Effects of Nitrogen Dressing Rate on the Yield and Grain Protein Content of Winter Wheat under Drip Irrigation

【 Objective 】 To reveal the regulation effects of nitrogen application on yield, protein content and its components of winter wheat under drip irrigation.【 Method 】Using Xindong 18 as the test material, influences of top dressed nitrogen by five methods on nitrogen content of grain, protein content and its component and yield of winter wheat under drip irrigation were studied in the conditions of nitrogen application rate of 300 kg/hm².【 Result 】The results showed that, with no nitrogen application at the setting stage, the yield and quality of grain were all decreased under the circumstance of heavy nitrogen application at the booting stage (F1 treatment) or flowering (F2 treatment) once, or equipartition of nitrogen at booting and flowering (F4 treatment). Although the yield and quality of winter wheat under the whole course fertilization, by reducing the nitrogen application at the jointing stage (F5 treatment) was superior to that of the above-mentioned fertilization methods, it still inferior to the treatment which with heavy nitrogen application at jointing while no fertilization at booting (F5 treatment). Besides, the yield, nitrogen content and protein content of grain and globulin all presented a trend of F3>F5>F4>F2>F1, with the highest yield of 7,820.10 kg/hm², F3 treatment was higher 14.94%, 12.92%, 7.84% and 5.23% than treatments F1, F2, F4 and F5. Both the value of glutenin /prolamin and albumin were also highest at F3 treatment, the grain alcohol ratio was 1.70, which was significantly higher than other treatments. Although there was no significant difference in albumin compared with F5 and F4, but it was significantly higher than F1 and F2 treatment.【 Conclusion 】ll indexes comprehensively considered, it is suggested that the topdressing period and amount of nitrogen should be 41.1 kg/hm² at the setting stage, 123.3 kg/hm² at the jointing stage and 41.1 kg/hm² at the anthesis stage of drip irrigation winter wheat that had similar circumstance with our experimental plot.