Paustian, Keith (Colorado State Univ., NREL, Colorado State Univ., Ft. Collins, CO, 80523; Phone: 970-491-1547; Email: keithp@nrel.colostate.edu)

Simulating Historical and Current Soil C Dynamics in US Agricultural Systems

K. Paustian *, S. Williams, M. Easter, K. Killian, S. Ogle

Regional- and national-scale information on soil C changes are required for estimating greenhouse gas inventories and for assessing greenhouse gas mitigation practices and policies. We describe a methodology for estimating historical and current changes in soil C stocks in agricultural soils in the US. The method is comprised of data base servers incorporating spatial and tabular data from a variety of sources and executive programs for computation within a parallel computing environment. Input data sources, including climate, soil properties, historical land use and past and present soil and crop management practices are documented. Model sensitivities to uncertainties in historical land use practices are quantified and model predictions of historical and present soil C emissions and sinks are discussed.