Soil Nitrous Oxide Emission From a Maize Cropping System In the Southeastern U.S.

The majority of U.S. nitrous oxide (N₂O) emissions are a consequence of agricultural production. In 2010, 35.6 million hectares of maize were planted in the United States, making it the cropping system with the greatest potential for reducing greenhouse gas emissions. The purpose of this research was to explore the potential for reducing soil nitrous oxide emissions from maize being managed with split fertilizer application and improvements to plant health with application of a fungicide. A field site in Holly Springs, NC was planted with Zea mays ‘Dekalb’. The site was blocked to compensate for uneven drainage and half of the blocks were sprayed with fungicide at V6 and VT while the other half received no fungicide during spraying. Nitrogen was applied either at 125% the recommended rate during pre-plant or 25% at pre-plant and 100% at lay-by. Water status of the soil was monitored continuously.  Closed dynamic chambers and gas chromatography were used to capture and measure N₂O emissions throughout the growing season.