华北平原不同施氮量对玉米产量和品质的影响研究

试验研究了5个供氮水平下不同施氮量对玉米产量和品质的影响。结果表明，不同施氮量对玉米产量和品质有不同的影响。施氮量为337.5 kg/hm²时，玉米产量最高，达到6 845.0 kg/hm²；继续增施氮肥，产量显著降低。施氮量为112.5 kg/hm²和225 kg/hm²时，蛋白质含量最高，达到了8.94%，品质最好；施氮量继续增加，玉米品质显著下降，其绝对值下降了0.13%～0.56%。225 kg/hm²为玉米最佳氮肥用量。为了进一步促进农业可持续发展，在玉米生产中应设定氮肥使用上限，减少氮肥在环境中的残留和积累，减少潜在的农田环境污染，提高氮肥增产效果。

The Effects of Different Nitrogen Applications on Yield and Quality of Maize in North China Plain

The test studied the effects of five different nitrogen applications on yield and quality of maize. The results indicated that different nitrogen-applied would have taken effects on yields and qualities of maize. The yield would improve as while as the increase of nitrogen application. The nitrogen dosage was 337.5 kg/ha, the maize yield would be growing, the harvest would reach the highest 6 845.0 kg/ha. More nitrogen application would be decreased the yields significantly. When the nitrogen application was between 112.5 kg/ha and 225 kg/ha, the protein content was about 8.94%, the quality and the effects would reach the climax. More nitrogen application would also decrease the quality apparently. The absolute rates decreased 0.13% - 0.56%. The experiment showed that the most suitable nitrogen-applied-quantity was 225 kg/ha. In order to promote agricultural development continuously, the max of nitrogen application should be limited in a circumstance, as meanwhile, reducing the environmental pollution and forbidding the potential harms of nitrogen usage.