Risk versus Economic Return in Managing Groundwater Nitrate Contamination

Abstract

A nitrate transport model was developed to project the impact of a substantial buildup of nitrate in the groundwater in the eastern Sandhills region of Nebraska. Predicted nitrate levels were evaluated using a Multi-Criteria Decision Making technique. Two criteria were used to determine optimum farm management practices: economic return to the irrigators and risk to domestic water users. The optimum farm management practice consisted of an above average irrigation rate and a below average nitrogen fertilizer rate. The low fertilization rate had one of the lowest risks of excessive ground water nitrate levels, while the high irrigation rate maximized the economic return. Therefore, this practice was optimal because it was the best compromise between minimum risk and maximum economic return. The risk of excessive groundwater nitrate for the optimum practice was 51 percent and for the other seven practices simulated ranged up to 54 percent.