Calibration and evaluation of CSM-CROPGRO-soybean for soybean crop in the southwestern cerrado of Piauí

Calibração e avaliação do CSM-CROPGRO-soybean para cultura da soja no cerrado do sudoeste piauiense

ABSTRACT

The study aimed to calibrate and evaluate the DSSAT CSM-CROPGRO-Soybean model to simulate soybean grain yields in the Cerrado of the Southwestern region of Piaui. To parameterize the model, data from the 2019-2020 crop season was used from an experiment installed in the Serra do Quilombo, in Bom Jesus-PI (9º16'20.3'' S, 44º44'56.9'' O, and altitude 620 m). The BRS 8980 IPRO (BRS 8980), BMX 84I86 (Domínio), BMX 81I81RSF IPRO (Extrema), and BMX 8579 IPRO (Bonus) cultivars were evaluated on three sowing dates (11/29/2019, 01/14/2020, and 01/30/2020). The evaluation was conducted using soybean yield data collected in value for cultivation and use (VCU) experiments conducted by Embrapa Meio-Norte at Celeiro farm, Serra do Quilombo, Bom Jesus, PI, during four harvests and involving 61 genotypes. The best statistical indexes showing the efficiency of the calibration process were observed for the BRS 8980 (first sowing season) and Bônus (third sowing season) cultivars, with R² and D indexes above 0.90. The total biomass production showed high agreement with the measured values, capturing the decrease in production due to the sowing date. The model captured the variability depending on the sowing dates and the yield for simulations of four other agricultural seasons, independent of the season in which the model was calibrated. It was concluded that the model satisfactorily simulated plant growth and soybean grain yield for the conditions of the Cerrado of the Southwestern region of Piaui.

Keywords:
Agricultural modeling; Growth analysis; Sowing time; Climate risk