Evaluation of Powdered Polyacrylamide Application along with Source of Electrolytes in Controlling Sodic Soil Erosion

Abstract

The anionic polyacrylamide (PAM) is recently used to rehabilitate saline and sodic soils. It is also applied to control soil erosion ; however, few researches have tested the effectiveness of anionic PAM along with source of electrolytes application to control artificial sodic soil erosion. An experiment was conducted to study the effects of anionic PAM with and without gypsum on the erosion of sodic soils under saline rain water conditions. A clay loam soil was prepared to achieve three levels of exchangeable sodium percentage (ESP); 0.5, 9.9 and 25.5 with appropriate salts solutions. Soil samples were air-dried and packed in the trays. Powdered PAM, gypsum or a mixture of both were applied to the salt treated soils. Soils were subjected to simulated rainstorm of 40 mm h_1 by a fixed rainfall simulator. Saline waters with different levels of electrical conductivity (EC); 0.13, 2, 5, and 8dSm_1 were used for simulated rains during the study. It seems that the artificial soil showed fairly similar soil erosion characteristics as that reported on a natural sodic soil. It was found that the soil sodicity enhanced soil erosion under non-saline water. It seems that the effects of electrolyte source on soil erosion were affected by the soil initial electrical conductivity (ECe) rather than by the ESP level of soil. PAM amendment substantially increased the surface runoff while at the same time controlled the soil losses. A reduction in surface runoff was found by applying gypsum or saline water on the soil treated with PAM. However, it seems that the mixed addition of PAM with gypsum or salts enhanced detachments of soil particles by raindrop impact.