U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
2011
Citation
FLUID FERTILIZER FOUNDATION, February 20-22, 2011, Volume 28
Abstract
We evaluated the effects of nitrogen (N) source on nitrous oxide (N2O) emissions from a clay loam soil that was in strip-tilled (ST), irrigated continuous corn production in 2010 near Fort Collins, CO. Emissions were monitored from six different inorganic N fertilizer sources (urea, ESN1, SuperU, UAN, UAN+AgrotainPlus, UAN+Nfusion). Each N source was applied at a rate of 202 kg N/ha, surface band applied near the corn row and watered into the soil the day after application including a subsurface band application of ESN (ESNssb). A check treatment (no N applied since 2000) located in separate plots and a blank treatment (no N applied) located within the N source plots were included. All treatments except the check were located in plots ST in 2009 that had received 202 kg N/ha of ESN. Nitrous oxide fluxes were measured during the growing season using static, vented chambers for gas sample collection, one to three times per week, and analyzed with a gas chromatograph. With the exception of ESNssb, all N sources had significantly lower growing season N2O emissions than dry granular urea. Cumulative increases in daily N2O fluxes were more rapid for urea and UAN than the other N sources following N fertilizer application. The enhanced efficiency fertilizers (polymer-coated, stabilized, and slow release) sources showed potential for reducing N2O emissions during the 2010 growing season. Corn grain yields in 2010 were not significantly different among N sources, but greater than the blank or check treatments with no N applied. These results indicate that N source selection can be of value in reducing N2O emissions in irrigated cropping systems under strip-till in the Central Great Plains.