ABSTRACT
This chapter focuses on the soil carbon modeling procedures used to evaluate the impacts of cropping practices, crop rotations, tillage practices, soils, and climate on soil carbon levels in the Central United States. It summarizes the final study results, and thereby serves as an update of the preliminary results presented at the April 1993 International Symposium in Columbus, Ohio. The final study results were published as an Environmental Protection Agency (EPA) Research Report entitled "Assessment of Alternative Management Practices and Policies Affecting Soil Carbon in Agroecosystems of the Central United States". The primary components of the modeling system include: the Resource Adjustment Modeling System; the CENTURY soil carbon model; the EPA Agroecosystem Carbon Pools database and the geographical information system capabilities EPA, Athens, GA. These final study results provide a strong indication that agricultural trends are leading to generally improved soil fertility and increased soil organic carbon sequestration even without specific policies designed to promote the objectives.
