The AquaCrop model was evaluated considering a data set from a cowpea (BR3-Tracuateua cultivar) cultivation in Castanhal/Brazil under different irrigations during the reproductive phase, which is sensitive to water deficit. Data on leaf area index (LAI), soil water content (SWC), biomass, and final yield of two harvests were used for model calibration (2013) and validation (2014). LAI data were used for parameterization of canopy cover (CC), and some crop parameters obtained in the field. The model was also used to evaluate the impacts of sowing dates, as well as the strategy of using an economical irrigation threshold (60% of Readily Available Water) on the water use and crop yield. Regarding the results after parameterization of the canopy cover curve, the model efficiency index (EF) presented a satisfactory performance (0.98), which is due to the high correlation coefficient (R² = 0.99) between the simulated and observed values and the low values of normalized root mean square error (NRMSE < 6.33%). For model performance in simulating SWC, there was high efficiency (EF > 0.70) for all treatments, with low estimated errors and NRMSE representing 8.12% of mean SWC observations during validation, indicating high precision for simulation of biomass and cowpea yield. The model performance index ranged from 0.92 to 0.94 for biomass and from 0.92 to 0.99 for final yield. These results showed that AquaCrop is suitable for simulating biomass production and yield of cowpea. Additionally, sowing in early April is appropriate for better water use and productivity and the tested irrigation threshold can be indicated to significantly improve final crop yields.

评估AquaCrop模型时考虑了在生育期不同灌溉条件下在巴西Castanhal /巴西种植cow豆（BR3-Tracuateua栽培品种）的数据集，该数据集对缺水敏感。使用叶面积指数（LAI），土壤水分（SWC），生物量和两次收获的最终产量的数据进行模型校准（2013年）和验证（2014年）。LAI数据用于冠层覆盖（CC）的参数化，以及在田间获得的一些作物参数。该模型还用于评估播种期的影响，以及使用经济灌溉阈值（可用水的60％）对用水和作物产量的策略。关于对冠层覆盖曲线进行参数化后的结果，模型效率指数（EF）表现出令人满意的性能（0.98），² = 0.99）在模拟值和观察值之间以及标准化均方根误差的低值（NRMSE <6.33％）之间。对于模拟SWC的模型性能，所有处理均具有较高的效率（EF> 0.70），估计误差低，并且NRMSE代表验证期间平均SWC观测值的8.12％，表明模拟生物量和cow豆产量的高精度。对于生物质，模型性能指数的范围为0.92至0.94，对于最终产量，模型性能指数的范围为0.92至0.99。这些结果表明，AquaCrop适用于模拟biomass豆的生物量生产和产量。此外，4月初的播种适合于更好地利用水和提高生产力，可以指示出经过测试的灌溉阈值，可以显着提高最终作物的产量。