Developing an eco-physiological process-based model of soybean growth and yield (MATCRO-Soy v.1): Model calibration and evaluation

Abstract. MATCRO-Soy is an eco-physiological process-based crop model for soybean (Glycine max L. (Merr.)). It was developed by modifying the parameters of MATCRO-Rice. The original model, MATCRO-Rice, integrates crop growth processes with a land surface model. These modifications were made using data from literature and field experiments across the world. The reliability of the model was validated extensively by observed soybean yield data across the global, national, and grid cell levels. A moderate correlation was observed between the MATCRO-Soy and FAOSTAT yield data with correlation coefficients of 0.81 (p < 0.001) for the global average yield and 0.512 (p < 0.01) for the global average detrended yield over a 34-year period (1981–2014). Furthermore, the grid-cell level validation revealed that 71 % of the grid cells in the global yield map exhibited a statistically significant correlation between the MATCRO-Soy simulated yield and the derived from observational records. These results highlight the model’s ability to reproduce soybean yield under different environmental conditions, integrating soil water availability and nitrogen fertilizer. MATCRO-soy could enhance our understanding of crop physiology, especially, crop response to climate change and reduce uncertainty in climate change impacts on soybeans.