Effects of Irrigation Scheduling on Development and Water Use Efficiency in Winter Wheat

An irrigation experiment was conducted in winter wheat in Huantai county, Shandong province in 1998～1999 growing season. Development data showed that growth process of winter wheat may be promoted by reducing irrigation quota. Plant height was affected notably by irrigation in jointing stage. Leaf area index, dry matter amount above ground, and root capacity increased with irrigation quota increasing. Over 80% of roots distributed in soil layer of 0～20 cm. Water use efficiency decreased gradually with irrigation times and quota increasing. The highest yield of 7716.7 kg/hm 2, water use efficiency of 15.92 kg/(hm 2·mm), margin efficiency of 43.12 kg/mm and average yield increment per irrigation of 851.65 kg/hm 2 all was achieved in irrigation treatment with three irrigations: before over winter, jointing, and flowering.