POLYACRYLAMIDE APPLICATION IN IRRIGATION WATER OT INCREASE INFILTRATION

Abstract

Polyacrylamide was tested on furrow-irrigated cotton to assess its ability to improve infiltration on a Holtville silty clay loam (50% clay fraction consisting of 45% montmorillonite). Application was more effective as dilute solution in irrigation water than as dry powder on the soil surface. Solution concentrations of 25, 50, and 150 mg L-1 (6.6, 13.3, and 32.2 kg ha-1) were tested; the highest amount increased the infiltration rate of subsequent irrigations by 30 to 57% during the first 4 h. Final infiltration rate (after 12 h) and total water infiltrated were not increased by the polyacrylamide application, indicating that surface-sealing is not the limiting factor to permeability of soils with a high fraction of swelling clay.