University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Removal of Lead and Copper from Aqueous Solution Using Gamma Rays and Titanium Dioxide NanoparticlesRemoval of Lead and Copper from Aqueous Solution Using Gamma Rays and Titanium Dioxide Nanoparticles297529858042710.22059/ijswr.2020.286653.668283FAArezoAtashbarM.Sc. Student, Department of Soil Science, College of Agriculture, University of Zanjan, , Zanjan IranMohammadBabaakbariAssistant professor, Department of Soil Science, College of Agriculture, University of Zanjan, Zanjan, Iran.EbrahimMoghisehAssistant professor, Nuclear Agriculture Research School. Nuclear Science and Technology Research Institute,Karaj, IranSetareAmanifarAssistant professor, Department of Soil Science, College of Agriculture, University of Zanjan, Zanjan, IranJournal Article20190811Nowadays ionizing beams such as gamma rays are used to remove organic and inorganic contaminants from wastewater and sewage sludge. The objective of this study was to investigate the effects of gamma rays and titanium dioxide nanoparticles on the concentration of lead and zinc in aqueous solution at different pH. For this purpose, the effect of gamma rays at 4 levels (0, 4, 8 and 16 kGy) and chemical modifier of titanium dioxide at three levels (0, 2 and 4 g.l<sup>-1</sup>) with 0 and 10% methanol in water solutions with different pH (2, 4 and 6) on the removal of Pb and Cu were investigated. The experiment was performed as a factorial in a completely randomized design. The results showed that the lead and copper concentrations decreased with increasing pH. The concentrations of copper at pH level of six, 16 kGy of gamma radiation and the level of 4 g.l<sup>-1</sup> of titanium dioxide (without methanol) decreased more. The concentration of lead at the level of pH six and 16 kGy of gamma radiation and levels of 2 and 4 g.l<sup>-1</sup> of titanium dioxide (without methanol and with methanol) had a further decrease. Titanium dioxide showed the highest effect and gamma ray had the lowest effect on the removal of copper and lead from aqueous solution.Nowadays ionizing beams such as gamma rays are used to remove organic and inorganic contaminants from wastewater and sewage sludge. The objective of this study was to investigate the effects of gamma rays and titanium dioxide nanoparticles on the concentration of lead and zinc in aqueous solution at different pH. For this purpose, the effect of gamma rays at 4 levels (0, 4, 8 and 16 kGy) and chemical modifier of titanium dioxide at three levels (0, 2 and 4 g.l<sup>-1</sup>) with 0 and 10% methanol in water solutions with different pH (2, 4 and 6) on the removal of Pb and Cu were investigated. The experiment was performed as a factorial in a completely randomized design. The results showed that the lead and copper concentrations decreased with increasing pH. The concentrations of copper at pH level of six, 16 kGy of gamma radiation and the level of 4 g.l<sup>-1</sup> of titanium dioxide (without methanol) decreased more. The concentration of lead at the level of pH six and 16 kGy of gamma radiation and levels of 2 and 4 g.l<sup>-1</sup> of titanium dioxide (without methanol and with methanol) had a further decrease. Titanium dioxide showed the highest effect and gamma ray had the lowest effect on the removal of copper and lead from aqueous solution.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Modeling of Velocity and Hydraulic Gradient in Non-Darcian Flows Using the Concept of Conformable Fractional DerivativesModeling of Velocity and Hydraulic Gradient in Non-Darcian Flows Using the Concept of Conformable Fractional Derivatives298729988042810.22059/ijswr.2020.299566.668544FANooshinEslahiDepartment of Irrigation and Reclamation Engineering, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, P. O. Box 4111, Karaj, 31587-77871, Iran.AlirezaVatankhahAssociate Professor, Department of Irrigation and Reclamation Engineering, University College of Agriculture and Natural Resources, University of Tehran, P. O. Box 4111, Karaj, 31587-77871, Iran0000-0002-0421-3164MohammadSedghi AslAssociate Professor, Soil Science Department, College of Agriculture, Yasouj University, P.O.BOX: 353, Yasouj, 75918-74831, Iran.Journal Article20200318The increase of flow velocity and Reynolds number in coarse porous media and the subsequent violation of Darcy's law, force to analyze the flow based on nonlinear relations of hydraulic slope and flow velocity. So, it is necessary to study nonlinear relationships more accurately. The purpose of this study was to investigate the performance of fractional-order model and the effect of conformable derivatives on improving the relationship between flow velocity and hydraulic gradient. Therefore, by determining the acceptable range for the fractional-order model, a nonlinear model based on conformable derivatives of the Izbash equation for the fully developed turbulent flow was presented and solved analytically and the parameters of the proposed model were determined using laboratory data analysis. The optimal values of the model parameters including coefficient <em>a</em> and the order of fractional derivative α, which can be varied in the range of (0-2), were calculated for each laboratory data set. The results were compared with the experimental data and the analytical solution of Izbash equation and a good agreement was found to the non-Darcian flow laboratory data. Moreover, using dimensional analysis method, Reynolds number was introduced as an effective factor on α coefficient and a suitable relationship was observed between the order of fractional derivative α and Reynolds number indicating the hydraulic concept of fractional-order model. According to the present study, the fractional order α is not only a fitting coefficient, but it represents a physical concept.The increase of flow velocity and Reynolds number in coarse porous media and the subsequent violation of Darcy's law, force to analyze the flow based on nonlinear relations of hydraulic slope and flow velocity. So, it is necessary to study nonlinear relationships more accurately. The purpose of this study was to investigate the performance of fractional-order model and the effect of conformable derivatives on improving the relationship between flow velocity and hydraulic gradient. Therefore, by determining the acceptable range for the fractional-order model, a nonlinear model based on conformable derivatives of the Izbash equation for the fully developed turbulent flow was presented and solved analytically and the parameters of the proposed model were determined using laboratory data analysis. The optimal values of the model parameters including coefficient <em>a</em> and the order of fractional derivative α, which can be varied in the range of (0-2), were calculated for each laboratory data set. The results were compared with the experimental data and the analytical solution of Izbash equation and a good agreement was found to the non-Darcian flow laboratory data. Moreover, using dimensional analysis method, Reynolds number was introduced as an effective factor on α coefficient and a suitable relationship was observed between the order of fractional derivative α and Reynolds number indicating the hydraulic concept of fractional-order model. According to the present study, the fractional order α is not only a fitting coefficient, but it represents a physical concept.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Comparison of Some Methods for Measuring Primary Soil Particle Size Distribution and Introducing Appropriate Times for the Four-Reading Method for Determining Soil TextureComparison of Some Methods for Measuring Primary Soil Particle Size Distribution and Introducing Appropriate Times for the Four-Reading Method for Determining Soil Texture299930158042910.22059/ijswr.2020.310061.668738FAMortazaYavariM.Sc. Student, Dep. of Soil Sciences and Engineering, Faculty of Engineering and Technology, University of Tehran, Karaj, IranMohammad HoseinMohammadiAssociate Professor Dep. of Soil Sciences and Engineering, Faculty of Engineering and Technology, University of Tehran, Karaj, Iran0000-0003-0596-7539KarimShahbazi,Research Associate Professor, Soil and Water Research Institute, AREEO, Karaj, Iran0000-0001-7994-2559Journal Article20200915Different methods are used for determination of the primary particle size distribution (PSD) in Iranian soils laboratories, which in many situations makes it difficult to compare results and their precision. This research was conducted to achieve an easy and inexpensive strategy with acceptable accuracy. First, 112 soil samples from 16 different provinces of Iran with a wide range of soils were taken from different climates and land uses. Soil PSD was measured by hydrometer with and without cement removal. The results showed that the common reading method of 40 seconds and 2 hours (Bouyoucos, 1962) measures the clay fraction with an average absolute error of 9.5% as compared to the complete record method. This error was more than 10% in 40.5% of the proposed soils and more than 5% in 94.2% of the soils. The deviation of this method from the actual value is increased as the soil becomes finer. Two four-reading methods with the classification of International Soil Science Association (ISSS) including: a) 2 and 10 minute readings (to measure silt fraction) and 6 and 8 hours (to measure clay fraction), and b) readings of 2 and 10 minutes (to measure silt fraction) and 6 and 24 hours (to measure clay fraction) were suggested to determine the soil texture. The two later methods show the soil texture correctly in 97.1 and 94.2% of the soils, respectively. The error of these two methods for determination of clay fraction is less than % in more than 90 and 81% of the proposed soils, respectively.Different methods are used for determination of the primary particle size distribution (PSD) in Iranian soils laboratories, which in many situations makes it difficult to compare results and their precision. This research was conducted to achieve an easy and inexpensive strategy with acceptable accuracy. First, 112 soil samples from 16 different provinces of Iran with a wide range of soils were taken from different climates and land uses. Soil PSD was measured by hydrometer with and without cement removal. The results showed that the common reading method of 40 seconds and 2 hours (Bouyoucos, 1962) measures the clay fraction with an average absolute error of 9.5% as compared to the complete record method. This error was more than 10% in 40.5% of the proposed soils and more than 5% in 94.2% of the soils. The deviation of this method from the actual value is increased as the soil becomes finer. Two four-reading methods with the classification of International Soil Science Association (ISSS) including: a) 2 and 10 minute readings (to measure silt fraction) and 6 and 8 hours (to measure clay fraction), and b) readings of 2 and 10 minutes (to measure silt fraction) and 6 and 24 hours (to measure clay fraction) were suggested to determine the soil texture. The two later methods show the soil texture correctly in 97.1 and 94.2% of the soils, respectively. The error of these two methods for determination of clay fraction is less than % in more than 90 and 81% of the proposed soils, respectively.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Evaluation of the Effect of Bias Correction Methods on the Skill of Seasonal Precipitation Forecasts of CFSv2 Climate ModelEvaluation of the Effect of Bias Correction Methods on the Skill of Seasonal Precipitation Forecasts of CFSv2 Climate Model301730328043010.22059/ijswr.2020.306717.668680FAFatemehShabanpourIrrigation and Reclamation Engineering Department, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, Karaj, IranJavadBazrafshanAssociate Professor, Irrigation and Reclamation Engineering Department, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran0000-0002-6721-8990ShahabAraghinejadAssociate Professor,Irrigation and Reclamation Engineering Department, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, Karaj, IranJournal Article20200730Bias correction methods are one of the most common statistical post-processing methods which are utilized on the output of climate models. This study evaluates the effect of five bias correction methods on the skill of seasonal precipitation forecast (fall season) from the CFSv2 climate model based on 12 stations located in Gorganrud basin in Iran. Bias correction methods that have been used in this study consists of two non-parametric methods (Linear Scaling (LS), Empirical Quantile Mapping (EQM)), one parametric method (Power Transformation (Ptr)), and two parametric methods based on the statistical distribution (Parametric Quantile Mapping (PQM), Generalized Parametric Quantile Mapping (GPQM)). Various metrics have been used for evaluating the effects of these methods on the skill of seasonal precipitation forecast which consists of bias, Pearson correlation coefficient, ranked probability skill score (RPSS), and the relative operating curve skill score (ROCSS). The Results of this study revealed that most of bias correction methods decreased the biases of the raw forecasts. The effect of each bias correction method on the RPSS and ROCSS (below and above normal events) scores may vary based on location and time, and each method can improve or worsen these two scores based on location and time. The results of this study suggest that the evaluation of various bias correction methods and distinguishing the most suitable method based on the goal of each study would be helpful in the improvement of seasonal precipitation forecast skill.Bias correction methods are one of the most common statistical post-processing methods which are utilized on the output of climate models. This study evaluates the effect of five bias correction methods on the skill of seasonal precipitation forecast (fall season) from the CFSv2 climate model based on 12 stations located in Gorganrud basin in Iran. Bias correction methods that have been used in this study consists of two non-parametric methods (Linear Scaling (LS), Empirical Quantile Mapping (EQM)), one parametric method (Power Transformation (Ptr)), and two parametric methods based on the statistical distribution (Parametric Quantile Mapping (PQM), Generalized Parametric Quantile Mapping (GPQM)). Various metrics have been used for evaluating the effects of these methods on the skill of seasonal precipitation forecast which consists of bias, Pearson correlation coefficient, ranked probability skill score (RPSS), and the relative operating curve skill score (ROCSS). The Results of this study revealed that most of bias correction methods decreased the biases of the raw forecasts. The effect of each bias correction method on the RPSS and ROCSS (below and above normal events) scores may vary based on location and time, and each method can improve or worsen these two scores based on location and time. The results of this study suggest that the evaluation of various bias correction methods and distinguishing the most suitable method based on the goal of each study would be helpful in the improvement of seasonal precipitation forecast skill.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Field investigation on the Application of an Automatic Discharge Control Valve on Water Uniformity in a Tape Irrigation SystemField investigation on the Application of an Automatic Discharge Control Valve on Water Uniformity in a Tape Irrigation System303330438043110.22059/ijswr.2020.310802.668750FAFatemeTayebiWater and sciences Eng., Faculty of agriculture and natural resources, Imam Khomeini International University,, Qazvin, Iran.MohammadBijankhanWater and sciences Eng., Faculty of agriculture and natural resources, Imam Khomeini International University,, Qazvin, Iran.HadiRamezani EtedaliWater and sciences Eng., Faculty of agriculture and natural resources, Imam Khomeini International University,, Qazvin, Iran.0000-0002-4840-0201Journal Article20200927Tape irrigation systems have become popular due to water resources scarcity. Uniform water distribution in such systems is of great importance. In this study the application of an automatic discharge control valve is investigated in terms of water distribution uniformity of tape irrigation systems. To this end, control valves of the design discharges of 0.4 and 0.6 l/s were fabricated based on the current design methods. To study the effect of the automatic discharge control valve, variations of the water distribution uniformity in tapes and laterals were estimated in some field tests. The results indicated that the uniformity coefficient increases up to 93% at the tapes’ entrance. Finally, recommendations were provided to select a reliable tape length. It was found that a pressure increase of 2.5 times higher than the design value would result in tape failure. Therefore, correct tape length selection is of great importance to prevent any damages.Tape irrigation systems have become popular due to water resources scarcity. Uniform water distribution in such systems is of great importance. In this study the application of an automatic discharge control valve is investigated in terms of water distribution uniformity of tape irrigation systems. To this end, control valves of the design discharges of 0.4 and 0.6 l/s were fabricated based on the current design methods. To study the effect of the automatic discharge control valve, variations of the water distribution uniformity in tapes and laterals were estimated in some field tests. The results indicated that the uniformity coefficient increases up to 93% at the tapes’ entrance. Finally, recommendations were provided to select a reliable tape length. It was found that a pressure increase of 2.5 times higher than the design value would result in tape failure. Therefore, correct tape length selection is of great importance to prevent any damages.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Investigating the Effects of Portland Cement and Lime on Improving Glycerol-Contaminated ClayInvestigating the Effects of Portland Cement and Lime on Improving Glycerol-Contaminated Clay304530578043210.22059/ijswr.2020.308425.668706FAMohammadHajimohammadiDepartment of Civil Engineering, Faculty of Engineering, Kharazmi University, Karaj, IranHamidiAmirDepartment of Civil Engineering, Faculty of Engineering, Kharazmi university, Karaj, IranJournal Article20200909Soil contamination through petrochemical activities and leakage of organic hydrocarbon is not just an environmental problem and also can be considered as an important geotechnical issue. Adding amendment material is one of the most suitable and economical solutions to improve the geotechnical parameters of contaminated soil. In this study, the effect of Portland cement content (3, 6 and 9%) and lime content (10, 20 and 30%) on kaolinite clay contaminated with glycerol content (3, 6 and 9%) was investigated through an experimental program. For this purpose, the samples were prepared as mixtures of clean or glycerol-contaminated clay with different Portland cement and lime contents for 7 days curing time. Then, unconfined compressive strength (UCS) tests were conducted on the samples. The results showed a reduction of the strength of glycerol-contaminated kaolinite clay. The strength reduction increased with increase in degree of contamination. Based on the scanning electron microscopy (SEM) analysis, it was found that the presence of glycerol prevents the interaction between soil-cement particles. However, adding Portland cement and lime to uncontaminated and contaminated soil increased the strength. The rate of increase in UCS increased with Portland cement and lime content. Also, the results of soil improvement showed that the strength of soil-cement mixture containing 9% Portland cement is approximately equal to that of the soil mixed with 10% lime. In other contents, the degree of improvement was dependent to the applied cement content. The main reasons were polar behavior of glycerol and its dielectric constant. The results were also analyzed and proved using the images taken by SEM.Soil contamination through petrochemical activities and leakage of organic hydrocarbon is not just an environmental problem and also can be considered as an important geotechnical issue. Adding amendment material is one of the most suitable and economical solutions to improve the geotechnical parameters of contaminated soil. In this study, the effect of Portland cement content (3, 6 and 9%) and lime content (10, 20 and 30%) on kaolinite clay contaminated with glycerol content (3, 6 and 9%) was investigated through an experimental program. For this purpose, the samples were prepared as mixtures of clean or glycerol-contaminated clay with different Portland cement and lime contents for 7 days curing time. Then, unconfined compressive strength (UCS) tests were conducted on the samples. The results showed a reduction of the strength of glycerol-contaminated kaolinite clay. The strength reduction increased with increase in degree of contamination. Based on the scanning electron microscopy (SEM) analysis, it was found that the presence of glycerol prevents the interaction between soil-cement particles. However, adding Portland cement and lime to uncontaminated and contaminated soil increased the strength. The rate of increase in UCS increased with Portland cement and lime content. Also, the results of soil improvement showed that the strength of soil-cement mixture containing 9% Portland cement is approximately equal to that of the soil mixed with 10% lime. In other contents, the degree of improvement was dependent to the applied cement content. The main reasons were polar behavior of glycerol and its dielectric constant. The results were also analyzed and proved using the images taken by SEM.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Modeling Bed Load Transport through Vegetated Channels Using Conceptual Pseudo Fluid ModelModeling Bed Load Transport through Vegetated Channels Using Conceptual Pseudo Fluid Model305930708043310.22059/ijswr.2020.308104.668701FAHossienRiahi MadvarAssistant Professor, Department of Water Engineering, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran,0000-0003-0887-1217Journal Article20200813Bed load transport modeling in rivers and channels with vegetation over bed and banks is important. On the other hand, the complexity of bed load transport through vegetation and shortcoming of previous studies, declare the necessity of developing new models. Therefore, in the present study, the pseudo fluid model in combination with bed shear stress and resistance equation was used based on stochastic method of bed load transport. The developed model uses new definitions for dimensionless parameters of flow intensity and bed load rate that include vegetation properties with fluid and sediments. The calibration and verification of model results with experimental results showed that the model with R<sup>2</sup>=0.91 and RMSE=8.2 have accurate capability in modelling bed load transport through vegetation. The parametric analysis of vegetation features and comparing the results with previous equations showed the reduction of 45 and 68 % in absolute mean error in Mayer-Peter-Muler (R<sup>2</sup>=0.45, RMSE=231.9) and Parker (R<sup>2</sup>=0.75, RMSE=91.9) models, which indicates the superiority of developed model and the presented framework can be used in hydraulic analysis of sedimentation engineering in rivers.Bed load transport modeling in rivers and channels with vegetation over bed and banks is important. On the other hand, the complexity of bed load transport through vegetation and shortcoming of previous studies, declare the necessity of developing new models. Therefore, in the present study, the pseudo fluid model in combination with bed shear stress and resistance equation was used based on stochastic method of bed load transport. The developed model uses new definitions for dimensionless parameters of flow intensity and bed load rate that include vegetation properties with fluid and sediments. The calibration and verification of model results with experimental results showed that the model with R<sup>2</sup>=0.91 and RMSE=8.2 have accurate capability in modelling bed load transport through vegetation. The parametric analysis of vegetation features and comparing the results with previous equations showed the reduction of 45 and 68 % in absolute mean error in Mayer-Peter-Muler (R<sup>2</sup>=0.45, RMSE=231.9) and Parker (R<sup>2</sup>=0.75, RMSE=91.9) models, which indicates the superiority of developed model and the presented framework can be used in hydraulic analysis of sedimentation engineering in rivers.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219The Impact of Organic and Inorganic Amendments on Removal of Heavy Metals in Soils Polluted with Sewage SludgeThe Impact of Organic and Inorganic Amendments on Removal of Heavy Metals in Soils Polluted with Sewage Sludge307130858043410.22059/ijswr.2020.305018.668654FAGhasemRahimiAssistant Prof. Soil science, Faculty of Agriculture, Bu Ali Sina University. Hamadan0000-0002-5167-0667EisaEbrahimiPh. D. Student, Soil Science Department, Faculty of Agricultural Sciences, University of Guilan0000-0003-3394-2830Journal Article20200623Application of sewage sludge on agricultural fields may increase the risk of soil contamination with heavy metals and could affect distribution of heavy metals in soil. The application of amendment is essential in order to reduce the harmful effects of sewage sludge applied to the soil. This study aimed to investigate the impact of organic and inorganic amendments on removal of heavy metals in the soils contaminated through sewage sludge application. Firstly, the sewage sludge was applied to the soil at levels of 0, 10, 20, 30, 40 and 50 tons per hectare, which increased heavy metal concentrations in the soil. Then, earthworm (<em>Eisenia fetida</em>) was added to the polluted soil in order to study the effect of organic amendments. The total concentration and fractionation of heavy metals, the weight and mortality of earthworm were evaluated after 42 days. Nanoparticles of Aluminium oxide was applied to the soil in order to study the effect of inorganic amendments. Earthworm activity caused a reduction in the total amount of Copper, Zinc, Nickel and Cadmium, while led to an increase in the total amount of Lead. Earthworms decreased all metals except Cadmium in the exchangeable fraction. The residual fraction of Zinc and Copper increased whereas the residual fraction of other three elements decreased. The total concentrations of heavy metals were decreased as a result of the aluminum oxide nanoparticles treatment. Heavy metals for Lead and Cadmium in exchangeable fraction were reduced by nanoparticles of aluminum oxide. The amount of all metals was decreased for organic fraction. The Lead and Cadmium were decreased in inorganic and residual fractions whereas other elements were increased. In general, the use of earthworms can be more effective than nanoparticles. The use of nanoparticles is not economic, while the presence of earthworms as soil organisms is very cost-effective.Application of sewage sludge on agricultural fields may increase the risk of soil contamination with heavy metals and could affect distribution of heavy metals in soil. The application of amendment is essential in order to reduce the harmful effects of sewage sludge applied to the soil. This study aimed to investigate the impact of organic and inorganic amendments on removal of heavy metals in the soils contaminated through sewage sludge application. Firstly, the sewage sludge was applied to the soil at levels of 0, 10, 20, 30, 40 and 50 tons per hectare, which increased heavy metal concentrations in the soil. Then, earthworm (<em>Eisenia fetida</em>) was added to the polluted soil in order to study the effect of organic amendments. The total concentration and fractionation of heavy metals, the weight and mortality of earthworm were evaluated after 42 days. Nanoparticles of Aluminium oxide was applied to the soil in order to study the effect of inorganic amendments. Earthworm activity caused a reduction in the total amount of Copper, Zinc, Nickel and Cadmium, while led to an increase in the total amount of Lead. Earthworms decreased all metals except Cadmium in the exchangeable fraction. The residual fraction of Zinc and Copper increased whereas the residual fraction of other three elements decreased. The total concentrations of heavy metals were decreased as a result of the aluminum oxide nanoparticles treatment. Heavy metals for Lead and Cadmium in exchangeable fraction were reduced by nanoparticles of aluminum oxide. The amount of all metals was decreased for organic fraction. The Lead and Cadmium were decreased in inorganic and residual fractions whereas other elements were increased. In general, the use of earthworms can be more effective than nanoparticles. The use of nanoparticles is not economic, while the presence of earthworms as soil organisms is very cost-effective.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Improving the Estimation of Soil Cation Exchange Capacity Using Fractal DimensionsImproving the Estimation of Soil Cation Exchange Capacity Using Fractal Dimensions310230878043510.22059/ijswr.2020.308515.668711FAHasanMozaffariDepartment of Soil Science, College of Agriculture,, Shiraz University, Shiraz,, IranAli AkbarMoosaviDepartment of Soil Science, College of Agriculture,, Shiraz University, Shiraz,, Iran0000-0003-0305-2829FarnazAhmadiDepartment of Soil Science, College of Agriculture,, Shiraz University, Shiraz,, IranJournal Article20200819Cation exchange capacity (CEC) is one of the most important soil chemical properties in terms of plant nutrition and pollutants adsorption in soil that its measurement is time-consuming and expensive. Therefore, this study aimed to estimate soil CEC using values of organic matter, soil textural components, and Tyler and Wheatcraft (D<sub>T</sub>) and Sepaskhah and Tafteh (D<sub>S</sub>) fractal dimensions and also to investigate the efficiency of mentioned fractal dimensions as an independent variable and its effect on the accuracy of regression relationships to estimate soil CEC. In this study, data from 100 soil samples of UNSODA soil database were used. Soil primary particles size distribution was calculated using the Skaggs approach and fractal dimension of soil primary particles was calculated using the Sepaskhah and Tafteh and Tyler and Wheatcraft approaches. Results showed that the CEC values had significant negative relationship with sand content, and significant positive relationship with logarithm (in base 10) of organic matter, clay, D<sub>S</sub> and D<sub>T</sub> values. Values of training and test data determination coefficients, normalized root mean square error (%) and Nash-Sutcliffe coefficient for multivariate regression relationship between CEC versus logarithm (in base 10) of organic matter and clay were respectively equal to 0.77, 0.84, 17.2 and 0.92; between CEC versus logarithm (in base 10) of organic matter and D<sub>S</sub> were respectively equal to 0.77, 0.85, 17.2 and 0.92 and between CEC versus logarithm (in base 10) of organic matter and D<sub>T</sub> were respectively equal to 0.77, 0.87, 14.0 and 0.93. Therefore, the most accuracy of regression relationships to estimate CEC obtained when organic matter and D<sub>T</sub> variables was used as independent variables. In other words, application of D<sub>T </sub>improved CEC estimation.Cation exchange capacity (CEC) is one of the most important soil chemical properties in terms of plant nutrition and pollutants adsorption in soil that its measurement is time-consuming and expensive. Therefore, this study aimed to estimate soil CEC using values of organic matter, soil textural components, and Tyler and Wheatcraft (D<sub>T</sub>) and Sepaskhah and Tafteh (D<sub>S</sub>) fractal dimensions and also to investigate the efficiency of mentioned fractal dimensions as an independent variable and its effect on the accuracy of regression relationships to estimate soil CEC. In this study, data from 100 soil samples of UNSODA soil database were used. Soil primary particles size distribution was calculated using the Skaggs approach and fractal dimension of soil primary particles was calculated using the Sepaskhah and Tafteh and Tyler and Wheatcraft approaches. Results showed that the CEC values had significant negative relationship with sand content, and significant positive relationship with logarithm (in base 10) of organic matter, clay, D<sub>S</sub> and D<sub>T</sub> values. Values of training and test data determination coefficients, normalized root mean square error (%) and Nash-Sutcliffe coefficient for multivariate regression relationship between CEC versus logarithm (in base 10) of organic matter and clay were respectively equal to 0.77, 0.84, 17.2 and 0.92; between CEC versus logarithm (in base 10) of organic matter and D<sub>S</sub> were respectively equal to 0.77, 0.85, 17.2 and 0.92 and between CEC versus logarithm (in base 10) of organic matter and D<sub>T</sub> were respectively equal to 0.77, 0.87, 14.0 and 0.93. Therefore, the most accuracy of regression relationships to estimate CEC obtained when organic matter and D<sub>T</sub> variables was used as independent variables. In other words, application of D<sub>T </sub>improved CEC estimation.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219The Effect of Different Levels of Silicon from a Source of Silicic Acid on Aloe vera L. Growth Traits under Cold StressThe Effect of Different Levels of Silicon from a Source of Silicic Acid on Aloe vera L. Growth Traits under Cold Stress310331138043610.22059/ijswr.2020.301196.668582FASeyed PeymanAzarfamDepartment of Soil Science, Faculty of Agriculture , Islamic Azad University, Ahvaz, Iran.HabiballahNadian GhomshehProfessor,Department of Soil Science, Agricultural Science and Natural Resources University of Khuzestan, Ahvaz, IranAbdolamirMoezziAssociate Professor, Department of Soil Science, Shahid Chamran University of Ahvaz,. Iran.0000-0003-1738-8825AliGholamiDepartment of Soil Science, Faculty of Agriculture , Islamic Azad University, Ahvaz, Iran.Journal Article20200507Due to the importance of useful elements such as silicon in improving plant resistance to environmental and biological stresses, a factorial experiment was conducted in a completely randomized design in Hashtgerd city, hydroponic greenhouse No. 256. Experimental factors included temperature at 4°C (stress temperature) and 25°C (optimum growth temperature) and application of silicon fertilizer from source of silicic acid at five levels; 0, 500, 1000, 1500 and 2000 mg/kg with three replications, in total 30 pots. The measured traits included the activity of superoxide dismutase (SOD), catalase (CAT), antioxidant enzymes and the qualitative characteristics of aloe vera consist of Mannose, Glucomannan and Aloin concentrations and the plant growth characteristics including aloe vera gel and leaf weight, which were tested at 4<sup>°</sup>C as cold stress temperature and 25<sup>°</sup>C as the optimum growth temperature of the plant. The obtained results after applying cold stress showed that the effect of silicon fertilizer levels applied on (SOD) and (CAT) and Glucomannan and Mannose activities were significant at 1% level. It was also observed that the interaction of different concentrations of silicon fertilizer and temperature stress is significant at 1% level on all compounds. For vegetative and biochemical traits, the highest interaction was observed in treatment of 2000 mg/kg silicic asid fertilizer at 25°C. For antioxidants, the highest interaction was found in treatment of 2000 mg/kg silicic acid and stress temperature of 4°C. Therefore, the application of 2000 mg/kg pure silicon could have positive effects on the activity of antioxidant enzymes and vegetative traits at normal temperature and a more favorable effect on biochemical traits under temperature stress. Consequently, the silicium fertilizer can be applied as a useful and suitable element in ncreasing the quantity and quality of aloe vera plant.Due to the importance of useful elements such as silicon in improving plant resistance to environmental and biological stresses, a factorial experiment was conducted in a completely randomized design in Hashtgerd city, hydroponic greenhouse No. 256. Experimental factors included temperature at 4°C (stress temperature) and 25°C (optimum growth temperature) and application of silicon fertilizer from source of silicic acid at five levels; 0, 500, 1000, 1500 and 2000 mg/kg with three replications, in total 30 pots. The measured traits included the activity of superoxide dismutase (SOD), catalase (CAT), antioxidant enzymes and the qualitative characteristics of aloe vera consist of Mannose, Glucomannan and Aloin concentrations and the plant growth characteristics including aloe vera gel and leaf weight, which were tested at 4<sup>°</sup>C as cold stress temperature and 25<sup>°</sup>C as the optimum growth temperature of the plant. The obtained results after applying cold stress showed that the effect of silicon fertilizer levels applied on (SOD) and (CAT) and Glucomannan and Mannose activities were significant at 1% level. It was also observed that the interaction of different concentrations of silicon fertilizer and temperature stress is significant at 1% level on all compounds. For vegetative and biochemical traits, the highest interaction was observed in treatment of 2000 mg/kg silicic asid fertilizer at 25°C. For antioxidants, the highest interaction was found in treatment of 2000 mg/kg silicic acid and stress temperature of 4°C. Therefore, the application of 2000 mg/kg pure silicon could have positive effects on the activity of antioxidant enzymes and vegetative traits at normal temperature and a more favorable effect on biochemical traits under temperature stress. Consequently, the silicium fertilizer can be applied as a useful and suitable element in ncreasing the quantity and quality of aloe vera plant.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Investigation of Different Levels of Irrigation on Yield and Water Use Efficiency of Stevia Rebaudiana Bertoni in Greenhouse and Field Environment ConditionsInvestigation of Different Levels of Irrigation on Yield and Water Use Efficiency of Stevia Rebaudiana Bertoni in Greenhouse and Field Environment Conditions311531258043710.22059/ijswr.2020.308735.668716FAHoushangGhamarniaWater Engineering Dept, Faculty of Agricultural Science and Engineering, Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran0000-0003-2106-1075ZahraJaliliWater Engineering Department, Faculty of Agricultural Sciences and Engineering, Campus of Agriculture and Natural Resources, Razi University, Kermanshah, IranSeyed VahidoddinRezvaniWater Engineering Department, Faculty of Agriculture Engineering, University of Kurdistan, Sanandaj, IranJournal Article20200823Iran, with a mean precipitation of 230 mm per year, is classified as arid and semi-arid region in the world, facing a water crisis. Since, water resources with high quality for irrigation are limited, therefore the use of deficit irrigation as a method for reducing water consumption is essential in the future. Stevia is a plant with medicinal and anti-diabetic effects, native to the mountainous region of Amoeba, located on the border of Brazil and Paraguay, which is widely cultivated in Shiraz and Isfahan of Iran. The diterpene glycosides in this plant (the main cause of the very sweet taste in plant extracts) are up to 300 times sweeter than sugar used in the pharmaceutical and food industries. In the present study, different treatments consist of 40, 60, 80 and 100% of total crop water requirement were carried out to investigate the effects of different water shortage on (<em>Stevia Rebaudiana B</em>.). This experiment was performed in three replications in the greenhouse and farm environment condition in 2016 and 2017.The results showed that the tolerance threshold of stevia in low irrigation to prevent reduced leaf and sugar yield in the greenhouse environment was about (3.2 and 3.1) and (0.94 and 0.83) and in the farm condition was obtained as: (3.3 and 3.1) and (1.12 and 0.98) of defecit irrigation percentage in the first and second year of cultivation respectively.Iran, with a mean precipitation of 230 mm per year, is classified as arid and semi-arid region in the world, facing a water crisis. Since, water resources with high quality for irrigation are limited, therefore the use of deficit irrigation as a method for reducing water consumption is essential in the future. Stevia is a plant with medicinal and anti-diabetic effects, native to the mountainous region of Amoeba, located on the border of Brazil and Paraguay, which is widely cultivated in Shiraz and Isfahan of Iran. The diterpene glycosides in this plant (the main cause of the very sweet taste in plant extracts) are up to 300 times sweeter than sugar used in the pharmaceutical and food industries. In the present study, different treatments consist of 40, 60, 80 and 100% of total crop water requirement were carried out to investigate the effects of different water shortage on (<em>Stevia Rebaudiana B</em>.). This experiment was performed in three replications in the greenhouse and farm environment condition in 2016 and 2017.The results showed that the tolerance threshold of stevia in low irrigation to prevent reduced leaf and sugar yield in the greenhouse environment was about (3.2 and 3.1) and (0.94 and 0.83) and in the farm condition was obtained as: (3.3 and 3.1) and (1.12 and 0.98) of defecit irrigation percentage in the first and second year of cultivation respectively.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219The Effect of Drip Strips Irrigation (Tape) on Physical and Economic Productivity of Paddy Fields in Sari CityThe Effect of Drip Strips Irrigation (Tape) on Physical and Economic Productivity of Paddy Fields in Sari City312731348043810.22059/ijswr.2020.307913.668698FAGhasemGholinezhadDepartment of water Engineering, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.Mohammad AliGholami SefidkouhiWater Engineering, sari agricultural sciences natural resources university0000-0001-8732-4929Seyyed YousefMosaviDepartment of Agronomy, Faculty of Agronomy Sciences, Sari Agricultural Sciences and Natural Resources UniversityJournal Article20200809Population growth, climate change and improper management, have caused a water shortage crisis in the world and especially in Iran. So it is necessary to change attitudes in irrigation management from the emphasis on production per unit area to maximize production per unit of water consumption. The aim of this study was to investigate and evaluate the effect of localized irrigation tape (TIP) on water productivity (CPD) and water economic productivity (NBPD) in paddy fields. The experiment was carried out as a split plot design with three replications in 2019-2020 crop year. In this experiment, the main factor was irrigation method including flood irrigation (FI) and three levels of deficit irrigation; 25, 50 and 100 cm tape space (TP25, TP50, TP100) and the sub-factor was two rice cultivars; Amir and Fajr. Results showed that the highest values of CPD of water consumption and water delivery and NBPD were corresponded to TP25 irrigation treatment for both cultivars. The highest CPD of water consumption was 0.66 and 0.94 kg/m<sup>3</sup> in Amir and Fajr cultivars, respectively, and the highest CPD of irrigation water was 0.74 and 1.07 kg/m<sup>3</sup> in Amir and Fajr cultivars, respectively. Also, the highest NBPD in Amir and Fajr cultivars were 32107 and 40852 Rials per cubic meter, respectively. The TP25 irrigation treatment increased NBPD in Amir and Fajr cultivars 36 and 63%, respectively. Also, in average about 4500 cubic meters per hectare of water will be saved annually. Therefore, this irrigation treatment increases water productivity of water consumption and water delivery and also economic benefits in both cultivars.Population growth, climate change and improper management, have caused a water shortage crisis in the world and especially in Iran. So it is necessary to change attitudes in irrigation management from the emphasis on production per unit area to maximize production per unit of water consumption. The aim of this study was to investigate and evaluate the effect of localized irrigation tape (TIP) on water productivity (CPD) and water economic productivity (NBPD) in paddy fields. The experiment was carried out as a split plot design with three replications in 2019-2020 crop year. In this experiment, the main factor was irrigation method including flood irrigation (FI) and three levels of deficit irrigation; 25, 50 and 100 cm tape space (TP25, TP50, TP100) and the sub-factor was two rice cultivars; Amir and Fajr. Results showed that the highest values of CPD of water consumption and water delivery and NBPD were corresponded to TP25 irrigation treatment for both cultivars. The highest CPD of water consumption was 0.66 and 0.94 kg/m<sup>3</sup> in Amir and Fajr cultivars, respectively, and the highest CPD of irrigation water was 0.74 and 1.07 kg/m<sup>3</sup> in Amir and Fajr cultivars, respectively. Also, the highest NBPD in Amir and Fajr cultivars were 32107 and 40852 Rials per cubic meter, respectively. The TP25 irrigation treatment increased NBPD in Amir and Fajr cultivars 36 and 63%, respectively. Also, in average about 4500 cubic meters per hectare of water will be saved annually. Therefore, this irrigation treatment increases water productivity of water consumption and water delivery and also economic benefits in both cultivars.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Effect of Pulsed Management in Drip Irrigation on Yield, Yield Components and Water Productivity of Silage MaizeEffect of Pulsed Management in Drip Irrigation on Yield, Yield Components and Water Productivity of Silage Maize313531458043910.22059/ijswr.2020.309258.668726FASanazMohammadiWater management and engineering Department, Collage of Agriculture, Tarbiat Modares University, Tehran, Iran0000-0002-3347-4777MajidMirlatifiWater Management and Engineering Department, Collage of Agriculture, Tarbiat Modares University, Tehran, Iran0000-0002-3828-5625HosseinDehghanisanijAssociate Researcher, Agricultural Engineering Research Institute, Agricultural Research, Education and Extension Organization, Karaj, Alborz, Iran0000-0002-5617-9375MehdiHomaeeWater Management and Engineering Department, Collage of Agriculture, Tarbiat Modares University, Tehran, Iran0000-0000-0000-0000Journal Article20200911Water scarcity across the world has led researchers to develop a new irrigation technique called pulsed drip irrigation in order to improve soil moisture distribution as well as to increase water productivity. Pulsed drip irrigation refers to irrigating for a short period then waiting for another short period and repeating this On-Off cycle until the entire irrigation depth is applied. In this study, the combined effects of pulsed drip irrigation and its On-Off time duration on yield, yield components and water productivity of silage maize under two growing seasons (spring and summer) were evaluated. The selected experimental design was split-plot in completely randomized block design with three replicates. The treatments were consisted of four pulsed drip irrigations (P1, P2, P3, P4) and two Off-Time duration, 1 and 3 times of On-Time duration in a pulse (T1, T2). Results indicated that the interaction of the studied treatments on yield, yield components and water productivity of silage maize is significant. The maximum dry yield and water productivity was 25.86 (ton/ha) and 5.95 (kg/m<sup>3</sup>) in (T2 P4) treatment (average of two growing seasons) which increased by about 17% compared to (T1 P1) treatment. Increasing the number of irrigation pulses to four times lead to 6% and 17% increase in the studied parameters, respectively, in T1 and T2 treatments. Consequently, based on the positive effect of increasing the Off-Time duration in applying pulsed drip irrigation with high flow rate, it is suggested that the ratio of Off-Time to On-Time duration should be increased.Water scarcity across the world has led researchers to develop a new irrigation technique called pulsed drip irrigation in order to improve soil moisture distribution as well as to increase water productivity. Pulsed drip irrigation refers to irrigating for a short period then waiting for another short period and repeating this On-Off cycle until the entire irrigation depth is applied. In this study, the combined effects of pulsed drip irrigation and its On-Off time duration on yield, yield components and water productivity of silage maize under two growing seasons (spring and summer) were evaluated. The selected experimental design was split-plot in completely randomized block design with three replicates. The treatments were consisted of four pulsed drip irrigations (P1, P2, P3, P4) and two Off-Time duration, 1 and 3 times of On-Time duration in a pulse (T1, T2). Results indicated that the interaction of the studied treatments on yield, yield components and water productivity of silage maize is significant. The maximum dry yield and water productivity was 25.86 (ton/ha) and 5.95 (kg/m<sup>3</sup>) in (T2 P4) treatment (average of two growing seasons) which increased by about 17% compared to (T1 P1) treatment. Increasing the number of irrigation pulses to four times lead to 6% and 17% increase in the studied parameters, respectively, in T1 and T2 treatments. Consequently, based on the positive effect of increasing the Off-Time duration in applying pulsed drip irrigation with high flow rate, it is suggested that the ratio of Off-Time to On-Time duration should be increased.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Kinetics of Arsenic Adsorption on Some Soils: The Effect of Competing Anions and Comparison of Kinetic ModelsKinetics of Arsenic Adsorption on Some Soils: The Effect of Competing Anions and Comparison of Kinetic Models314731597817410.22059/ijswr.2020.310210.668739FAArzhangFathi GerdelidaniPh.D Student, Department of Soil Science and Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Iran0000-0002-8840-2009HasanTowfighiAssociate Professor, Soil Science Department, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, IranKarimShahbaziResearch Associate Professor, Soil and Water Research Institute, AREEO, Karaj, Iran0000-0001-7994-2559Journal Article20200919Arsenic adsorption on soils plays an important role in controlling mobility, bioavailability and toxicity of arsenic in the environment. Kinetic studies on arsenic adsorption are often done at soil to water ratios of 1:10 to 1:50, which generally make the conditions of the study different from the prevailing field situations. In this study, kinetics of arsenic adsorption were investigated in five arsenic-uncontaminated agricultural soils at saturation moisture content of 50% over long periods of time (2 minutes to 20 days). Six kinetic models were fitted to the data. The kinetics of arsenic adsorption on soils were nonlinear and biphasic. Arsenic adsorption rates were initially rapid, but gradually decreased with time and reached a plateau after 72 hours. The cumulative amount of arsenic adsorbed by soils ranged from 158 to 210 mg/kg, 47-67% of it was adsorbed in the first two minutes (the first measurement time) and 68-86% of it was adsorbed in the first hour of the reaction. Cumulative adsorption of arsenic on different soils was reduced by 1.9-16% in the presence of 100 mM phosphate, 0.7-9% in the presence of 100 mM citrate and 0.6-9% in the presence of 10 mM phosphate as compared to arsenic adsorption alone. The simplified Elovich model with the higher coefficients of determination ( ) values (0.93-0.96) and lower standard errors of the estimate values (5.1-6.5 mg/kg) best described arsenic adsorption data in all soils compared to zero-, first-, and second-order, power function and parabolic diffusion models.Arsenic adsorption on soils plays an important role in controlling mobility, bioavailability and toxicity of arsenic in the environment. Kinetic studies on arsenic adsorption are often done at soil to water ratios of 1:10 to 1:50, which generally make the conditions of the study different from the prevailing field situations. In this study, kinetics of arsenic adsorption were investigated in five arsenic-uncontaminated agricultural soils at saturation moisture content of 50% over long periods of time (2 minutes to 20 days). Six kinetic models were fitted to the data. The kinetics of arsenic adsorption on soils were nonlinear and biphasic. Arsenic adsorption rates were initially rapid, but gradually decreased with time and reached a plateau after 72 hours. The cumulative amount of arsenic adsorbed by soils ranged from 158 to 210 mg/kg, 47-67% of it was adsorbed in the first two minutes (the first measurement time) and 68-86% of it was adsorbed in the first hour of the reaction. Cumulative adsorption of arsenic on different soils was reduced by 1.9-16% in the presence of 100 mM phosphate, 0.7-9% in the presence of 100 mM citrate and 0.6-9% in the presence of 10 mM phosphate as compared to arsenic adsorption alone. The simplified Elovich model with the higher coefficients of determination ( ) values (0.93-0.96) and lower standard errors of the estimate values (5.1-6.5 mg/kg) best described arsenic adsorption data in all soils compared to zero-, first-, and second-order, power function and parabolic diffusion models.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Assessment of Soil Quality in Paddy Soils with Different Yields (A Case Study: Kouchsfahan, Guilan Province)Assessment of Soil Quality in Paddy Soils with Different Yields (A Case Study: Kouchsfahan, Guilan Province)316131767855610.22059/ijswr.2020.305420.668660FAMaryamShakouriPhD student, Department of Soil Science, Faculty of Agricultural Science, University of Guilan0000-0001-7764-9578MahmoudShabanpourDepartment of Soil Science, Faculty of Agricultural Science, University of Guilan0000-0003-0862-7804NaserDavatgarSoil and Water Research Institute, Agricultural Research, Education and Extension Organization (AREEO),0000-0002-1872-9815MajidVazifehdoustAssistant professor, Department of Water Engineering, Faculty of Agricultural Science, University of Guilan,Journal Article20200630Rapid growth of population, followed by increasing food demand, necessitates knowledge of the relationship between yield and soil conditions. The soil quality index (SQI) is one of the indicators showing the soil conditions and the related properties very well.This study was performed to determine the effect of soil quality on rice yield in north of Iran (Gilan province). 64 soil samples from rice fields were prepared to measure the physical and chemical properties affecting soil quality and also the yield of rice in the mentioned fields were determined using plot. Then the total yields were divided into three classes with yields of less than 4000 kg/ha (first class), 4000-4500 kg/ha (second class) and more than 4500 kg/ha (third class). Among the studied properties, 16 properties as selected indicators of total data method (TDS) and five properties using principal component analysis as selected indicators of minimum data set method (MDS) were selected to determine the soil quality index. Fuzzy logic was used for scoring and the concept of communality index was used to weight the indicators and finally they were combined using weighted additive method. The results of quality index showed a positive and high correlation between TDS and MDS methods (R2 = 0.87). The results of correlation coefficient between yield and SQI by TDS method (R2 = 0.52) were higher than the SQI by MDS method (R2 = 0.28). In the MDS method, simmilar to TDS method, there was an increasing trend in the SQI value of higher yield classes, but there is no significant difference between the second and third classes. The difference between soil quality and lower yields with MDS method is significant, but this difference is not significant at higher yield levels, because as the number of indicators decreases, the accuracy and sensitivity of soil quality assessment decreases.Rapid growth of population, followed by increasing food demand, necessitates knowledge of the relationship between yield and soil conditions. The soil quality index (SQI) is one of the indicators showing the soil conditions and the related properties very well.This study was performed to determine the effect of soil quality on rice yield in north of Iran (Gilan province). 64 soil samples from rice fields were prepared to measure the physical and chemical properties affecting soil quality and also the yield of rice in the mentioned fields were determined using plot. Then the total yields were divided into three classes with yields of less than 4000 kg/ha (first class), 4000-4500 kg/ha (second class) and more than 4500 kg/ha (third class). Among the studied properties, 16 properties as selected indicators of total data method (TDS) and five properties using principal component analysis as selected indicators of minimum data set method (MDS) were selected to determine the soil quality index. Fuzzy logic was used for scoring and the concept of communality index was used to weight the indicators and finally they were combined using weighted additive method. The results of quality index showed a positive and high correlation between TDS and MDS methods (R2 = 0.87). The results of correlation coefficient between yield and SQI by TDS method (R2 = 0.52) were higher than the SQI by MDS method (R2 = 0.28). In the MDS method, simmilar to TDS method, there was an increasing trend in the SQI value of higher yield classes, but there is no significant difference between the second and third classes. The difference between soil quality and lower yields with MDS method is significant, but this difference is not significant at higher yield levels, because as the number of indicators decreases, the accuracy and sensitivity of soil quality assessment decreases.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Effects of Enriched Biochars on the Availability and Fractions of Phosphorus in the Saline Soils of Lake Urmia BasinEffects of Enriched Biochars on the Availability and Fractions of Phosphorus in the Saline Soils of Lake Urmia Basin317731937858010.22059/ijswr.2020.294590.668438FARoghayehMousaviDepartment of Soil Science, Faculty of Agriculture, Urmia University, Urmia, IranMirHassanRasouli-SadaghianiDepartment of Soil Science, Faculty of Agricultre, Urmia University, Urmia, Iran0000-0001-9804-4076EbrahimSepehrDepartment of Soil Science, Faculty of Agricultre, Urmia University, Urmia, Iran0000-0001-5843-0669MohsenBarinDepartment of Soil Science, Faculty of Agriculture, Urmia University, Urmia, IranMaryamKhezriDepartment of Plant Protection, Faculty of Agriculture, Urmia University, Urmia, IranJournal Article20191223In order to reduce the problems of biochar application in calcareous soils, by changing the surface properties of apple-grape biochar by phosphoric and chloric acids, the effects of enriched biochars on the fraction of phosphorus (P) forms in saline soils of Lake Urmia was investigated as a factorial incubation experiment in a completely randomized design with two factors: fertilizer treatments (control (Cont), biochar (BC), phosphate fertilizer (TSP), Biochar-Rock phosphate (BC-RP) and enriched-biochar (EB) types (BC-HCl-RP and BC-H<sub>3</sub>PO<sub>4</sub>-RP)) and 2 calcareous soils with different EC (2 and 15 dSm<sup>-1</sup>). Olsen-P, pH and different forms of inorganic P were determined by sequential extraction method at 7, 30 and 60 days of incubation. The results showed that on average, the BC-HCl-RP and BC-H<sub>3</sub>PO<sub>4</sub>-RP treatments reduced the pH of S1and S2 soils, 0.5 and 1 unit, respectively. BC-H<sub>3</sub>PO<sub>4</sub>-RP and BC-HCl-RP treatments increased Olsen-P of S1 soil from 6.7 to 57.5 and 55.5 mgkg-1 and soil S2 from 7.4 mgkg-1 to 71.3 and 62 mgkg-1, respectively. Enriched biochars significantly (p <0.01) altered the distribution and amount of inorganic P forms. Thus, BC-H<sub>3</sub>PO<sub>4</sub>-RP and BC-HCl-RP treatments increased the amount of Ca<sub>2</sub>-P fraction in the S1 soil by 2.9 and 2.6 times and in the S2 soils by 1.06 and 0.97 times, respectively. However, the amounts of Ca<sub>8</sub>-P, Al –P and Ca<sub>10</sub>-P fractions reduced significantly. Olsen-P positively and significantly correlated with Ca<sub>2</sub>-P, Fe-P, and Ca<sub>10</sub>-P fractions and positively but not significantly with the Al-P fraction, suggesting that in the extraction of Olsen-P, phosphorus is released from these mineral fractions. In general, EBs application may cause P to remain in the plant-available forms over the time. Therefore, it can help to improve P nutrition, reduce salinity stress, and eliminate the common problems of biochar application in these soils.In order to reduce the problems of biochar application in calcareous soils, by changing the surface properties of apple-grape biochar by phosphoric and chloric acids, the effects of enriched biochars on the fraction of phosphorus (P) forms in saline soils of Lake Urmia was investigated as a factorial incubation experiment in a completely randomized design with two factors: fertilizer treatments (control (Cont), biochar (BC), phosphate fertilizer (TSP), Biochar-Rock phosphate (BC-RP) and enriched-biochar (EB) types (BC-HCl-RP and BC-H<sub>3</sub>PO<sub>4</sub>-RP)) and 2 calcareous soils with different EC (2 and 15 dSm<sup>-1</sup>). Olsen-P, pH and different forms of inorganic P were determined by sequential extraction method at 7, 30 and 60 days of incubation. The results showed that on average, the BC-HCl-RP and BC-H<sub>3</sub>PO<sub>4</sub>-RP treatments reduced the pH of S1and S2 soils, 0.5 and 1 unit, respectively. BC-H<sub>3</sub>PO<sub>4</sub>-RP and BC-HCl-RP treatments increased Olsen-P of S1 soil from 6.7 to 57.5 and 55.5 mgkg-1 and soil S2 from 7.4 mgkg-1 to 71.3 and 62 mgkg-1, respectively. Enriched biochars significantly (p <0.01) altered the distribution and amount of inorganic P forms. Thus, BC-H<sub>3</sub>PO<sub>4</sub>-RP and BC-HCl-RP treatments increased the amount of Ca<sub>2</sub>-P fraction in the S1 soil by 2.9 and 2.6 times and in the S2 soils by 1.06 and 0.97 times, respectively. However, the amounts of Ca<sub>8</sub>-P, Al –P and Ca<sub>10</sub>-P fractions reduced significantly. Olsen-P positively and significantly correlated with Ca<sub>2</sub>-P, Fe-P, and Ca<sub>10</sub>-P fractions and positively but not significantly with the Al-P fraction, suggesting that in the extraction of Olsen-P, phosphorus is released from these mineral fractions. In general, EBs application may cause P to remain in the plant-available forms over the time. Therefore, it can help to improve P nutrition, reduce salinity stress, and eliminate the common problems of biochar application in these soils.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Effect of Soil Texture and Different Levels of Irrigation Amount on Water Requirement and Crop Coefficient of Melia azedarach L. in Karaj AreaEffect of Soil Texture and Different Levels of Irrigation Amount on Water Requirement and Crop Coefficient of Melia azedarach L. in Karaj Area319532057837010.22059/ijswr.2020.303336.668627FAKhaledAhmadaaliDepartment of Arid and Mountainous Regions Reclamation, Faculty of natural resources, University of Tehran, Karaj, IranHosseinRahimiDepartment of Forestry and Forest Economics, Faculty of natural resources, University of Tehran, Karaj, IranVahidEtemadDepartment of Forestry and Forest Economics, Faculty of natural resources0000-0001-6560-7653Journal Article20200531The growing population, the need to develop urban green space, water resources scarcity and the competition between different sectors of water consumption have necessitated to determine the accurate crop water requirement of different species in green spaces. In this study, a factorial experiment with two factors (soil texture and drought stress) was conducted to determine evapotranspiration (ETc) and crop coefficient (Kc) of <em>Melia azedarach L</em>. using microlysimeters based on a randomized complete block design (RCBD) with 10 replications. This study was performed in the climatic conditions of Karaj during 2019-2020. Soil texture consisted of clay loam and sandy loam and drought stress levels consisted of 0.3, 0.5, and 0.7 of management allowed depletion (MAD). The results showed that the 10-day ETc under 0.3, 0.5, and 0.7 MAD were 15.35, 13.81 and 12.63 mm in clay loam and they were 19.35, 16.9 and 16.58 mm in sandy loam soil, respectively. In both clay loam and sandy loam soils, the ETc decreased as drought stress increased. During the growing season, total net water requirement of <em>Melia azedarach </em>L. under 0.3, 0.5, and 0.7 MAD in clay loam soil were 445.15, 388.58 and 381.41 mm, and in sandy soil were 353.02, 317.59 and 290.54 mm, respectively. Also, the Kc coefficient of <em>Melia azedarach </em>L. during the growing period in clay loam soil under 0.3, 0.5, and 0.7 MAD were determined to be 0.34, 0.3, and 0.28 and in sandy loam soils were 0.27, 0.24, and 0.22, respectively.The growing population, the need to develop urban green space, water resources scarcity and the competition between different sectors of water consumption have necessitated to determine the accurate crop water requirement of different species in green spaces. In this study, a factorial experiment with two factors (soil texture and drought stress) was conducted to determine evapotranspiration (ETc) and crop coefficient (Kc) of <em>Melia azedarach L</em>. using microlysimeters based on a randomized complete block design (RCBD) with 10 replications. This study was performed in the climatic conditions of Karaj during 2019-2020. Soil texture consisted of clay loam and sandy loam and drought stress levels consisted of 0.3, 0.5, and 0.7 of management allowed depletion (MAD). The results showed that the 10-day ETc under 0.3, 0.5, and 0.7 MAD were 15.35, 13.81 and 12.63 mm in clay loam and they were 19.35, 16.9 and 16.58 mm in sandy loam soil, respectively. In both clay loam and sandy loam soils, the ETc decreased as drought stress increased. During the growing season, total net water requirement of <em>Melia azedarach </em>L. under 0.3, 0.5, and 0.7 MAD in clay loam soil were 445.15, 388.58 and 381.41 mm, and in sandy soil were 353.02, 317.59 and 290.54 mm, respectively. Also, the Kc coefficient of <em>Melia azedarach </em>L. during the growing period in clay loam soil under 0.3, 0.5, and 0.7 MAD were determined to be 0.34, 0.3, and 0.28 and in sandy loam soils were 0.27, 0.24, and 0.22, respectively.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219The Effect of Crop Residue on Organic Carbon and Fertility of the Soil in Wheat-Corn RotationThe Effect of Crop Residue on Organic Carbon and Fertility of the Soil in Wheat-Corn Rotation320732197843610.22059/ijswr.2020.305809.668666FAMoradMirzaeiDepartment of Soil Science and Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran.ManouchehrGorji AnariDepartment of Soil Science and Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, IranEhsanRazavy-ToosiDepartment of Plant, Soil and Microbial Sciences, Michigan State University, Michigan, USAHosseinAsadiDepartment of Soil Science and Engineering, Tehran University, Karaj, Iran0000-0003-2333-4938EbrahimMoghisehNuclear Agriculture School, Nuclear Science and Technology Research Institute, Karaj, IranSeyed MortezaZamirFaculty of Chemical Engineering, Tarbiat Modares University, Tehran, IranJournal Article20200710Addition of plant residues is an effective strategy for increasing soil nutrients, improving their use efficiency, providing better conditions for root growth and sustainable crop production. A field experiment was conducted to assess the effects of incorporation of varying rates of crop residue on the soil organic carbon and nutrients status at 0-10, and 10-20 cm soil depth, in a wheat-corn rotation under conventional tillage system. The field experiment was performed as a factorial and in the form of completely randomized block design with four replications in the farm of agricultural and natural resources college of University of Tehran for two growing years. The treatments included incorporation of five levels of crop residues (100, 75, 50, 25 and 0%) which were added to the soil in two steps, following wheat and corn rotation. The results of this study indicated a significant effect of crop residues on the measured properties. Among the crop residues treatments, the 100% level showed the greatest increase of organic carbon (38.4%), available phosphorus (34%) and potassium (47.6%), as well as iron (27%), manganese (30.3%), copper (39.5%) and zinc (62%), as compared to 0% residue treatment. The 25% residue treatment showed the lowest value for the studied properties, compared to other residues treatments. Available phosphorus, iron and zinc were significantly affected by depth and their values decreased with increasing depth from 0-10 to 10-20 cm.Addition of plant residues is an effective strategy for increasing soil nutrients, improving their use efficiency, providing better conditions for root growth and sustainable crop production. A field experiment was conducted to assess the effects of incorporation of varying rates of crop residue on the soil organic carbon and nutrients status at 0-10, and 10-20 cm soil depth, in a wheat-corn rotation under conventional tillage system. The field experiment was performed as a factorial and in the form of completely randomized block design with four replications in the farm of agricultural and natural resources college of University of Tehran for two growing years. The treatments included incorporation of five levels of crop residues (100, 75, 50, 25 and 0%) which were added to the soil in two steps, following wheat and corn rotation. The results of this study indicated a significant effect of crop residues on the measured properties. Among the crop residues treatments, the 100% level showed the greatest increase of organic carbon (38.4%), available phosphorus (34%) and potassium (47.6%), as well as iron (27%), manganese (30.3%), copper (39.5%) and zinc (62%), as compared to 0% residue treatment. The 25% residue treatment showed the lowest value for the studied properties, compared to other residues treatments. Available phosphorus, iron and zinc were significantly affected by depth and their values decreased with increasing depth from 0-10 to 10-20 cm.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219The Effect of Temperature on the Settlement Behavior of Fine-Grained Soil Stabilized with CementThe Effect of Temperature on the Settlement Behavior of Fine-Grained Soil Stabilized with Cement322132357827610.22059/ijswr.2020.309946.668736FASeyedeh ShokoofehYousefiDepatrment of Civil Engineering, Faculty of Engineering, Golestan University, Gorgan, Iran.AlirezaTabarsaDepatrment of Civil Engineering, Faculty of Engineering, Golestan University, Gorgan, Iran.YounesBagheriFaculty of Engineering, Mirdamad Institute of Higher Education, Gorgan, Iran.Journal Article20200913In this research, heat effects on settlement characteristics of cement-stabilized fine-grained soil have been considered in laboratory using standard compaction and thermal consolidation tests. Thermal consolidation tests were conducted by designing a consolidation cell instrument equipped with thermocouple and thermometer on different cement-stabilized samples at various curing times. Samples were tested at temperatures of 30, 45 and 60 <sup>0C</sup>; cement contents of 4, 6 and 8 percent; and curing times of 7 and 28 days. According to the results, consolidation will be improved in cement-stabilized soils if heat is used. Moreover, settlement time decreases and consolidation speed increases. The results also show that increasing temperature from 20 <sup>0C</sup> (room temperature) to 60 <sup>0C</sup> may increase soil settlement. This is while increasing cement content from 4 to 8 percent leads to decrease soil settlement. Besides, increasing curing time from 7 to 28 days under specific temperature and cement content, causes a significant decrease in soil compression index. Among different samples investigated in this research, the minimum compression index was observed in 28 day-cured specimens reinforced with 8 percent cement at temperature of 30 <sup>0C</sup> while the maximum swelling index was observed in natural soil. The findings also revealed that in 7 day-cured specimens under temperature of 30 <sup>0C</sup> with increasing cement content from 4 to 8 percent, compression and swelling index values have been decreased to 14 and 30 percent, respectively.In this research, heat effects on settlement characteristics of cement-stabilized fine-grained soil have been considered in laboratory using standard compaction and thermal consolidation tests. Thermal consolidation tests were conducted by designing a consolidation cell instrument equipped with thermocouple and thermometer on different cement-stabilized samples at various curing times. Samples were tested at temperatures of 30, 45 and 60 <sup>0C</sup>; cement contents of 4, 6 and 8 percent; and curing times of 7 and 28 days. According to the results, consolidation will be improved in cement-stabilized soils if heat is used. Moreover, settlement time decreases and consolidation speed increases. The results also show that increasing temperature from 20 <sup>0C</sup> (room temperature) to 60 <sup>0C</sup> may increase soil settlement. This is while increasing cement content from 4 to 8 percent leads to decrease soil settlement. Besides, increasing curing time from 7 to 28 days under specific temperature and cement content, causes a significant decrease in soil compression index. Among different samples investigated in this research, the minimum compression index was observed in 28 day-cured specimens reinforced with 8 percent cement at temperature of 30 <sup>0C</sup> while the maximum swelling index was observed in natural soil. The findings also revealed that in 7 day-cured specimens under temperature of 30 <sup>0C</sup> with increasing cement content from 4 to 8 percent, compression and swelling index values have been decreased to 14 and 30 percent, respectively.University of TehranIranian Journal of Soil and Water Research2008-479X511220210219Evaluation of Iran Meteorological Measurement and Monitoring NetworkEvaluation of Iran Meteorological Measurement and Monitoring Network323732527854610.22059/ijswr.2020.306713.668678FAHamidKardan MoghaddamAssistant Professor, Department of Water resources research, Water research institute, Ministry of Energy, Tehran, Iran0000-0003-4018-4388HosseinDehbanResearch assistant, Irrigation and Reclamation Engineering Department, College of Agriculture & Natural Resources, University of Tehran, Karaj, IranAlirezaKavousiAssistant Professor, Department of Water resources research, Water research institute, Ministry of Energy, Tehran, IranRezaRoozbahaniAssistant Professor, Department of Water resources research, Water research institute, Ministry of Energy, Tehran, IranMasoudBahreinimotlaghAssistant Professor, Department of Water resources research, Water research institute, Ministry of Energy, Tehran, Iran0000-0001-9009-663XMohammad JavadZareianAssistant Professor, Department of Water resources research, Water research institute, Ministry of Energy, Tehran, IranJournal Article20200721Proper utilization of available water resources and implementation of development plans requires an accurate database and updating of statistical and meteorological information. The process of measuring meteorological data until it is recorded in a database is an accurate, sensitive and time-consuming process. This study examines the country's meteorological network, which is managed under the supervision of the Ministry of Energy, and the pathology of the current state of meteorological measurements. Accordingly, network evaluation was performed in three major sections: network status evaluation in terms of statistics and field visits and evaluation of the measurement trustee. The survey of measurement system administrators varies around the world, and the focus of measurement varies from ministry to ministry, depending on the macro goals of water and water productivity in each country. A study of the statistics of the country's measurement network showed that one of the most important problems is the lack of stations in the highlands and the lack of a long-term statistical period. Although the construction of the stations is more than half a century old, proper management over time has not been able to observe a proper network. Field evaluation of meteorological stations in the country also showed that the lack of attention to the necessary equipment and infrastructure, the cost of the measurement process, lack of culture regarding the need for measurement, managers' inattention to the measurement process and etc. have been caused that the quality and quantity of measurements are affected. Establishing a proper monitoring network, although it has high initial costs, but the return on investment is necessary and important due to the necessity of statistics and information to implement any development plan.Proper utilization of available water resources and implementation of development plans requires an accurate database and updating of statistical and meteorological information. The process of measuring meteorological data until it is recorded in a database is an accurate, sensitive and time-consuming process. This study examines the country's meteorological network, which is managed under the supervision of the Ministry of Energy, and the pathology of the current state of meteorological measurements. Accordingly, network evaluation was performed in three major sections: network status evaluation in terms of statistics and field visits and evaluation of the measurement trustee. The survey of measurement system administrators varies around the world, and the focus of measurement varies from ministry to ministry, depending on the macro goals of water and water productivity in each country. A study of the statistics of the country's measurement network showed that one of the most important problems is the lack of stations in the highlands and the lack of a long-term statistical period. Although the construction of the stations is more than half a century old, proper management over time has not been able to observe a proper network. Field evaluation of meteorological stations in the country also showed that the lack of attention to the necessary equipment and infrastructure, the cost of the measurement process, lack of culture regarding the need for measurement, managers' inattention to the measurement process and etc. have been caused that the quality and quantity of measurements are affected. Establishing a proper monitoring network, although it has high initial costs, but the return on investment is necessary and important due to the necessity of statistics and information to implement any development plan.