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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVING SOIL AND NUTRIENT MANAGEMENT SYSTEMS FOR SUSTAINED PRODUCTIVITY AND ENVIRONMENTAL QUALITY

Location: Soil Plant Nutrient Research (SPNR)

Title: Nitrogen Fertilization Effects on Nitrous Oxide Emissions from Irrigated Cropping Systems

Authors
item Halvorson, Ardell
item Del Grosso, Stephen
item Reule, Curtis

Submitted to: Proceedings of Great Plains Soil Fertility Conference
Publication Type: Proceedings
Publication Acceptance Date: January 12, 2008
Publication Date: March 4, 2008
Citation: Halvorson, A.D., Del Grosso, S.J., Reule, C.A. Nitrogen fertilization effects on nitrous oxide emissions from irrigated cropping systems. Proc. of 2008 Great Plains Soil Fertility Conference. Denver, CO March 4-5, 2008. Kansas State University, Manhattan and Potash and Phosphate Institute, Brookings, SD. 12:28-22.

Interpretive Summary: The effects of N fertilization and irrigated crop management practices on nitrous oxide (N2O) emissions from the soil were evaluated during the 2006 and 2007 growing seasons. Emissions were monitored from several irrigated cropping systems receiving N fertilizer rates ranging from 0 to 246 kg N/ha. Cropping systems included: conventional-till (CT) continuous corn (CC) (CT-CC); no-till (NT) CC (NT-CC); NT corn-dry bean (NT-CDb); and NT corn-barley (NT-CB). All plots were in corn in 2006, with a polymer-coated urea, ESN®1, being applied at half the N rate at corn emergence and half as dry urea in mid-June followed by irrigation. In 2007, ESN® and urea were applied at the full N rate at corn emergence to separate plots in the CT-CC and NT-CC rotations and urea and SuperU®1 were applied to separate plots after barley emergence in the NT-CB rotation and at dry bean emergence in the NT-CDb plots. N2O fluxes were measured during the growing season using static, vented chambers, one to three times per week, and a gas chromatograph analyzer. Linear increases in N2O emissions were observed with increasing N-fertilizer rate in 2006. Growing season N2O emissions in 2006 were greater from the NT-CDb system than from the other cropping systems. In 2006 and 2007, N2O emissions tended to be greater from the CT-CC system than from the NT-CC system. Application of ESN® and SuperU® fertilizers resulted in reduced N2O emissions in the NT systems. Spikes in N2O emissions following N fertilizer application were greater with urea than with the ESN® or SuperU® fertilizers. The ESN® and SuperU® fertilizer N products showed potential for reducing N2O emissions from irrigated cropping systems in 2007. These first year results indicate that N sources need to be evaluated further to determine their value in reducing N2O emissions in cropping systems.

Technical Abstract: We evaluated the effects of N fertilization and irrigated crop management practices on nitrous oxide (N2O) emissions. Emissions were monitored from several irrigated cropping systems receiving N fertilizer rates (0, 67, 134, and 246 kg N/ha) during the 2006 growing season and N rates of 0 and 246 kg N/ha on corn plots, 0 and 156 kg N/ha on barley plots, and 0 and 56 kg N/ha on the dry bean plots during the 2007 growing seasons. Cropping systems included: conventional-till (CT) continuous corn (CC) (CT-CC); no-till (NT) CC (NT-CC); NT corn-dry bean (NT-CDb); and NT corn-barley (NT-CB). All plots were in corn in 2006, with a polymer-coated urea, ESN®1, being applied at half the N rate at corn emergence and half as dry urea in mid-June followed by irrigation, both banded on the soil surface in the corn row. In 2007, ESN® and urea were applied at the full N rate at corn emergence to separate plots in the CT-CC and NT-CC rotations and urea and SuperU®1 were applied to separate plots after barley emergence in the NT-CB rotation and at dry bean emergence in the NT-CDb plots. N2O fluxes were measured during the growing season using static, vented chambers, one to three times per week, and a gas chromatograph analyzer. Linear increases in N2O emissions were observed with increasing N-fertilizer rate in 2006. Growing season N2O emissions in 2006 were greater from the NT-CDb system than from the other cropping systems. In 2006 and 2007, N2O emissions tended to be greater from the CT-CC system than from the NT-CC system. Application of ESN® and SuperU® fertilizers resulted in reduced N2O emissions in the NT systems. Spikes in N2O emissions following N fertilizer application were greater with urea than with the ESN® or SuperU® fertilizers. The ESN® and SuperU® fertilizer N products showed potential for reducing N2O emissions from irrigated cropping systems in 2007. These first year results indicate that N sources need to be evaluated further to determine their value in reducing N2O emissions in cropping systems.

Last Modified: 7/31/2014