Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2004
Publication Date: 10/31/2004
Citation: Liebig, M.A., Morgan, J.A., Reeder, S.J., Ellert, B.H., Gollany, H.T., Schuman, G.E. 2004. Greenhouse gas contributions and mitigation potential of agricultural practices in northwestern USA and western Canada. In Agronomy abstracts (No. 4713). ASA, Madison, WI.
Technical Abstract: Concern over human impact on the global environment has generated increased interest in quantifying agricultural contributions to greenhouse gas fluxes. A summary of published research was prepared reviewing management effects on soil organic carbon (C) and carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) fluxes in cropland and rangeland for the northwestern USA and western Canada. Within this region, continuous cropping under no-tillage had the greatest C sequestration rate among dryland cropping systems. Definitive estimates of C sequestration potential for rangelands were difficult to attain due to the diversity of plant communities, soils, and landscapes within rangeland ecosystems. Emissions of N2O within the region were greatest in irrigated cropland, followed by non-irrigated cropland, and rangeland. Rangeland and non-irrigated cropland appear to have potential to act as a sink for atmospheric CH4, but the size of this C sink is difficult to determine given the relative scarcity of assessments. Overall, researchers are challenged to address data gaps in greenhouse gas fluxes between the atmosphere and cropland and rangeland in the northwestern USA and western Canada, as well as integrate such data to determine the net effect of agricultural land on radiative forcing. [GRACEnet Publication]