Research on Water Use Efficiency Based on the Theory of Virtual Water: A Case Study in Baoji Gorge Irrigation Region

摘要

Based on the theory, of virtual water, agricultural water use efficiency of Baoji Gorge irrigation region in Shaanxi Province was researched and several indicators to evaluate the water use efficiency in agriculture have been given. It could be known from the research that the key of water-saving agriculture is to reduce water invalid losses. Not only water consumption not in crop photosynthesis should be saved, but also over water consumed because crop yield is less than their production potential should be reduced. In northwest China, because multiple cropping index increased with the developing of irrigation, resources of photosynthetic radiation and heat in fallow season of cropland would be more fully used, the invalid evaporation on bare soil turns into effectively crop transpiration, water use efficiency of agriculture enhances.