Updating carbon pool initialization within DSSAT‐CENTURY

Abstract Allocation of C to conceptual C pools in the Decision Support System for Agrotechnology Transfer (DSSAT)‐CENTURY model determines the proportion of organic matter available for nutrient cycling. DSSAT‐CENTURY defaults to a pedotransfer function if relevant field history is unknown or a stable C value has not been provided. The current pedotransfer function only requires silt and clay content to predict stable C and was derived from a dataset of coarse‐textured soils. We tested the current pedotransfer function against a new function derived from a soils dataset with a larger range of texture and soil organic carbon; both functions were used to predict stable C for an independent global soils dataset. The current pedotransfer function overestimated stable carbon for 26% of soil samples compared to 10% for the new function. Incorporating multiple region or texture‐specific pedotransfer functions into the C initialization subroutine is likely merited to improve simulation of C dynamics over time.