Submitted to: Idaho Winter Commodity School Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 25, 1996
Publication Date: N/A
Interpretive Summary: Loss of the A horizon from Idaho soils reduces yield potential 20-50%. Soil loss in tailwater of over 20 tons per acre have been recorded for a single furrow irrigation. Erosion of soil and agricultural chemicals are major non-point pollution sources with high societal costs that are often hidden from direct economic analysis. Erosion also threatens sustainability of irrigated agriculture which is usually conducted on fragile arid soils. Because irrigated agriculture's efficiency is double that of rainfed agriculture, the loss of irrigated land doubly threatens natural environments which would have to be put into production to sustain production. Farmer's needs for conservation practices that prevent erosion from irrigated lands vary with each farming operation. This paper describes fourteen major categories of conservation practice, estimates their effectiveness, and lists of advantages and disadvantages of each practice. No single practice is promoted over another, and the philosophy of fail-safe conservation management is promoted.
Technical Abstract: Loss of the A horizon from Idaho soils will reduce yield potential of commonly grown irrigated crops 20-50%. Soil loss in tailwater of over 20 tons per acre have been recorded for a single furrow irrigation. Soil and agricultural chemicals in runoff are major non-point source of pollution in riparian environments and receiving waters. Societal costs of irrigation induced erosion are high but are often hidden from direct economic analysis. Erosion seriously threatens sustainability of irrigated agriculture. No single erosion management option is ideal for all situations, and it is desirable to use layers of conservation practices to protect the soil resources in a fail-safe strategy. The best erosion abatement practices are those that prevent soil from moving within or from the field. Some effective options include sediment retention basins, buried pipe erosion control systems, vegetative filter strips, twin row and close row planting, tailwater reuse, improved water management, furrow mulching, whey application, polyacrylamide application, EC and SAR control, conservation tillage, zone subsoiling, reservoir tillage, and low pressure and wide-area spray emitters for sprinklers.