135-6 Tillage and N Source Effects On Nitrous Oxide Emissions From Soils.



Monday, October 17, 2011: 9:45 AM
Henry Gonzalez Convention Center, Room 218, Concourse Level

Craig F. Drury, W. Dan Reynolds, Xueming Yang, Tom W. Welacky, Neil B. McLaughlin, Wayne Calder and Cynthia A. Grant, Agriculture & Agri-Food Canada, Greenhouse & Processing Crops Research Centre, Harrow, ON, Canada
A three-year study was conducted to determine the effectiveness of varying the application times and N fertilizer source on corn grain yields and N2O losses from soil under conventional tillage (CT), zone tillage (ZT) or no-tillage (NT) in Southwestern Ontario.  On average, there was 2.80 kg N ha-1 lost from the CT treatments and these losses were reduced by 10.7% with NT and by 36.4% with ZT.  Applying N as a sidedress application reduced N2O losses by 37.9% compared to applying all of the fertilizer N as a pre-plant application.  In 2004, there were significant effects of urea source on N2O emissions with regular urea having 1.8 to 4.2 times more N2O evolved than coated urea when applied to CT treatments.  However, urea source did not significantly affect N2O emissions in either 2005 or 2006.  The 3-yr corn grain yields were on average, 12% greater with CT (9.38 t ha-1) than NT (8.35 t ha-1). Although the yield was slightly lower with ZT (9.01 t ha-1) compared to CT, the yield differences were not significant. The influence of tillage on crop yields and N2O emissions most likely reflects the changes which occurred in soil physical (soil moisture, temperature) and biological properties (residue inputs and decomposition rates) resulting from the tillage operations. 
See more from this Division: S06 Soil & Water Management & Conservation
See more from this Session: Agricultural Practices to Increase Nitrogen-Use Efficiency, Carbon Sequestration, and Greenhouse Gas Mitigation: I