Nitrogen Source Effects on Soil Nitrous Oxide Emissions from Strip-Till Corn
- Ardell D. Halvorson *a,
- Stephen J. Del Grossoa and
- Claudia Pozzi Jantaliab
- a USDA–ARS, 2150 Centre Ave, Bldg. D, Ste. 100, Fort Collins, CO 80526
b Embrapa Agrobiology, Road BR Km 7, Seropedica, Rio de Janeiro 23890-000, Brazil. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by USDA. USDA is an equal opportunity provider and employer. Contribution from USDA–ARS, Fort Collins, CO
Nitrogen (N) application to crops generally results in increased nitrous oxide (N2O) emissions. Commercially available, enhanced-efficiency N fertilizers were evaluated for their potential to reduce N2O emissions from a clay loam soil compared with conventionally used granular urea and urea-ammonium nitrate (UAN) fertilizers in an irrigated strip-till (ST) corn (Zea mays L.) production system. Enhanced-efficiency N fertilizers evaluated were a controlled-release, polymer-coated urea (ESN), stabilized urea, and UAN products containing nitrification and urease inhibitors (SuperU and UAN+AgrotainPlus), and UAN containing a slow-release N source (Nfusion). Each N source was surface-band applied (202 kg N ha−1) at corn emergence and watered into the soil the next day. A subsurface-band ESN treatment was included. Nitrous oxide fluxes were measured during two growing seasons using static, vented chambers and a gas chromatograph analyzer. All N sources had significantly lower growing season N2O emissions than granular urea, with UAN+AgrotainPlus and UAN+Nfusion having lower emissions than UAN. Similar trends were observed when expressing N2O emissions on a grain yield and N uptake basis. Loss of N2O–N per kilogram of N applied was <0.8% for all N sources. Corn grain yields were not different among N sources but greater than treatments with no N applied. Selection of N fertilizer source can be a mitigation practice for reducing N2O emissions in strip-till, irrigated corn in semiarid areas.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2011. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.