Effect of Managed Subsurface Drainage and Polymer-Coated Urea On Nutrient Loss From a Silty Clay Soil in Corn Production.

Low crop production on poorly drained soils is typically due to saturated soil conditions which can impede time sensitive management, inhibit plant growth, and significantly increase -N loss. Over 850 thousand hectacres of farmland in Missouri could benefit from the installation of subsurface drainage systems. However, environmentally detrimental amounts of N can enter surface water sources, as a result of subsurface drainage. A four year subsurface drainage study was initiated on an alluvial soil (Wabash – silty clay) in corn production starting in June, 2010.  The objective of this research is to determine if a slow release N fertilizer (polymer-coated urea) and managed subsurface drainage can significantly reduce nitrate-N loss in subsurface drainage water compared to non-coated urea and conventional subsurface drainage. Nitrate-N loss data from 2010-12 is currently being analyzed at this time.