Missing the boat: Midwest farm drainage and Gulf of Mexico hypoxia

Research addressing Gulf hypoxia has failed to account for agricultural drainage, the major pathway of nitrate loads in Upper Midwest states. Focusing on two Minnesota watersheds, simulation results were combined with a constrained-optimization model to evaluate the cost-effectiveness of nitrogen-abatement policies, with explicit focus on drainage. Results indicate that drained land dominates in nitrogsen abatement, and has substantially lower abatement costs relative to nondrained land. However, policies that remove drainage were not cost-effective. Further, it was found that nutrient management, a policy strongly recommended by prior research, is relatively cost-ineffective as a means of abatement on non-drained land.