ABSTRACT
This chapter describes 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 Central US The study region extends from the Great Lakes to Eastern Colorado, and from the Canadian border to northern Arkansas, thereby including portions of agricultural regions of the Cornbelt, Great Plains, and Great Lakes. Parton developed the CENTURY model to simulate the dynamics of carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) in cultivated and uncultivated grassland soils. CENTURY has submodels for estimating plant growth and soil water balance. The Resource Adjustment Modeling System (RAMS) provides the CENTURY model information about production patterns and production practices throughout the study region. The project modeling methodology was developed to integrate the issues of spatial detail of required data, modeling of agricultural practices, estimation of current or initial soil carbon conditions, and procedures for assessment of alternative future conditions resulting from policy scenarios.
