Abstract:Abstract: Water shortage is a serious problem threatening sustainable agricultural development in the North China Plain, where winter wheat (Triticum aestivum L.) is the largest water-consuming crop. Water-saving technique is one of the most important components in maintaining wheat cultivation system with sustainable production in this area. The objective of this study was to optimize irrigation schedule in order to obtain high yield and water use efficiency in wheat. Field experiments were conducted with the cultivar of Jimai 22 under high-fertilizer soil conditions during 2007—2009 years. The irrigation treatments were designed four supplemental irrigations based on average relative soil moisture contents at 0—140 cm layers, at sowing, jointing, and anthesis stages(80%, 65%, and 65% for treatment W0; 80%, 70%, and 70% for treatment W1; 80%, 80%, and 80% for treatment W2; 90%, 80%, and 80% for treatment W3, respectively), to examine effects of different irrigation treatments on nitrogen accumulation and translocation, grain yield, water use efficiency, and soil nitrate nitrogen leaching in winter wheat. The results showed that: (1) Plant nitrogen accumulation of wheat at maturity for treatment W1 was the highest, following by W3, W0, and W2 (P<0.05). The rate of nitrogen distribution to grain for treatment W2 was significantly lower than W1, and the differences among treatment W0, W1, and W3 were no significant. Nitrogen accumulation amount in vegetative organs at anthesis and maturity, nitrogen translocation of vegetative organs to grain, and grain nitrogen accumulation amount at maturity all showed the order of W1>W3>W2>W0 (P<0.05). (2)Nitrate nitrogen content in 0—200 cm layers decreased first, increased then, and decreased again with wheat growth process progress, reaching its lowest content at jointing stage. At maturity stage, soil nitrate nitrogen content in 0—200 cm soil layers of treatments W0 and W1 were significantly lower, while those in 120—200 cm soil layers of treatments W2 and W3 were higher. (3)Nitrogen uptake, use efficiency, and partial productivity of treatment W0 were the lowest. Nitrogen use efficiency increased first, decreased then with irrigation amount increasing. Nitrogen uptake and use efficiency of treatment W1 was higher while its nitrogen partial productivity was the highest. Water use efficiency of treatment W0 was higher than those of other treatments. However, grain yield was the lowest for treatment W0. In two years, grain yield, irrigation water use efficiency, and irrigation benefit for the three irrigation treatments decreased significantly when more water was supplied. Under the present experimental condition, the W1 regime was considered optimal irrigation treatment, which 43.83 and 13.77 mm of water were supplied during 2007—2008 and 2008—2009 years, respectively.