Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 25, 2008
Publication Date: N/A
Technical Abstract: The effect of several N sources on nitrous oxide (N2O) emissions from an irrigated, no-till (NT) continuous corn field was investigated. Emissions were monitored in plots receiving 246 kg N/ha during the 2007 growing season and 202 kg N/ha during the 2008 growing season. Nitrogen sources included dry granular urea, liquid urea-ammonium nitrate (UAN), two polymer-coated urea (PCU) sources, and urea and UAN treated with nitrification and urease inhibitors. The N was surface band applied in the corn row at emergence with 1.3 cm of irrigation water applied within 3 days of N application. Plot size was 2.7 x 4.6 m for each N source, with 3 replications in a randomized complete block design. N2O fluxes were measured during the growing season at two locations within each plot using static, vented chambers, one to three times per week, and a gas chromatograph analyzer. In 2007, N2O emissions were not significantly different between urea and UAN. The PCU fertilizers and urea and UAN fertilizers treated with nitrification and urease inhibitors showed significantly lower N2O emissions than dry granular urea in 2007. Only the urea and UAN sources treated with the nitrification inhibitors had significantly lower N2O emissions than UAN in 2007. Based on the 2007 results, these N sources need further evaluation to determine their effectiveness in reducing N2O emissions in irrigated cropping systems. The study was continued in 2008. [GRACEnet ublication].