干旱区生态环境知识资源中心

This study was conducted to determine crop water sensitivity during growth stages, and puts forward an optimum water supply schedule for crops in the Loess Plateau region. Effects of water use on pro-ductivity during growth of winter wheat [Triticum aestivum L] and spring corn [Zea mays] were investigated at Changwu Agricultural Experiment Station of the Chinese Academy of Sciences. Water sensitivity of wheat was calculated using the Jensen model. Results indicated that the Jensen models water sensitivity index W reaches its highest value during the seedling- vegetative phase, its second highest value during booting to heading, and third highest during heading to milk phase. So the relative importance of irrigation corresponds with these results. Optimum irrigation for winter wheat should be maintained before winter and during booting to heading stage. For corn, lambda reaches it's highest value during booting to heading and its second highest value during heading to milk phase, indicating the relative importance of irrigation applications.