Technologies to Minimize Water Quality Impacts of Irrigated Agriculture

Abstract

Irrigation transformed arid land in the Pacific Northwest into productive agricultural land. However, much of this land is prone to erosion during irrigation, which can cause problems on and off of the field. Management practices have been developed to control soil erosion on irrigated land and improve the quality of water returning to streams and rivers. Applying polyacrylamide (PAM) with irrigation water can reduce erosion from furrow irrigated fields more than 90%. Using PAM in combination with other practices, such as applying straw mulch in furrows and installing small sediment ponds on fields, can virtually eliminate sediment loss fromfields. Once soil runs off a field, it can be removed by settling in sediment ponds, although soluble nutrients remain in the water. Applying 20 mg/L alum to irrigation return flow water can remove about 50% of the soluble phosphorus that will not be removed as suspended sediment settlesin ponds. Using these management practices allows irrigation to continue with minimal impact on water quality.

Wastewater and Magnetized Wastewater Effects on Soil Erosion

“…Soil erosion due to irrigation, especially furrow irrigation, contributes to the nonpoint-source pollution of water (HAJEK et al, 1990) and is a serious threat to crop productivity in many regions (CARTER, 1993). It may damage water quality in rivers, lakes and streams (BJORNEBERG et al, 2005). A large amount of farm soil may be lost due to furrow erosion caused by runoff from furrows that transfers sediment (CARTER, 1993).…”