S. S. Malhi¹, R. L. Lemke², J. J. Schoenau³, F. Selles⁴, D. Leach¹,

M. Stumborg⁵, D. James⁵ and D. L. Hahn²

¹Agriculture and Agri-Food Canada, Melfort, SK, Canada (E-mail: sukhdev.malhi@agr.gc.ca)

²Agriculture and Agri-Food Canada, Saskatoon, SK, Canada

³Department of Soil Science, University of Saskatchewan, Saskatoon, SK, Canada

⁴Agriculture and Agri-Food Canada, Brandon, MB, Canada

⁵Agriculture and Agri-Food Canada, Swift Current, SK, Canada

Abstract

Field experiments were conducted in Saskatchewan to determine the impact of tillage, crop residue, fertilizer and manure on nitrous oxide (N₂O) emissions and ammonia (NH₃) volatilization. In the 8-year (1998-2005) study with no-tillage - NT and conventional tillage - CT), straw retained and straw removed, and 0, 40, 80, and 120 kg N ha^-1, N₂0 emissions were usually higher under CT than NT. In the alfalfa termination study (2003-2007) with herbicide – NT, tillage, and herbicide + tillage termination methods, after first cut, after second cut, and spring at 0, 40, 80, and 120 kg N ha^-1, herbicide-NT termination method had the lowest N₂O-N loss in the termination year or in the first crop year following termination, while tillage had the highest N₂O-N loss. In the polymer-coated urea (PCU) 3-year study, N₂O-N loss was reduced by using PCU compared to urea. In the liquid swine manure (LSM) 3-year study with LSM application at 3000, 6000 and 9000 L ha^-1 for 1x (annually), 2x (after every 2 years) and 3x (after every 3 years) rates, respectively, N₂O emissions from LSM were higher than urea, and LSM 3x rate higher than 1x rate. In the 3-year study (2006-2008) at two sites with application of anaerobically digested swine manure (ADSM) and conventionally treated swine manure (CTSM) at 1x and 3x rates in autumn and spring, and annual spring application of urea-ammonium nitrate (UAN) solution at 1x rate, NH₃ loss from ADSM was equal to CTSM, except for CTSM at 3x rate it was higher than other treatments. Nitrous oxide losses were highest from CTSM > ADSM = UAN. In conclusion, proper soil, crop, fertilizer and manure management practices can reduce the potential for GHG emissions from soil to the atmosphere, and this is good for the environment.   

Mode of Presentation: Poster