Document Type : Research Paper
Authors
1 Assistant Professor, Department of Soil Science, Faculty of Agriculture, Shahrekord University, Shahrekord, Iran
2 M.Sc., Department of Soil Science, Faculty of Agriculture, Shahrekord University, Shahrekord, Iran
Abstract
In this study, the effects of Mianeh Zeolite and Taravat® A200 polymer on moisture content and available water content of a coarse-textured soil were investigated. Mianeh zeolite was applied at four levels (0%, 2%, 5%, and 8% on weight basis) and Taravat® A200 polymer was applied at 5 levels to the soil in a completely randomized experiment with 3 replications. Soil moisture content was determined at suctions of 0, 5, 7.5, 10, 33, 100, 500, and 1500 kPa using hanging water columns and pressure plate apparatus. The water retention curve model of Campbell (1974) was fitted to soil data. Results showed that both soil conditioners enhanced soil moisture content at measured soil suctions. The addition of more conditioner caused a larger response of soil. For example, application of 8% zeolite elevated the volumetric filed capacity from 11% to 13% and therefore increased available water content by 2% compared to the control. Also, addition of 0.2% A200 polymer increased the available water content by 6%. In addition, soil conditioners modified the shape of the moisture characteristic curve of the soil and influenced the parameters of water retention model in a manner exhibiting reduced water release rates plus the added benefit of an additive and/or a synergistic effect. For instance, simultaneous application of 5% Mianeh zeolite and 0.2% Taravat A200 polymer increased ye from 0.21 to 2.00 and decreased l from 7.37 to 5.40 and thereby increased the available water content by 7%. Simultaneous application of these amendments is possible and may reduce the needed water and/or increase irrigation intervals. Simultaneous application is also cheaper and probably will prevent plant root damage.
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