Greenhouse gas emission in Alberta crop production sector: Opportunities and challenge

It is widely accepted that atmospheric build-up of CO2, N2O and CH4 is, in part, associated with the agriculture industry. Next to Ontario, Alberta is the second largest agriculture province ($6.6 billion in farm cash receipts) in Canada. Reduction of GHG in the agriculture sector of Alberta will play a significant role to fulfill Canada's Kyoto GHG reduction commitment of 6% below 1990 levels. Research in Alberta on GHG reduction, beginning in the middle 1980's, examined various topics including: enhanced carbon (C) sequestration in soil through balanced fertility management, residue retention and reduced tillage; fate of autumn-applied nitrogen (N) and subsequent denitrification during the spring thaw; denitrification rate in relation to landscape position; rate, time and methods of nitrogen application; nitrification inhibitors and controlled release fertilizers. The objectives of this paper are to present our summarized past research results on C sequestration and N2O emission, and to illustrate the preliminary attempts to scale up the results in a large geographical areas. The results showed that N application, straw retention and no tillage practice can increase organic C in soil. However, the amount of C sequestered varies with soil type. The amount of N2O emission from arable land are strongly influenced by soil water content, N management, and slope position. We have developed a GIS model to identify the high N2O emission area, which may serve as a tool to help producers to reduce N2O emissions. The findings suggest that future research should be focused on quantifying the rate and capacity of C sequestration in different soil-climatic zones and further development of GIS tool in the reduction of N2O emissions.