Effect of Different Nitrogen Fertilizer Synergists,Water and Nitrogen Amount on Winter Wheat Yield

In order to study the effects of different nitrogen fertilizer synergist and water and nitrogen amount on the yield of winter wheat,a field experiment was carried out by using a split zone design. The main area had three water levels（ W1: 30 mm,W2: 60 mm and W3: 90 mm）,and subplot had three nitrogen levels（ N1: 75 kg/hm~2,N2: 150 kg/hm~2 and N3: 225 kg/hm~2）. A non-nitrogen control was set under each main area（ CK）,and deputy vice district was treated with two kinds of nitrogen fertilizer synergists with urease inhibitor（ NBPT） and double inhibitors（ NBPT + DCD）,using traditional fertilization（ CO） as the control. The results showed that the yield of winter wheat was significantly affected by irrigation level,nitrogen application level and type of nitrogen synergist（ P ＜ 0. 01）. The yield of winter wheat under three nitrogen fertilizer synergist was increased at first,and then decreased with the increase of irrigation water/nitrogen application rate. Compared with CO,the yield of NBPT and NBPT + DCD reached the maximum at 60 mm of irrigation and 75 kg/hm~2 of nitrogen,which were20. 23% and 38. 96%,respectively. Regression analysis and frequency analysis showed that NBPT could achieve higher yield of winter wheat in the range of 139 ～ 183 kg/hm~2 nitrogen application and 47 ～67 mm irrigation. The yield reached the theoretical maximum of 7 409 kg/hm~2 when nitrogen application was 162 kg/hm~2 and irrigation was 48 mm. Under the treatment of NBPT + DCD,the yield of winter wheat was higher when nitrogen was applied at 149 ～ 185 kg/hm~2 and irrigation water was 50 ～ 65 mm.Among them,the theoretical maximum yield was 8 329 kg/hm~2 when nitrogen was applied at 158 kg/hm~2 and irrigation water was 51 mm. When the maximum yield was obtained by CO treatment,the nitrogen application interval was 143 ～ 247 kg/hm~2,and the irrigation interval was 49 ～ 63 mm,and the corresponding yield within this interval was 5 912 ～ 6 443 kg/hm~2. It can be seen that both NBPT and NBPT + DCD had obvious effect of increasing yield and saving fertilizer,and NBPT + DCD was better.