The termination date is recognized as a key management factor to enhance cover crops for multiple benefits and to avoid competition with the following cash crop. However, the optimum date depends on annual meteorological conditions, and climate variability induces uncertainty in a decision that needs to be taken every year. One of the most important cover crop benefits is reducing nitrate leaching, a major concern for irrigated agricultural systems and highly affected by the termination date. This study aimed to determine the effects of cover crops and their termination date on the water and N balances of an irrigated Mediterranean agroecosystem under present and future climate conditions. For that purpose, two field experiments were used for inverse calibration and validation of the WAVE model (Water and Agrochemicals in the soil and Vadose Environment), based on continuous soil water content data, soil nitrogen content and crop measurements. The calibrated and validated model was subsequently used in advanced scenario analysis under present and climate change conditions. Under present conditions, a late termination date increased cover crop biomass and subsequently soil water and N depletion. Hence, preemptive competition risk with the main crop was enhanced, but a reduction of nitrate leaching also occurred. The hypothetical planting date of the following cash crop was also an important tool to reduce preemptive competition. Under climate change conditions, the simulations showed that the termination date will be even more important to reduce preemptive competition and nitrate leaching.

终止日期被公认为是关键管理因素，可提高覆盖作物的多重效益，并避免与随后的经济作物竞争。但是，最佳日期取决于年度气象条件，并且气候多变性会导致每年需要做出的决定具有不确定性。覆盖作物最重要的好处之一是减少硝酸盐的淋失，这是灌溉农业系统的一个主要问题，受终止日期的影响很大。这项研究旨在确定在当前和未来气候条件下，覆盖作物及其终止日期对地中海灌溉农业生态系统的水和氮平衡的影响。为了这个目的，根据连续的土壤含水量数据，土壤氮含量和农作物测量结果，使用两个野外实验对WAVE模型（土壤和渗流环境中的水和农药）进行反标定和验证。经过校准和验证的模型随后用于当前和气候变化条件下的高级情景分析。在当前条件下，延迟终止日期增加了农作物生物量，继而增加了土壤水和氮的消耗。因此，与主要作物的先发竞争风险增加了，但硝酸盐浸出的发生也减少了。接下来的经济作物的假想播种日期也是减少先发性竞争的重要工具。在气候变化的情况下