Carbon sequestration in agricultural lands of the United States

Jack A. Morgan is plant physiologist and Feike Dijkstra is post-doc research ecologist at the Rangeland Resources Research Unit, Ronald F. Follett is research leader and soil scientist and Stephen Del Grosso is a soil scientist and ecologist at the Soil Plant Nutrient Research Unit, USDA Agricultural Research Service Northern Plains Area, Fort Collins, Colorado. Leon Hartwell Allen Jr. is soil scientist at the Chemistry Research Unit, USDA Agricultural Research Service South Atlantic Area, Gainesville, Florida. Justin D. Derner is rangeland scientist at the Rangeland Resources Research Unit, USDA Agricultural Research Service Northern Plains Area, Cheyenne, Wyoming. Alan Franzluebbers is ecologist at the Natural Resource Conservation Center, USDA Agricultural Research Service South Atlantic Area, Watkinsville, Georgia. Robert Fry is state conservation agronomist, USDA Natural Resources Conservation Service, Davis, California. Keith Paustian is professor at the Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado. Michele M. Schoeneberger is research leader and soil scientist at the National Agroforestry Center, Lincoln, Nebraska. R educing concentrations of carbon dioxide (CO2) and other greenhouse gases (GHG) in Earth’s atmosphere is identified as one of the most pressing modern-day environmental issues (IPCC 2007). As a signatory country to the United Nations Framework Convention on Climate Change (UNFCCC), the United States is actively engaged in a critical international effort to find solutions to the problems posed by climate change. Agriculture, in addition to being affected by the climate, contributes to climate change through its exchanges of GHG with the atmosphere. Thus, the management of agricultural systems to sequester atmospheric CO2 as soil organic carbon (SOC) and to minimize GHG emissions has been proposed as a partial solution to the climate change problem. In this paper, we discuss the potential role of agriculture in the United States to mitigate climate change through sequestration of carbon (C). We also identify critical knowledge gaps where further research is needed. Carbon enters terrestrial ecosystems, including agriculture, through photosynthesis by green plants that assimilate CO2 FeatUre