Coupling Effects of Water-fertilizer on Utilizing of Moisture and Fertilizer under Drip Irrigation

For the purpose of finding an optimized water-fertilizer coupling regime in North China,a field experiment was conducted to study the coupling effects of water-fertilizer on soil water storage,soil nitrogen storage and water use efficiency under drip irrigation,with winter wheat as test crops,following the evaporation of 20 cm pan on the crop canopy.The results indicated that variations of soil water content and yield of winter wheat were mainly affected by irrigation scheduling.In addition,high fertilizer might not produce more nitrogen accumulation in farmland because of the coupling effect of water and fertilizer.Proper ratio of irrigation quota and fertilizer could produce more yield and increase water use efficiency at the same time.In this experimental combination,the yield of winter wheat and water use efficiency reached the maximum level under the coupling combination that irrigation quota was 0.8 Eand the amount of fertilizer was 190kg/hm~2,with lower nitrate leaching potential risksimultaneously.