Effects of Climate and Soil Management on Water Use Efficiency: The Role of Modelling

摘要

Water scarcity is the major limitation to crop production in many parts of the world. The water use efficiency (WUE) by which crops use rainfall and irrigation water to produce grains is regulated by dimate and soil conditions during the crop growingseason. This paper briefly depicts how crop WUE is regulated by climate and soil, and demonstrates that crop modelling provides an effective means to benchmark crop WUE as influenced by climate change and soil management practices. Comparison of the modelled WUE against what is observed in the field enables the assessment of WUE and yield gaps, and possible management options to increase both WUE and yield. While water loss by evaporation from soil is a major factor reducing crop WUE, and it increases in drier climates, improvement in technologies to quantify crop transpiration and soil evaporation, and measures to reduce soil evaporation can help to identify approaches to increase crop WUE.