تاثير شوري آب آبياري و آبشويي خاك بر عملكرد سويا

چكيده انگليسي :

Effect of irrigation water salinity and soil leaching on soybean yield Amir Hossein Dadgostar Darani dadgostar amir@yahoomail com Date of submission on June Department of Water Engineering College of Agriculture Isfahan University of Technology Isfahan Iran Degree M Sc Language Farsi Supervisor Behrouz Mostafazadeh Fard behrouz@cc iut ac ir Abstract Salinity of soil and water resources is one of the most important problems which reduce agricultural production and gradually decrease the area under cultivations Salt accumulation in the soil profile is one the major problems in irrigated lands in arid and semi arid regions Irrigation water even with the best quality carries some soluble salts to the soil and increase the soil salinity in most of the cases Considering the scarcity of water resources for agriculture irrigation with poor quality waters is being increasing One of the effective methods of reducing the salinity hazard is the application of leaching and leaching management In this study the effect of three irrigation water qualities of and dS m and three leaching levels of and percent on yield and yield components of soybean and some chemical characteristics of soil and drainage water in a loam texture soil was investigated The soybean variety that was selected fot this study was Gorgan The study was carried out in a greenhouse at the College of Agriculture Isfahan University of Technology in completely randomized design as farctorial with four replications The results showed that as the salinity of irrigation water increases and leaching level decreases the soil salinity sodium adsorption ratio and exchangeable sodium percent increase and these increases are greater for soil depth of cm as compared to soil depth of cm The increase of irrigation water salinity and leaching level increase soil pH and soil pH was greater at the lower soil layer as compared to the top layer but the differences were not significant With increase of quality and quantity of leaching water the soybean grain yield plant elevation flowering duration riping duration weight of grains plant dry weight number of filled pods number of all pods seasonal evapo transpiration and harvest index increase but number of infetile pods decrease The study of Mass Hoffman equation showed that the parameter of a is equal to dS m and the parameter of b is equal to percent per dS m increase in soil salinity From comparison of the results of this study with the previous studies for soybean it can be concluded that as soil salinity levels increase Gorgan variety has less threshold decrement yield but has better tolerance to salinity The study of Stewart equation showed that the parameter of b in this equation is equal to As salinity of irrigation water increased the salinity of drainage water increased Application of leaching in the best and worst applied irrigation water qualities salinity of and dS m had the most and least leaching efficiency respectively The most saline drainage water and the most changes in salinities of drainage waters were belonged to the four first irrigations at the beginning of the season In the later irrigations the changes in salinity of drainage water decreased significantly and the changes became nearly consonant The changes in pH of drainage water were irregular and the changes were not significant and it increased during the irrigation season The reason of these irregular changes were changes in concentrations of carbonate and bicarbonate ions in the drainage water which these ions concentrations changes caused by the changes in temperature and air pressure of environment Keywords Salinity Leaching Soybean Harvest index PDF created with pdfFactory trial version www pdffactory com

دادگستر داراني، اميرحسين

تاثير شوري آب آبياري و آبشويي خاك بر عملكرد سويا

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