Much of the U.S. Corn Belt is characterized by relative flat, poorly-drained areas which with extensive subsurface drainage, have become some of the most valuable and productive agricultural land in the world. However, this is not without consequences. Nitrate-N loss from these systems is of particular concern due to its potential adverse impacts on both public health and ecosystem function. In addition to the potential local impacts on receiving waters in the Corn Belt, nitrogen loads from the region are suspected as a primary contributor to hypoxia in the Gulf of Mexico. For nearly 30 years Iowa State University has been studying the impacts of nitrogen and land management practices on drainage water quality at a variety of sites throughout the state.