Basing nitrogen applications on a realistic crop yield goal can significantly reduce the amount of nitrogen lost to tile-lines and streams. We don't know the precise effect of management practices that reduce nitrate leaching, but we do know that winter cover crops, controlled application rate, split application with proper timing of applications, and the use of nitrification inhibitors can help to reduce nitrate flow in tile drains. Thus, even a strong commitment to improving nitrogen management will not completely eliminate nitrogen losses from agriculture, because many variables affect nitrogen use and losses in the field. What We're Doing Purdue University is evaluating movement of nutrients through soil into subsurface drains at two sites. Monitoring at both sites shows nitrate present in all subsurface drainage water, especially from Novem-ber through May or June.
Research includes studies on timing of nitrogen applications and split applications approaches.
Current efforts focus on the use of wetlands and other best management practices to manage nutrients.