Franzluebbers, Alan (USDA-ARS, Watkinsville, GA, 30677; Phone: 706-769-5631; Fax: 706-769-8962; Email: afranz@uga.edu)

Greenhouse Gas Contributions and Mitigation Potential in Agricultural Regions of North America

A.J. Franzluebbers *, R.F. Follett, E.G. Gregorich, J.M.F. Johnson, M.A. Liebig, D.A. Martens, S.J. Del Grosso, M.D. Jawson

Agricultural land in North America is managed with a diversity of techniques and technologies to achieve a wide range of goals. Overlaying this management diversity onto an environmentally and ecologically diverse landscape leads to a complex arrangement of how agricultural management systems might contribute to and mitigate greenhouse gas emissions. This paper reviews regionally-specific information available on soil organic C sequestration and greenhouse gas emission in agriculture systems of North America. Adoption of conservation tillage has been widely implemented and mean values of soil organic C sequestration among the five major regions ranged from -0.07 Mg C/ha/yr in the northeast to 0.48 Mg C/ha/yr in the southeast. Actual field measurements of nitrous oxide emission and methane uptake by soils have not been widely determined, and this lack of information suggests a key area requiring further research. Modeling efforts have allowed estimation of regional differences in net global warming potential of greenhouse gas emission in agricultural systems. Research and implementation needs to better describe greenhouse gas contributions and mitigation potential of agricultural systems in North America have been identified.