Nitrogen (N) fertilizer applications are necessary for high yield corn production. However, water quality impairment related to N loss from corn and soybean fields continues to be a concern in Iowa, including meeting the USEPA nitrate (NO3-–N) drinking water standard, meeting proposed surface water quality nutrient criteria, and reducing N export to the Gulf of Mexico. Therefore, in-field production practices are needed to aid in reduction of NO3- leaching and movement to water systems.