Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: August 4, 2008
Publication Date: October 28, 2008
Citation: Franzluebbers, A.J. 2008. Soil organic carbon sequestration with conservation agricultural systems in the southeastern USA. Conservation Agriculture Carbon Offset Consultation, October 28-30, 2009, West Lafayette, IN. Interpretive Summary: Carbon sequestration in soils is a viable strategy to help alleviate the threats from global climate change, as well as to improve the fertility and quality of soil. A scientist from the USDA-Agricultural Research Service in Watkinsville Georgia reviewed literature from the southeastern USA and outlined the potential and limitations of various evaluation techniques to assess soil carbon sequestration. Soil organic carbon sequestration with conservation agriculture in the region can be high (i.e., 1300 to 3400 lbs CO2 per acre per year, depending on management and soil conditions). Conservation tillage, increased cropping system complexity, cover cropping, animal manure application, optimum fertilization, and rotation of crops with pastures are effective strategies to enhance soil organic carbon sequestration. Different evaluation approaches have advantages and disadvantages. Combining field sampling and modeling simulations could provide the most rewarding path forward to get better estimates of soil organic carbon sequestration across a diversity of conservation agricultural systems. This information will be important to policy makers, greenhouse gas trading partners, agricultural extension specialists, and scientists.
Technical Abstract: The southeastern USA has approximately 111 million acres (45 Mha) in agricultural production. This extensive land resource has the potential to sequester soil organic C (SOC), especially following historical conversion of land, first from native forest to intensively cultivated cropland and more recently from intensively cultivated cropland to conservation-tilled cropland or pastureland. This paper reviews the research conducted in this warm, humid region on potential SOC changes with conservation agricultural systems, including from the adoption of conservation tillage, cover cropping, perennial pastures, and integrated crop-livestock systems. Gaps will be identified as to how conservation agricultural systems might affect SOC and emission of greenhouse gases. Further research activities will be suggested to bridge knowledge gaps and move forward with deployment of conservation agricultural systems to increase the sustainability of agriculture in the southeastern USA.