河套春小麦灌溉制度优化及降水利用效率响应研究OA

Optimizing irrigation regimes can enhance precipitation use efficiency,accurately quantifying this effect is crucial for alleviating water scarcity and supply-demand conflicts in arid regions.Focusing on spring wheat in the Hetao Irrigation District,this study set six levels of lower soil moisture limits dur-ing critical growth stages.Irrigation regime optimization was investigated at both the experimental scale and regional scales under different groundwater depths,and its effects on yield,water productivity,and precipitation use efficiency were analyzed.The results show that the suitable lower limits of soil moisture for spring wheat during the seedling-jointing,jointing-heading,and heading-filling stages are 65%,70%,and 65%of field capacity,respectively.Compared with the current irrigation regime,the opti-mized irrigation regime can significantly reduce deep percolation and moderately increase groundwater re-charge.Specifically,under scenarios where the average groundwater depth is less than 2.5 m,close to 2.5 m,and greater than 2.5 m,precipitation use efficiency increases to 83.1%,96.4%,and 100.0%,respectively.This indicates that the optimized irrigation regime can enhance precipitation use efficiency even in areas with shallow groundwater depths.Based on the actual conditions of spring wheat planting area and groundwater depth in the Hetao region,a preliminary estimate suggests that optimized irrigation practices can increase precipitation use by approximately 1.76×106 m3.These findings can provide a theoretical basis and data support for alleviating water scarcity and achieving efficient use of precipitation resources in arid regions.