Modeling Soil Carbon in Relation to Management and Climate Change in Some Agroecosytems in Central North America

This chapter utilizes an agroecosystem model to analyze the multifaceted interactions for a set of well characterized agricultural systems in the central US and southern Canada. Given the complexity and multifaceted interactions between management, climate, and CO₂ enrichment, simulation models are useful for exploring possible responses of agricultural systems to global change. The effects of climate and CO₂ change on soil organic matter levels are the result of several interactions affecting the amount of residue returned to the soil and the decomposition rate of residues and soil organic matter. The model results suggest that agroecosystem properties such as soil carbon (C) may be more affected by changes in management than by projected climate changes. In particular, the use of more intensive cropping systems, with reduced fallow frequency and increased residue C inputs had the greatest influence on the soil C balance.