Analyzing the soil texture effect on promoting water holding capacity by polyacrylamide

Abstract

Polyacrylamide (PAM) has been widely used to improve soil water holding capacity and control infiltration rate of the soils. However, limited studies have been conducted on the interactions between soil water holding capacity and PAM rates in different soil textures. This study targeted to analyze the relations between soil texture and water holding capacity as a response of increasing PAM applications rate. PAM rates of 0.03, 0.1, 0.13, 0.16, 0.23, 0.33 and 0.67% by weight were applied to clay loam, clay and sandy loam soils. Water holding capacity (q) at field capacity (q 0.01 MPa for sandy loam and q0.033MPa for clay loam and clay) and wilting point (q1.50 MPa) were measured with a pressure plate apparatus. The values of water holding capacity were regressed as a function of PAM rate, and the slope and intercepts of regression lines for clay loam, clay and sandy loam soils were compared to decide the homogeneity of these functions. Increasing PAM rate significantly increased the water holding capacity in all three soils (P<0.05). The regression lines obtained for sandy loam, clay loam, and clay were all significantly different from one to another, revealing that soil texture has a significant effect on the function of PAM in promoting water holding capacity in these soils. Therefore, we concluded that soil texture should be considered in optimizing the results from PAM applications.