Performance of the AquaCrop model for the wheat crop in the subtropical zone in Southern Brazil

Abstract: The objective of this work was to calibrate and validate the AquaCrop model for the wheat (Triticum aestivum) crop in the Campos Gerais region, in Southern Brazil. Five cultivars were evaluated in the harvests from 2007 to 2017. The input data for AquaCrop - related to climate, crop, soil, and soil management -, collected in the field, were obtained from the database of Fundação ABC and from the literature. From 35 to 43% of total harvests were selected for calibration, and the remaining, for validation. Calibration was performed for the parameters most sensitive to crop potential yield penalty. The simulated yields were compared with those observed in the field through simple linear regression analysis, root mean square error (RMSE), Pearson’s correlation coefficient (r), the index of agreement (d), and the performance index (c). Calibration showed good results (RMSE ≤ 609.78 kg ha-1; r ≥ 0.72; d ≥ 0.80) for all assessed cultivars and locations, but validation did not have the same performance (c ≤ 0.46). The attempted adjustment, considering the range of calibrated parameters in the harvests, indicated “very good” and “excellent” performances (Supera and Quartzo, respectively) for the cultivars in Castro and “tolerable” to “excellent” in Ponta Grossa.

摘要：本研究旨在针对巴西南部坎波斯热赖斯（Campos Gerais）地区的普通小麦（Triticum aestivum）校准并验证AquaCrop模型（AquaCrop）。本研究于2007至2017年的收获季中评估了5个小麦品种。AquaCrop模型（AquaCrop）的输入数据涵盖气候、作物、土壤及土壤管理相关参数，由野外实地采集所得，获取自ABC基金会（Fundação ABC）数据库及公开学术文献。研究选取总收获季数的35%至43%用于模型校准，剩余部分用于模型验证。校准过程针对对作物潜在产量损失最为敏感的参数开展。通过简单线性回归分析、均方根误差（root mean square error, RMSE）、皮尔逊相关系数（Pearson’s correlation coefficient, r）、一致性指数（index of agreement, d）以及性能指数（performance index, c），将模型模拟产量与田间实测产量进行对比。校准结果显示，所有供试品种及试验点位的模拟效果良好（RMSE ≤ 609.78 kg·ha⁻¹；r ≥ 0.72；d ≥ 0.80），但验证阶段的模型性能未达同等水平（c ≤ 0.46）。结合校准参数范围对收获季数据进行调整后，结果显示卡斯特罗（Castro）地区的供试品种Supera与Quartzo分别达到"极佳"与"优秀"的性能表现，而蓬塔格罗萨（Ponta Grossa）地区的模型性能则介于"可接受"至"优秀"之间。