Controlling Sodic Soil Erosion by Electrolytes and Polyacrylamide Application

Abstract

The anionic polyacrylamide (PAM) is recently used to rehabilitate saline and sodic soils and control soil erosion. The research on the effectiveness of anionic PAM along with gypsum or lime application on soil erosion is rare and poorly documented. Therefore, an experiment was conducted to study the effects of anionic PAM with or without gypsum on the erosion of soils under saline/sodic conditions. For this purpose, a clay loam soil was prepared to achieve three levels of exchangeable sodium percentage (ESP) 0.5, 9.9, and 25.5 with an appropriate solution of salts. Soil samples were air-dried and packed in the trays. Powdered PAM, gypsum, or a mixture of both was applied to the salt-treated soils. Thereafter, the 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_w): 0.1, 2, 5, and 8 dS m⁻¹ were used for simulated rains during the study. PAM amendment substantially controlled the erosion of the soils. The ESP was directly associated with the soil erosion and runoff. Among the treatments, the resistance to soil erosion was developed in the order of PAM > gypsum ≈ saline water > PAM mixed with gypsum ≈ PAM mixed with saline water. The magnitude of runoff water was reduced both by gypsum and saline water, whereas it was enhanced by PAM application. The mixed addition of PAM with gypsum or salts exacerbated water erosion of soils.