Research Paper
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.
Research Paper
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.
Research Paper
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.
Research Paper
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
Research Paper
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
Research Paper
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.
Research Paper
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.
Research Paper
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.
