Abstract: The CENTURY model, designed to predict soil C, N, P, and S dynamics in a range of ecosystems, is one of the most famous biogeochemical models in the world. The research reported here systematically examines the operating mechanisms and processes of the CENTURY model, and research data on results of soil organic carbon were analyzed and collated for grassland, farmland and forest ecosystems using this model. It was found that soil texture and soil nutrient levels are key factors influencing the application of the CENTURY model in grassland ecosystems, and that the model has high predictive accuracy in desert grassland. Agricultural management is one of the factors most strongly affecting soil organic carbon (SOC) simulation accuracy. The SOC simulation accuracy was higher in intercrop systems than in monocrop scenarios. CENTURY had structural defects in simulating soil organic matter in the litter layer of forest ecosystems; hence the CENTURY model performs better in the simulation of grassland and farmland systems than when simulating forest ecosystems. Since the CENTURY model was originally developed for work on grassland ecosystems, its model parameters are more universally applicable to grassland ecosystems in different regions. Excessive human intervention would increase the uncertainty factor in CENTURY modeling of agro-ecosystems, potentially resulting in instable simulation results. The simulation accuracy could be substantially improved through collecting data on and accurately accounting for historical farm system and management methodologies practiced, when performing the simulation. The simulation results for forest ecosystems can be used for the formulation of management measures. In addition, scaling up from single-point simulation to the regional level could be achieved by the integration of CENTURY model results into a GIS approach.

Key words: CENTURY model, soil organic carbon, ecosystem