Improving agricultural water productivity to ensure food security in China under changing environment: From research to practice

Irrigation is an important measure for increasing grain production. Improving water use efficiency in agriculture is expected to play a very important role in ensuring food and water security in China, since there is a serious problem between food supply and limited water resources in China. The present state and future trend of water and food security in China were analyzed, while the importance of irrigation in ensuring China food security was highlighted based on the analysis of the evolution of irrigation water productivity in recent 60 years and its relationships with changes of crop yield, cropping pattern, fertilization and irrigation water use. Research progresses and practical application on high-efficient agricultural water use in China were introduced, and two successful cases of improving agricultural water productivity in China were presented, one was to improve crop water use efficiency by the novel irrigation method based on crop physiological responses, and the other was to improve the regional water productivity by the integrative methods in the Shiyang River Basin of Northwest China. The major research areas needed to focus on in the future were discussed, which include responses of crop water demand to changing environment and associated spatio-temporal optimization of water allocation, multi-processes hydrologic cycle of irrigated land under strong influences of human activities, integrated measures for improving multi-scale agricultural water use efficiency, and interactions between grain production, water resources and ecological system and its sustainability analysis in a systematic way.