Knowledge-driven "smart" irrigation proposes to achieve explicitly targeted crop yield and/or irrigation water use efficiency (WUE). A coupled crop growth and soil water transport model was established and applied to schedule irrigation for drip-irrigated and film-mulched maize through numerical simulation. By designing various scenarios with either a constant or variable threshold of plant water deficit index (PWDI) to initiate irrigation, the quantitative relationship between PWDI threshold and the corresponding yield and WUE was investigated with acceptable errors between the measured and simulated values (R² > 0.85). The model allowed determination of PWDI thresholds designed to reach specific combinations of yield and WUE to consider actual conditions such as availability and cost of water resources. Regulated deficit irrigation with a variable threshold, considering variability of physiological response to water stress, was superior to a constant PWDI threshold in improving WUE. A constant PWDI threshold of 0.54 and 45 threshold combinations among various growth stages were suggested to obtain same relative values of yield and WUE. Numerical simulation has the potential to provide reliable dynamic information regarding soil water and crop growth, necessary for smart irrigation scheduling, due to its ability in integrating the effects of environmental conditions and economic considerations and, as such, should be further studied to enhance simulation accuracy and subsequently to optimize irrigation scheduling under complex situations.

知识驱动的“智能”灌溉建议实现明确的目标作物产量和/或灌溉用水效率（WUE）。建立了作物生长与土壤水分运移的耦合模型，并通过数值模拟将其应用于滴灌和覆膜玉米的灌溉计划。通过设计具有恒定或可变植物水分亏缺指数（PWDI）阈值的各种方案来启动灌溉，研究了PWDI阈值与相应产量和WUE之间的定量关系，并在测量值与模拟值之间存在可接受的误差（R ²> 0.85）。该模型允许确定PWDI阈值，该阈值旨在达到产量和WUE的特定组合，以考虑实际条件，例如水资源的可获得性和成本。考虑到对水分胁迫的生理响应的可变性，可变阈值的调节性亏水灌溉在提高WUE方面优于恒定的PWDI阈值。建议在各个生长期之间使用恒定的PWDI阈值0.54和45阈值组合以获得相同的相对产量和WUE值。数值模拟具有集成环境条件和经济考虑因素的能力，因此有可能提供可靠的动态信息，这是智能灌溉计划所必需的有关土壤水和作物生长的信息，因此，