LP2M2E, Département de Physique Appliquée, Faculté des Sciences et Techniques, Université Cadi Ayyad, (UCAM), Marrakech, Morocco.
Centre d'Etudes Spatiales de la BIOsphère (CESBIO), Institut de Recherche pour le Développement (IRD), Toulouse, France.
Sci Rep. 2019 Dec 16;9(1):19142. doi: 10.1038/s41598-019-55251-2.
The present work aims to quantify the impact of climate change (CC) on the grain yields of irrigated cereals and their water requirements in the Tensift region of Morocco. The Med-CORDEX (MEDiterranean COordinated Regional Climate Downscaling EXperiment) ensemble runs under scenarios RCP4.5 (Representative Concentration Pathway) and RCP8.5 are first evaluated and disaggregated using the quantile-quantile approach. The impact of CC on the duration of the main wheat phenological stages based on the degree-day approach is then analyzed. The results show that the rise in air temperature causes a shortening of the development cycle of up to 50 days. The impacts of rising temperature and changes in precipitation on wheat yields are next evaluated, based on the AquaCrop model, both with and without taking into account the fertilizing effect of CO. As expected, optimal wheat yields will decrease on the order of 7 to 30% if CO concentration rise is not considered. The fertilizing effect of CO can counterbalance yield losses, since optimal yields could increase by 7% and 13% respectively at mid-century for the RCP4.5 and RCP8.5 scenarios. Finally, water requirements are expected to decrease by 13 to 42%, mainly in response to the shortening of the cycle. This decrease is associated with a change in temporal patterns, with the requirement peak coming two months earlier than under current conditions.
本研究旨在量化气候变化（CC）对摩洛哥Tensift 地区灌溉谷物的粮食产量及其水分需求的影响。首先，利用分位数-分位数方法对 Med-CORDEX（地中海协调区域气候降尺度实验）集合在 RCP4.5（代表性浓度路径）和 RCP8.5 情景下的运行结果进行评估和离散化。然后，基于度日方法分析 CC 对主要小麦物候阶段持续时间的影响。结果表明，气温升高导致发育周期缩短多达 50 天。接下来，基于 AquaCrop 模型评估了温度升高和降水变化对小麦产量的影响，同时考虑和不考虑 CO 的施肥效应。不出所料，如果不考虑 CO 浓度上升，最佳小麦产量将减少 7%至 30%。CO 的施肥效应可以抵消产量损失，因为在 RCP4.5 和 RCP8.5 情景下，到本世纪中叶，最佳产量将分别增加 7%和 13%。最后，预计水分需求将减少 13%至 42%，这主要是由于周期缩短所致。这种减少与时间模式的变化有关，需求峰值比当前条件下提前两个月出现。
