Nitrogen (N) management is an issue of great importance to Iowa agriculture. Corn and other crops are highly dependent on nitrogen and other fertilizers. Most of the nutrients that are applied to agricultural lands serve their intended purpose of increasing crop yields. However, substantial quantities flow from fields into waterways, where they degrade water quality in Iowa’s streams, lakes, and other water bodies. Some of that nutrient flow eventually finds its way into the Mississippi River and then the Gulf of Mexico, where it contributes to the formation of a large area of oxygen-depleted water known as a hypoxic zone. In short, the loss of nitrogen and other nutrients from agricultural activities leads to economic and environmental costs in Iowa and as far away as the Gulf of Mexico.