Management practices for erosion and sediment control in irrigated agriculture

Irrigation erosion and subsequent sediment losses to rivers and streams continue to be serious problems confronting irrigated agriculture. The seriousness of these problems depends upon user concerns which in turn depend upon geographic area and populations. Erosion problems are less severe in California than in Idaho, but the concern for controlling water quality can be greater in parts of California because of subsequent water uses. Basin irrigating rice can reduce suspended sediment loads in water because the basins serve as sediment retention basins. Furrow erosion causes significant suspended sediment loads in return flows in California, but the problem is much more severe in Idaho. Topsoil redistribution by furrow erosion and sedimentation has reduced potential crop yields by approximately 25%. Several sediment loss control practices have been developed and evaluated, and are effective, but costs deter their application. Research is presently directed toward controlling erosion along irrigation furrows. Methods to increase soil cohesion and utilize residues in minimum tillage and no-till systems have high potential for controlling erosion and sediment loss during the next decade