Assessment of Sowing Dates and Plant Densities Using the CSM-CROPGRO-Soybean Model Under Cerrado Climatic Conditions

Crop management strategies are essential to achieve maximum crop yields. In this context, crop models can be used to understand yield variability. The aim of this study was to evaluate historical yields based on the sowing date and plant density. Field experiments were conducted during two growing seasons at two locations using a maturity group 7.6 cultivar, with distinct sowing dates and plant densities (10 to 50 plants m−2). After calibration, the model was applied to historical weather data (1990–2022) for nine locations across the Cerrado biome. The CSM-CROPGRO-Soybean model simulated soybean development with biases for physiological maturity of +8 and −7 days for calibration and evaluation, respectively. The relative root mean square error for yield was below 14%. Similar trends were observed for the leaf area index (LAI) across plant densities, while biomass partitioning proved to be a limiting component, mainly for stem biomass. The optimal plant population ranged from 20 to 30 plants m−2, whereas a low density (10 plants m−2) resulted in higher yield losses under late sowing. Therefore, the use of crop simulation models is an effective tool to understand and optimize sowing dates and plant densities under historical climatic conditions in the Cerrado.