Abstract The water potential (Ψp), has been widely used as an indicator of plant water status for irrigation management purposes. The simple infrastructure needed for its measurement and its direct relation to basic plant physiological processes, have contributed to the popularity of the methodology. When used for irrigation scheduling, it is commonly assumed that an unavoidable relationship exists between plant transpiration (T), soil water content and Ψp. Nevertheless, it is worth remembering that variations in Ψp are not solely related to changes in soil water content, but are also an expression of the interaction between the plant and its environment. We used a soil-plant-atmosphere-continuum (SPAC) model to highlight the importance of considering such interactions through a series of in silico experiments. Our analysis shows that evaporative demand, the hydraulic architecture of the plant, and the texture and depth of the soil play key roles in the final Ψp observed. To establish irrigation programs based on Ψp, without considering the environmental and plant factors that influence it, can create the paradox of having a plant that suffers greater water stress even when high irrigation volumes are applied. The conclusions from our in silico analysis provide some warnings that should be considered when using Ψp to schedule irrigation.

中文翻译：

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灌溉调度的水势陷阱

摘要 水势 (Ψp) 已被广泛用作灌溉管理中植物水分状况的指标。其测量所需的简单基础设施及其与基本植物生理过程的直接关系，促进了该方法的普及。当用于灌溉调度时，通常假设植物蒸腾作用 (T)、土壤含水量和 Ψp 之间存在不可避免的关系。尽管如此，值得记住的是，Ψp 的变化不仅与土壤含水量的变化有关，而且也是植物与其环境相互作用的表现。我们使用土壤-植物-大气-连续体 (SPAC) 模型来强调通过一系列计算机实验来考虑此类相互作用的重要性。我们的分析表明，蒸发需求、植物的水力结构以及土壤的质地和深度在观察到的最终 Ψp 中起着关键作用。在不考虑影响它的环境和植物因素的情况下，基于 Ψp 建立灌溉计划可能会产生一种悖论，即即使使用高灌溉量，植物也会遭受更大的水分胁迫。我们的计算机分析得出的结论提供了一些警告，在使用 Ψp 安排灌溉时应考虑这些警告。可能会产生一个悖论，即即使使用高灌溉量，植物也会遭受更大的水分压力。我们的计算机分析得出的结论提供了一些警告，在使用 Ψp 安排灌溉时应考虑这些警告。可能会产生一个悖论，即即使使用高灌溉量，植物也会遭受更大的水分压力。我们的计算机分析得出的结论提供了一些警告，在使用 Ψp 安排灌溉时应考虑这些警告。