Nitrogen source effects on nitrous oxide emissions from irrigated no-till corn.
Nitrogen fertilization is essential for optimizing crop yields; however, it may potentially increase nitrous oxide (N2O) emissions. The study objective was to assess the ability of commercially available enhanced-efficiency N fertilizers to reduce N2O emissions following their application in comparison with conventional dry granular urea and liquid urea-ammonium nitrate (UAN) fertilizers in an irrigated no-till (NT) corn (Zea mays L.) production system. Four enhanced-efficiency fertilizers were evaluated: two polymer-coated urea products (ESN and Duration III) and two fertilizers containing nitrification and urease inhibitors (SuperU and UAN+AgrotainPlus). Nitrous oxide fluxes were measured during two growing seasons using static, vented chambers and a gas chromatograph analyzer. Enhanced-efficiency fertilizers significantly reduced growing-season N2O-N emissions in comparison with urea, including UAN. SuperU and UAN+AgrotainPlus had significantly lower N2O-N emissions than UAN. Compared with urea, SuperU reduced N2O-N emissions 48%, ESN 34%, Duration III 31%, UAN 27%, and UAN+AgrotainPlus 53% averaged over 2 yr. Compared with UAN, UAN+AgrotainPlus reduced N2O emissions 35% and SuperU 29% averaged over 2 yr. The N2O-N loss as a percentage of N applied was 0.3% for urea, with all other N sources having significantly lower losses. Grain production was not reduced by the use of alternative N sources. This work shows that enhanced-efficiency N fertilizers can potentially reduce N2O-N emissions without affecting yields from irrigated NT corn systems in the semiarid central Great Plains.
USDA-ARS, 2150 Centre Ave., Bldg. D, Ste. 100, Fort Collins, CO 80526, USA. ardell.halvorson@ars.usda.gov
Ardell D
AD
Halvorson
Stephen J
SJ
Del Grosso
Alluvione
A
Francesco
D057914:Agricultural Irrigation; D002245:Carbon Dioxide / Q000032:analysis; D002980:Climate; D018556:Crops, Agricultural / Q000737:chemistry*; D008697:Methane / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis*; D014867:Water; D003313:Zea mays / Q000737:chemistry*
D014867:Water; D002245:Carbon Dioxide; D009609:Nitrous Oxide; D008697:Methane