Studies on the use of deficit irrigation and application of models for estimating agronomic performance of crops can help in more sustainable agricultural managements. The objective of this study was to evaluate the effect of irrigation levels on the agronomic performance of white oat (Avena sativa L.) and accuracy of the CERES-Barley model in simulating white oat growth and yield, as well as performing long-term simulation to identify the best sowing time for each irrigation management. The experiment consisted of five irrigation levels (11%, 31%, 60%, 87%, and 100%), being conducted in two agricultural years in southeastern Brazil. The model was calibrated with data of the treatment without water deficit (100%) of the first year and validated with the data of the other treatments in the 2 years. Long-term analyses, with a historical series of 16 years, were performed to recommend the best sowing dates for each irrigation management. Deficit irrigation linearly reduces the agronomic performance of white oat. The high accuracy of white oat yield estimation (R² = 0.86; RMSE = 616 kg ha⁻¹) using the CERES-Barley model allowed the long-term simulation for establishing the best sowing date for each irrigation level. For higher irrigation levels, sowing in periods with lower temperature (May and June) is more appropriate, as the 1 °C increment in the average temperature before flowering reduces crop yield by 600 kg ha⁻¹. At irrigation levels with higher deficit, sowing in periods with higher rainfall (March and April) promotes higher crop yield.

研究利用亏缺灌溉和应用模型来估计作物的农艺性能，有助于实现更可持续的农业管理。本研究的目的是评估灌溉水平对白燕麦（Avena sativaL.) 和 CERES-Barley 模型在模拟白燕麦生长和产量方面的准确性，以及执行长期模拟以确定每种灌溉管理的最佳播种时间。该试验包括五个灌溉水平（11%、31%、60%、87% 和 100%），在巴西东南部的两个农业年中进行。该模型用第一年无缺水（100%）处理的数据进行校准，并用第二年其他处理的数据进行验证。进行了具有 16 年历史序列的长期分析，以推荐每种灌溉管理的最佳播种日期。缺水灌溉会线性降低白燕麦的农艺性能。白燕麦产量估算的高精度（R ² = 0.86；RMSE = 616 kg ha ^-1) 使用 CERES-Barley 模型可以进行长期模拟，以确定每个灌溉水平的最佳播种日期。对于较高的灌溉水平，在温度较低的时期（5 月和 6 月）播种更合适，因为开花前平均温度升高 1 °C 会使作物产量减少 600 kg ha ^-1。在赤字较高的灌溉水平上，在降雨量较高的时期（3 月和 4 月）播种可提高作物产量。