Nitrogen Management Influences on N Losses to Tile and Surface Water

Nitrogen (N) is a naturally occurring element that is essential to plant growth and crop production. Agriculture has been identified frequently as a major contributor of nitrate-nitrogen to surface water throughout the developed world. Omernik (1977) reported that total N concentrations were nearly nine times greater downstream from agricultural lands than downstream from forested areas with the highest concentrations being found in the Corn Belt States of the Upper Mississippi Basin. Nitrate-N is continually supplied to streams and rivers through mineralization of soil organic matter, particularly where tile drainage has exposed formerly wet soils to oxidation and through the application of fertilizer and animal manures to crop land