Fertilizer Management Practices to Increase Nitrogen Use Efficiency of Corn Under High Clay Soil.

Application of Nitrogen (N) fertilizers in crop production agriculture has been identified as a major producer of Nitrous oxide (N₂O), a potent greenhouse gas. Installing subsurface drainage system under crop production may influence the soil N₂O emissions through altering soil moisture and temperature regimes. The use of improved N management practices such as slow release or inhibitor treated N fertilizers and split N application in corn (Zea mays L.) can potentially reduce N₂O emissions by improving the coordination of the N availability and plant uptake. A two year field experiment will be initiated in 2012, at a NDSU experimental site near Fargo, North Dakota, to compare the N₂O emissions from corn fields fertilized with urea, urea with Instinct (nitrification inhibitor), ESN (polymer coated urea), and UAN (split N application) with Agrotain (urease inhibitor) under tile drained and un-drained conditions with four replications. All the fertilizers are applied at the rate of 200 lb N ha^-1 and a control plot with 0 N is also included. Nitrous oxide fluxes from the corn plots are measured biweekly during each growing season by sampling headspace air from the semi-permanent vented static PVC chamber and analyzing on gas chromatograph, equipped with electron capture detector. Our work will identify fertilizer N management strategies to minimize N₂O emissions from corn fields grown in high clay soils under subsurface drainage condition.