Reducing Nitrogen Loss in Subsurface Tile Drainage Water with Managed Drainage and Polymer-Coated Urea in a River Bottom Soil

Poorly-drained, river bottom soils can be high corn (Zea mays L.) yielding environments, but sa-turated soil conditions often reduce corn yields. Wabash soils located in river bottoms in North-east Missouri have not been traditionally tile drained due to high clay content which requires narrow tile drain spacings. Increased land prices in the region have increased interest in tile draining poorly-drained bottom land soils to increase corn yields which could have a deleterious effect on water quality. The objectives of the three-year study were to determine whether use of managed subsurface drainage (MD) in combination with a controlled release N fertilizer could reduce the annual amount of 3 −NO-N loss through tile drainage water compared to free subsur-face drainage (FD) with a non-coated urea application. Annual 3 −NO-N loss through tile drainage water with FD ranged from 28.3 to 90.1 kg·N·ha−1. Nitrogen fertilizer source did not affect 3 −NO-N loss through tile drainage water, which was likely due to limited corn uptake over the three-yea