Improving water quality of return flows in furrow-irrigated systems using polymer-amended inflows

Furrow irrigation is an inherently erosive process. When irrigating erosive soils or supra-optimal slopes soil loss can greatly exceed T-values (Carter,1990). Soil sediment lost in return flows and nutrients and other chemicals adsorbed on the sediment are major contributors to non-point pollution of surface water (Brown, et al., 1981). Although numerous practices have been developed to combat erosion from furrow irrigated systems their adoption has been hampered by cost and inconvenience (Sojka, et al., 1992). The Kimberly ARS group has recently conducted a series of field studies verifying the efficacy of minute polymer additions for halting erosion and stabilizing infiltration of irrigated furrows. Beyond its high efficacy, this approach is attractive because of its simplicity and low cost (Lentz, et al., 1992). The technology requires only the use of simple fluid injection devices to treat irrigation water, at a material cost below $3.00 per hectare per irrigation.