Abstract The optimization of irrigation strategies with the goal of increasing water utilization efficiency and achieving higher yield is an important farming practice that helps balance groundwater use and food security during water shortage periods in the North China Plain (NCP). In the present study, the AquaCrop model was used to simulate winter wheat yield, evapotranspiration (ET), water productivity (WPET), and irrigation water productivity (IWP) under seven irrigation strategy scenarios and three precipitation categories. The results revealed that the annual precipitation fluctuated significantly over the past 35 years (1981–2015), leading to considerably varied irrigation water requirements with an average of 292 mm. The water consumption intensity of winter wheat tended to shift to the middle growing stage with an increase during the tillering-stem elongation stage and stem elongation-anthesis stage. Two irrigations at the stem elongation and anthesis stages significantly increased yield, WPET, and IWP with values of 7.79 t ha−1, 1.72 kg m-3, and 2.20 kg m-3, respectively, compared with those under lower irrigation frequency treatments. However, a significant decrease in IWP and nonsignificant difference in yield was found when further increasing the irrigation frequency. Combining the yield, WPET, and IWP results, the recommended optimal irrigation strategies for different precipitation categories are one irrigation at the anthesis stage for wet years with yield, WPET, and IWP values of 6.95 t ha−1, 1.49 kg m-3, and 1.73 kg m-3, respectively; two irrigations at the stem elongation and anthesis stages for normal years, which emphasizes meeting the water requirement during the tillering-stem elongation and heading-milk stages; and two irrigations for dry conditions/low precipitation, with emphasis on water requirements during the tillering-stem elongation stage. In conclusion, optimizing irrigation strategies according to precipitation categories can synchronously achieve the goals of increasing water utilization efficiency and achieving higher yield with respect to interannual precipitation variability, which promises to be a sustainable agricultural practice.

中文翻译：

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降水年际变率下华北平原冬小麦产量和水分生产力同步提高的灌溉策略优化

摘要 以提高水资源利用效率和提高产量为目标的灌溉策略优化是华北平原（NCP）缺水时期平衡地下水利用和粮食安全的重要农业实践。在本研究中，AquaCrop 模型用于模拟七种灌溉策略情景和三种降水类别下的冬小麦产量、蒸散量 (ET)、水分生产率 (WPET) 和灌溉用水生产率 (IWP)。结果表明，过去 35 年（1981-2015 年）年降水量波动显着，导致灌溉用水需求差异很大，平均为 292 毫米。冬小麦的耗水强度在分蘖-茎杆伸长期和茎杆伸长-开花期有增加的趋势。与较低灌溉频率处理相比，茎伸长和开花期的两次灌溉显着增加了产量、WPET 和 IWP，分别为 7.79 t ha-1、1.72 kg m-3 和 2.20 kg m-3。然而，当进一步增加灌溉频率时，发现 IWP 显着降低，产量差异不显着。结合产量、WPET 和 IWP 结果，针对不同降水类别推荐的最佳灌溉策略是丰水年开花期的一次灌溉，产量、WPET 和 IWP 值为 6.95 t ha-1、1.49 kg m-3，和 1.73 kg m-3，分别；常年茎杆伸长和开花期两次灌水，强调满足分蘖-茎杆伸长和抽穗-乳期的需水量；以及针对干旱条件/低降水量的两次灌溉，重点是分蘖茎伸长阶段的需水量。总之，根据降水类别优化灌溉策略可以同步实现提高水资源利用效率和实现年际降水变率更高产量的目标，这有望成为一种可持续的农业实践。重点是分蘖茎伸长阶段的水分需求。总之，根据降水类别优化灌溉策略可以同步实现提高水资源利用效率和实现年际降水变率更高产量的目标，这有望成为一种可持续的农业实践。重点是分蘖茎伸长阶段的水分需求。总之，根据降水类别优化灌溉策略可以同步实现提高水资源利用效率和实现年际降水变率更高产量的目标，这有望成为一种可持续的农业实践。