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چكيده انگليسي :

73 Effect of Different Levels of Leaching Using Treated Wastewater on Soil Salt Balance Mohammad Ali Arab ma arab@ag iut ac ir Date of Submission January 11 2015 Department of Water Engineering College of Agriculture Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Behrouz Mostafazadeh Fard behrouz@cc iut ac irAbstractIn arid and semi arid regions wastewater treatment and reuse have become an important element in waterresources planning Some researchers believe that the use of treated wastewater for agriculture is anappropriate method because plant nutrients will be returned back to the soil and the environmentalpollution and pollution to the water resources will be reduced The use of treated wastewater for irrigationrequires that factors such as salinity to be considered The soil salinity is an important factor whichreduces crop production and also decreases the area under cultivations One of the problems of irrigationin arid and semi arid regions is the accumulation of salt in soil profile Due to limitation of availablewater for agriculture the use of low quality water for irrigation is increasing One of the effectivemethods to reduce soil salinity is leaching and leaching management Few studies are available about theleaching of soils irrigated with wastewater Therefore it is necessary to study the leaching requirementsof these conditions In this study the effect of two irrigation water treatments of well water andwastewater with three salinity levels of 1 3 5 and 6 dS m and three leaching levels of 10 20 and 30 onchemical characteristics of soil and drain water were studied for a sandy loam soil using experimental soilcolumns The experiments were conducted at the greenhouse of College of Agriculture IsfahanUniversity of Technology using factorial design with three replications The electrical conductivity andcations Na Ca2 and Mg2 of drain water and soil were analyzed for both irrigation water treatments atthe beginning middle and end of the experiments At salinity levels of 1 and 3 5 dS m there were nosignificant differences of electrical conductivity of drain water between two irrigation water treatmentsfor the beginning middle and end of the experiments At salinity level of 6 dS m and leaching levels of10 20 and 30 toward the end of experiment the difference between electrical conductivity of drainwater of two irrigation water treatments became significant At the end of the experiment soil sampleswere taken from soil depths of 0 15 15 30 and 30 45 cm and their chemical characteristics weredetermined At salinity levels of 1 and 3 5 dS m and for all leaching levels there were no significantdifferences between electrical conductivity of soil of two irrigation water treatments At salinity level of 6dS m at the leaching levels of 10 and 20 the differences between electrical conductivity of soils of twoirrigation water treatments were significant but at the leaching levels of 30 the difference was notsignificant The use of wastewater for irrigation requires proper management in order to prevent soil saltaccumulation Keywords Wastewater Saline water Leaching Salt balance Electrical conductivity

عرب، محمدعلي

اثر سطوح مختلف آبشويي با پساب بر بيلان املاح خاك

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