control cadmium in areas contaminated with this heavy metal and can cause positive changes in plant leaf indices.Changes in the concentration of cadmium in different soil forms of grape cultivars as a result of the use of grape trunk biochar show that the use of biochar is a good strategy to reduce the risks of transferring cadmium to humans and the environment in metal-contaminated soils.
Volume 46 - Issue 4
Post-harvest technology
Hassan Masoudi; Seyed Mahmood Asadi; Gholamreza Akbarizadeh
Abstract
Introduction: In sugar factories, control of sugar crystals growth in the granulation stages is very important to produce sugar grains with a special and required size. Machine vision systems can determine the size of sugar crystals. The main challenge of image processing systems is the lack of capable ...
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Introduction: In sugar factories, control of sugar crystals growth in the granulation stages is very important to produce sugar grains with a special and required size. Machine vision systems can determine the size of sugar crystals. The main challenge of image processing systems is the lack of capable algorithms to separate contact and overlap crystals accurately. So far, various algorithms have been developed to detect crystals and remove their overlapping. However, these methods have not been able to fully detect and separate the overlap of crystals. The purpose of this study was to provide an appropriate image processing algorithm for determining the size of crystals in sugar baking solution (massecuite), which gives us the characteristics of size and shape for the particles in the baking pot instantly to evaluate and improve the quality of the final product.Materials and Methods: The massecuite samples were provided from Debal Khozaei Sugarcane Agro-industrial Company, Ahvaz, Iran. After preparation of the sugar crystals samples under lam and lamer (microscope slides), a digital camera with two Megapixel resolution, attached to a ZS9 Olympus microscope, was used for image capturing. Then, using MATLAB image processing toolbox, the color image (RGB) transferred to grey scale. A mixture of structural operations such as erosion and expansion with spatial filters including median filter were used to remove the image noises. The function of histogram local adjustment was used to improve image contrast. Three methods of segmentation including convexity, fuzzy clustering, and multiplicative intrinsic component optimization (MICO), along with their combination were used to segment the image of massecuite crystals. A reference image was used to determine accuracy of the image processing algorithms. To do this, the massecuite crystals image was manually segmented by Image J software. All segmentation algorithms were applied on the reference image, and seven geometrical parameters, including the mean aperture (MA), coefficient of variation (CV), and standard deviation (SD) were calculated for all the sugar particles in the image. Finally, the percent of MA measurement error was calculated for each sugar crystal to find the best algorithm.Results and Discussion: In manual segmentation, the number of sugar crystals in the selected image was 26. In the manually segmented image, the average of MA, SD and CV for sugar grains in the image were 0.422 mm, 0.157 mm and 37.18% respectively. The relatively large CV of the calculated geometrical parameters indicated the non-uniformity of the sugar particles size inside the massecuite. The convexity method was able to perform well in some areas of the image, and in some other areas, it could not detect the contact between the crystals. The value of the SD and CV of all the geometric parameters determined by the convexity method were greater than the reference values determined by the manual segmentation. This indicates the weaker performance of this method in determining the sugar crystals size compared to the manual method. The values of SD and CV of all geometric parameters determined by the combined fuzzy-convexity method were greater than the reference values, but lower than the values of the convexity method alone. So, the combination of the fuzzy clustering method with the convexity method improved the segmentation performance of crystal images. The SD and CV values of all geometric parameters determined by the combined MICO-convexity method were greater than the reference values, but lower than the values of convexity and fuzzy-convexity methods. This point shows the better performance of the combined MICO-convexity method in segmenting the images of sugar crystals compared to the other two methods. The average of MA, SD and CV for sugar crystals in the image were 0.382 mm, 0.150 mm and 39.23% respectively and had no significant difference with the reference method values in 5% probability level. The mean error of MA determined by the combined MICO-convexity algorithm was 13.24% and Pearson correlation factor was 0.88. As a result, the combined MICO-convexity method was proposed to determine the size of sugar crystals in massecuite.Conclusion: After applying different algorithms on the selected image of sugar crystals in massecuite, it was found that the combined MICO-convexity method can separate sugar crystals well. Also, the CV obtained for this image segmentation algorithm was not much different from the CV of the manual reference method, so this algorithm can be used in the image processing system of the massecuite crystals.
Volume 46 - Issue 4
Post-harvest technology
Esmaeil Mirzaee- Ghaleh; Fardin Aayri Samlhe; Amir Hossein Afkari Sayyah
Abstract
Introduction As the most important source of calories and protein, bread has a special role and importance in the nutrition of the country, and its cheapness has caused it to replace other food items in the diet in recent years. The increase in bread consumption in the low-income and vulnerable groups ...
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Introduction As the most important source of calories and protein, bread has a special role and importance in the nutrition of the country, and its cheapness has caused it to replace other food items in the diet in recent years. The increase in bread consumption in the low-income and vulnerable groups has been more intense due to the low volume of supply of other food products and the excessive and continuous increase in the price of other alternative products. Flat bread has the highest consumption statistics among other breads in Iran. One of their types is Barbari bread, which is the second most consumed bread after lavash bread in Iran. Therefore, the health and quality of consumed Barbari bread is of particular importance. For this purpose, this study was conducted with the aim of the effect of storage time of Barbari bread based on the characteristic of smell using the olfactory machine system based on eight metal oxide semiconductor sensors.Materials and Methods An odor machine system based on eight MOS sensors was carried out in order to investigate the effect of bread storage time based on odor characteristics. Designed system includes data acquisition system, sensors, shield of sensors, sample container, power supply, connections, electric valves, air pump and air filter. The sensor array was consisted of the 8 MOS sensors that each one reacts to specific volatile compounds. These sensors are widely used in olfactory machines because of their high chemical stability, high durability, low response to moisture and affordable prices. These are the most commonly used sensors in electronic nose system. Sensors are the main components of an electronic nose system therefor it is necessary to select the able sensors to detect differences among samples. In order to carry out the test, the sample was placed in sample container and in the baseline correction step (150 seconds), clean air was passed through the sensors to transmit the response of sensor array to steady state. At the injection step (180 seconds), the sample headspace was transmitted and passed through sensors chamber. Output voltage of each sensor depends on the type of sensor and its sensitivity. At the cleaning step (150 seconds) the clean air was passed through sensors to get the sensor array responsive to a stable state. Also, at this step the pump removed the odor remaining inside the sample container and system is prepared for the next test. The signals obtained from the sensors were recorded and then pre-processed.Results and Discussion The olfactory machine system based on eight metal oxide semiconductor (MOS) sensors was investigated with the PCA pattern recognition method due to the storage time of Barbari bread at four different temperatures. The data obtained from the signals processing with fractional method were used as input of PCA. The results of principal component analysis with two components PC1 and PC2 are 95, 90, 86 and 85%, respectively, for Barbari bread that is stored at room temperature (in the table), refrigerator temperature (4°C), room temperature (in foil) And the temperature of the freezer was placed, it showed. The results obtained from the QDA analysis to determine the quality of Barbari bread at 4 °C for 9 days, at room temperature (in foil) and (on the table) for 5 days and Barbari bread at the freezer temperature of the refrigerator (-18 °C) for 15 days of storage with classification accuracy of 98.52, 96, 100 and 97.35% respectively. The results of LDA analysis for the signals obtained from the olfactory machine, in the classification of the duration of storage of Barbari bread at refrigerator temperature, room temperature (in the table), room temperature (in foil) and refrigerator freezer temperature, respectively, with classification accuracy of 79.26 and 85.33, 78.67 and 75.22 percent were obtained. Also, according to the output obtained from the loading linear graphs and the radar graph, the smell of Barbari bread has the most and the least effect on the MQ9 sensor and the TGS813 sensor, respectivelyConclusion. An olfactory machine system based on eight metal oxide semiconductor (MOS) sensors was investigated for the Barbari bread time retention effect at four different temperatures. The results of principal component analysis with two components PC1 and PC2, for Barbari bread at room temperature (the table), refrigerator temperature, room temperature (in foil) and It showed that they were exposed to freezing temperatures. The results obtained from QDA analysis to detect the quality of Barbari bread at 4°C in room temperature (in foil) and (in the table) and refrigerator freezer temperature respectively. The results of LDA analysis for the classification of Barbari bread at refrigerator temperature, room temperature (in the table), room temperature (in foil) and freezer temperature of the refrigerator. The was obtained. Also, according to the output obtained from the loading linear graphs and the radar graph, the smell of Barbari bread has the most and the least effect on the MQ9 sensor and the TGS813 sensor, respectively.
Volume 46 - Issue 4
Energy and Renewable Energies
Abolfazl Hedayatipour; Mohsen Soleymani; Mostafa Kiani Deh Kiani
Abstract
Introduction In recent years, due to its availability and low environmental pollution, the use of Earth-Air Heat Exchanger (EAHE) has been developed as an efficient energy system in heating and cooling residential buildings and agricultural greenhouses. In this system, air is circulated by a fan through ...
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Introduction In recent years, due to its availability and low environmental pollution, the use of Earth-Air Heat Exchanger (EAHE) has been developed as an efficient energy system in heating and cooling residential buildings and agricultural greenhouses. In this system, air is circulated by a fan through a pipe buried deep in the ground. Depending on the geographical location and soil type, the soil temperature at a depth of 2-3 meters remains unchanged throughout the season. Of course, this depth varies throughout the year and according to climatic changes. The heat exchange between the soil and the air inside the pipe depends on the type of soil and its moisture content, the length and diameter of the air transmission pipe, the depth of burial and the velocity of the air flow (air velocity). Air circulation can be done in an open-loop or closed-loop circuit.Materials and Methods: A factorial experiment was conducted in the form of a completely randomized block design with two factors (pipe length at three levels (34, 17 and 52 meters) and air velocity at two levels (5 and 10 m/s)) in three replications, to investigate the effect of these factors on the coefficient of performance (COP), system efficiency and outlet air temperature. The experiment was conducted in a greenhouse in Arak city, Iran, in Joune 2022. This 150 square meter greenhouse was equipped with geothermal equipment. Air was circulated through a 200 mm diameter PVC pipe buried three meters deep in the ground. Air was circulating through an open loop circuit. Dependent variables were measured during the hot hours of the day (from 12:00 to 18:00) for one week at the end of July. The air temperature at the fan inlet and at 17, 34 and 52 meters along the pipe was measured by a single-channel data logger. Hourly changes in outlet air temperature, COP and efficiency were measured in a 24-hour period and plotted using Excel software.Results and DiscussionThe outlet air temperature for the pipe length of 34 and 52 m did not change when the air velocity decreased from 10 m/s to 5 m/s. But for the pipe length of 17 m, the maximum temperature, COP and efficiency were observed at an air velocity of 5 m/s. Regardless the air velocity, the average temperature of the outlet air for the three levels of the pipe length was 28.5, 25.5 and 25.3°C, respectively. The outlet air temperature was almost the same for the 34 and 52 m pipe lengths. In other words, the optimal length of the pipe is about 34 meters. The mean efficiencies for these two pipe length levels were 0.69 and 0.66, but the COP depended on the air velocity. The average COP for air velocity of 5 and 10 m/s was obtained 1.4 and 2.5, respectively. Based on these results, the best performance of the system in terms of output temperature reduction, cooling efficiency and COP is obtained in situation that the length of the pipe is 34 m and the air velocity is 10 m/s. when the length of the pipe is 17 meters, the temperature of the air outlet at two velocities of 10 and 5 m/s was 29.9 and 27 °C, respectively. The cooling efficiency and COP at two velocity of 10 and 5 m/s, were 0.34, 0.54; and 2.1, 1.7 respectively. If the desired temperature is 28-30 °C, pipe length of 17 m and the air velocity of 5 m/s is recommended. The results of hourly performance analysis showed that the highest difference between inlet and outlet air temperatures, is obtained at middle hours of the day. The higher the ambient temperature, the higher the efficiency of the EAHE system. ConclusionThis system successfully met the cooling needs of a model greenhouse in the weather conditions of Markazi Province in June. Based on the results, the optimal pipe length and air velocity were obtained as 34 m and 10 m/s, respectively. The average air outlet temperature and cooling efficiency were 25.5, 0.66 and 2.5 respectively. The higher the ambient temperature, the higher the EAHE efficiency. This is mainly due to the higher temperature difference between the outgoing and incoming air during the hottest hours of the day. As a result, system efficiency and COP increase at the hottest hours of the day.
Volume 30 - Issue 1
M. Olamaee; M. Elhamifard
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 30 - Issue 1
E.A. Askari; T. Tavakoli hashjin; S. Minaei; S. Sabori; M.R. Alizadeh
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 30 - Issue 3
Mohammad Javad Sheikhdavoodi; S. Minei
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 30 - Issue 3
N. Rangzan; A. Landi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 30 - Issue 3
A.A. Adelpour; M. Soufi; A.K. Behnia
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 30 - Issue 4
M.R. Havasi; M.J. Shaykh Davoodi; N. Alaei Shini; A. Mostaan
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 30 - Issue 2
A. Bigdeli; M. Zarra Nezhad; M.A. Asoodar; H. Basirzadeh; M. Baradaran
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 30 - Issue 2
M.E. Ghobadi; A. Bakhshandeh; H. Nadian; G Fathi; M.H. Gharineh; K. Alami-saied; M. Ghobadi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 4 - Issue 1
A. Riazi Hamedani
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 29 - Issue 4
M. Mohammadi; A. Moezzi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 29 - Issue 4
H.R. Moradi; M. Behzadfar; H.R. Sadeghi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 29 - Issue 4
M. Ghasemi Nejad; M.J. Shaykh Davoodi; M. Almasi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 29 - Issue 2
R. Ghasemi- Fasaei; A. Ronghi; M. Maftoun; N. Karimian
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 29 - Issue 2
F. Norbakhsh; H. Shariatmadari; A.M. Rezaei
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 29 - Issue 3
H. Khdemi; J. Mohammadi; M. Nael
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 29 - Issue 3
S.M.H. Mortazavi; K. Arzani; M. Barzegar
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 28 - Issue 2
Y. Mansoori; S. Minaei
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 28 - Issue 2
M. Chorom; F. Abdollahi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 28 - Issue 1
B. Jamshidi; S. Minaee; M.H. Khoshtaghza
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 28 - Issue 1
M.J. Sheikhdavoodi; S. Minaee; M. Almasi; B. Ghobadian
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 28 - Issue 1
A Zaeti; Y. Rezainejad; M. Afyuni; H. Shariatmadari
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 28 - Issue 1
S. Jafari; M. Baghernejad; M. Chorom
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 27 - Issue 2
M.H. Salehi; H. Khademi; J. Givi; M. Karimiyan
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 27 - Issue 2
M. Chorom; F. Sadegh zade
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 27 - Issue 1
M. Meskarbashee; A. Kashani
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 25 - Issue 2
M.A. Beh-Ayin; M.J. Sheikhdavoodi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 25 - Issue 2
E. Chavoshi; H. Khademi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 25 - Issue 2
N. Arian-nia; H. Nadian; A. Siada; G. Nour- Mohamadi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 21 - Issue 1
H. Bahrami; M. Almassi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 21 - Issue 1
A.R. Barzegar
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 15 - Issue 1
A. Pashai
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 15 - Issue 1
M. Almassi; H. Bahrami
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 14 - Issue 1
B. Najafi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 14 - Issue 1
M. Almassi; H. Bahrami; M.J. Shikhdavodi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 14 - Issue 1
A. Pashai
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 11 - Issue 1
H. Ghadiri
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 8 - Issue 1
K. Jazayeri
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 7 - Issue 1
B. Naghshineh-pour
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 5 - Issue 1
M. Almassi
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 1 - Issue 1
A. Alizadeh
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 13 - Issue 1
F. Kaveh
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 18 - Issue 1
H.A. Kashkuli; M. Mashal
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 24 - Issue 2
M.H. Khoshtaghaza; M. Hydari; T. Tavakoli
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 3 - Issue 1
A. Alizadeh
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
Volume 3 - Issue 1
A. Mazaheri
Volume 1.32, مجموعه مقالات منتشر شده در حوزه مهندسی زراعی قبل از تفکیک مجله علمی کشاورزی در سالهای 1354 تا 1388 , February 1976
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