Irrigation Effects in Oklahoma and Texas

Groundwater contamination is a serious water quality problem since 50% of the population derives drinking water from groundwater sources. Severe water quality problems have resulted from deep percolation under irrigated areas, carrying high salt loads and increased nitrate concentrations to groundwater aquifers. This review looks at studies that have dealt with the effect of deep percolation from irrigation on groundwater quality. Recommendations are developed to minimize the undesirable effects of groundwater contamination by irrigated agriculture. Major among the conclusions is that improved and or more efficient irrigation and fertilizer management practices are required to minimize the adverse impact of irrigated agriculture on the quality of underlying groundwater. When water and nutrient application and use efficiencies are improved, deep percolation is decreased and less downward movement of pollutants occurs. Structural improvements in irrigation systems are a necessary aid to achieving the desired level of management.