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.
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.
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.
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.
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 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.
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.
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.
S. Baghbani; M. Baranimotlgh; E. Dordipour
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.
Soil Chemistry and Pollution
M Ayeneh Heydari; M Hejazi Mehrizi; A Jafari; M Yousefifard
A. Kiani Harchegani; S.A. Eftekhari
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.
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.
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.
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.
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.
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.
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.
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.
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.
M. Razzaghi; N Khademol Hosseini; M almasi; L Joukar; S.H. Ahmadi; A. Astakhr
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.
