Effect Of Delayed Irrigation At Jointing Stage On Grain Yield And Winter Wheat In Wide-precision Planting Pattern

North China Plain is the main winter wheat production area in China; however, in recent years, because of climate change, water pollution, and other reasons made water resources sharp shortage, especially in agricultural water. In the face of the increasingly nervous of the serious situation of water resources, how to improve the winter wheat water use efficiency and save water at the same time, and how to synchronize improve the winter wheat grain yields are urgent problems to be solved under the condition of limited water resources.In order to investigate the optimal water-saving and high-efficient irrigation regimes of winter wheat, during2012～2013winter wheat growing season, at Experimental Station of Shandong Agricultural University,2types of planting patterns (wide-precision planting pattern and conventional-cultivation planting pattern) and3different irrigation regimes (no irrigation at any time during the growing season, irrigated60.0mm at jointing stage, and irrigated60.0mm at10days after the jointing stage, respectively) were conducted, to study the effect of delayed irrigation at jointing stage on soil moisture, canopy temperature, evaporation, field microclimate, individual stems, plant height, leaf area index (LAI), dry matter accumulation, photosynthetic rate, transpiration rate, Photosynthesis active radiation (PAR), chlorophyll content index (CCI), grain yield, and water use efficiency of winter wheat in wide-precision planting pattern.The results showed that:(1) Effect of delayed irrigation at jointing stage on water consumption of winter wheat in wide-precision planting pattern.Under the condition of irrigated60.0mm, compared with the other treatments, in wide-precision planting pattern, delayed irrigation at jointing stage could significantly decrease the water consumption, and the phase water consumption both in jointing～heading and heading-filling stages was also decreased. In wide-precision planting pattern, no matter irrigated at jointing stage or delayed irrigation at jointing stage, there’re no significant difference was found both in temperature and humidity; however, in the late winter wheat growth stages, delayed irrigation at jointing stage could significantly increase the canopy temperature, reduce the evaporation amount, thereby reduce the invalid evaporation of soil water in wide- precision planting pattern. Hence, in the late winter wheat growth stages, under the condition of delayed irrigation at jointing stage, water consumption in wide-precision planting pattern was much effectively than that in conventional-cultivation planting pattern.(2) Effect of delayed irrigation at jointing stage on winter wheat grain yield in wide-precision planting pattern.Delayed irrigation at jointing stage could significantly increase winter wheat grain yield in wide-precision planting pattern. In yield components, delayed irrigation at jointing stage had not significantly increased winter wheat spike numbers in wide-precision planting pattern, and delayed irrigation at jointing stage had no significant effect on1000-grain weight of the both planting patterns; however, delayed irrigation at jointing stage could significantly increase winter wheat kernels numbers per spike in wide-precision planting pattern. Delayed irrigation at jointing stage had not significantly increased individual stems of winter wheat in wide-precision planting pattern, but delayed irrigation at jointing stage could increase LAI, plant height, and the dry matter accumulation amount of winter wheat in wide-precision planting pattern. In the late winter wheat growth stages, delayed irrigation at jointing stage could increase CC1in wide-precision planting pattern, and delayed irrigation at jointing stage could also increase PAR canopy capture ratio of winter wheat, which promote the winter wheat flag leaf photosynthetic rate, and promote the transfer of the dry matter accumulation amount, thereby increase winter wheat grain yield in wide-precision planting pattern.(3) Effect of delayed irrigation at jointing stage on winter wheat water use efficiency in wide-precision planting pattern.In the late winter wheat growth stages, delayed irrigation at jointing stage made leaf water use efficiency became the largest one in wide-precision planting pattern. Under the condition of irrigated60.0mm, delayed irrigation at jointing stage significantly increased both yield level water use efficiency and population level water use efficiency in wide-precision planting pattern. It is suggests that delayed irrigation at jointing stage could significantly increase winter wheat water use efficiency in wide-precision planting pattern.Combined with winter wheat grain yield and water use efficiency as a whole, it is suggests that winter wheat in wide-precision planting pattern should be irrigated60.0mm at10days after the jointing stage to achieve reasonable grain yield and water use efficiency in North China.