Estimated productivity of sugarcane through the Agro-Ecological Zone method

ABSTRACT The estimate of the potential sugarcane productivity through agroclimatic models aids in the agricultural planning of the crops and the quantification of the yield for a given region. For these estimated values to be considered robust there is a need for validating the performance of such models in different areas and agricultural varieties. Hence, the aim of this study was to validate the Agro-Ecological Zone (AEZ) method with fifteen sugarcane varieties in the region of the Vale do São Patrício, state of Goiás, Brazil. We evaluated the data referring to the cane-plant (one-and-a-half-year sugarcane), as well as the first and second sugarcane ratoons (both with one-year cycles) in an irrigated and dry farming system. The productivities obtained in dry farming were corrected due to the occurrence of a water deficit in the crop. The results indicated that the AEZ method presented productivity estimates more satisfactory for the one-year cultivation cycles (ratoon cycles) for all varieties studied, with the model adjusting best to the CTC15 variety (RMSE = 8.70 t ha-1; MAE = 6.05 t ha-1; d = 0.99).

摘要：通过农业气候模型估算甘蔗潜在生产力，可为作物农业规划制定及特定区域的产量量化提供支撑。为确保此类估算结果具备可靠性，需在不同区域与农业品种中验证这类模型的应用性能。据此，本研究以巴西戈亚斯州（Goiás）圣帕特里西奥谷（Vale do São Patrício）区域为研究区，针对15个甘蔗品种验证农业生态区（Agro-Ecological Zone, AEZ）方法的有效性。本研究评估了新植蔗（种植周期1.5年）、头季宿根蔗与第二季宿根蔗（均为1年周期）在灌溉与旱作两种种植体系下的相关数据。针对旱作体系中作物发生水分亏缺的情况，对测得的生产力数据进行了校正。结果表明，针对所有供试品种的1年周期栽培（宿根周期），农业生态区方法的生产力估算结果更为理想；其中该模型对CTC15品种的适配效果最优，其均方根误差（Root Mean Square Error, RMSE）为8.70 t·ha⁻¹、平均绝对误差（Mean Absolute Error, MAE）为6.05 t·ha⁻¹、一致性系数d为0.99。