氮肥的过量施用导致显著的氮素损失，降低了环境质量。减少氮肥投入使其与作物需求相匹配对于保持农业生产的可续发展具有至关重要的作用。为了评估不同施氮水平对水稻生产过程中的氮肥利用率和径流负荷的影响，利用长期实验基地开展了相关研究，实验共设置了4个施氮水平，即0、100、200和300 kg/hm²。结果显示，随着施氮量的增加，粮食产量显著提高，而农学效率和偏肥生产力却呈相反趋势。作物地上部氮肥回收率则呈先增加后减少的趋势，并在200 kg/hm²时达到峰值；氮素径流损失随施氮量的增加而增加。

Over-application of N fertilizers resulted in significant N loss and degradation in environmental quality. Reducing N inputs and increasing N use efficiency are crucial for the sustainable development of agricultural production. A long-term field experiment was conducted to investigate the effects of N application rates on N use efficiency by rice plants and N runoff loss. There are four N application rates, i.e. 0, 100, 200, and 300 kg/hm². The results showed that rice yields increased significantly with increasing N inputs, while N use efficiency as agronomic efficiency and partial fertilizer productivity followed the opposite trend. N recovery efficiency increased first and then decreased from 100 kg/hm² to 300 kg/hm² and reached the peak at 200 kg/hm². N losses through runoff increased with increasing N inputs.

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上海市科委基础研究重点项目(12JC1407900)和上海市农委科技兴农推广项目[沪农科推字(2013)第1-1号]资助。