Improving resource use efficiency through optimized nitrogen (N) management is the key to increasing crop productivity, but it remains unclear whether integrated N management practices could better improve wheat yield and the use of N and water. Here we investigated the effects of individual and integrated N management practices on wheat production in different soil-climatic conditions, and constructed the relationship between the soil-climate factors and N application rate on wheat yield. Results showed that individual N management practice (optimized N application rate only) reduced wheat yield by 2.4 %, increased N use efficiency (NUE) by 45 %, and decreased water use efficiency (WUE) by 2.2 %; however, integrated N management practice (integrating optimized N rate with irrigation, tillage, manure, or straw return) increased yield and NUE on average by 5.4 % and 55 % respectively, without reducing WUE. In different soil-climate conditions, individual N management practice decreased wheat yield from 1.1 % to 5.0 %; however, integrated N management practice increased yield by 8.5 %, 6.4 %, and 5.8 % in soil organic carbon (SOC) ≥ 10 g kg, mean annual precipitation ≤ 400 mm, and 10 °C < mean annual temperature ≤ 15 °C, respectively. Mixed-effects model showed that the integrated N management practice had a higher yield by better exploiting the yield-enhancing benefits of SOC. Facing the complex production environment of the future, applying integrated N management practice will be a key alternative for improving grain production and resource use efficiency.

中文翻译：

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氮肥综合管理提高小麦产量和水氮肥利用效率


通过优化氮（N）管理提高资源利用效率是提高作物生产力的关键，但目前尚不清楚综合氮管理实践是否可以更好地提高小麦产量以及氮和水的利用。在这里，我们研究了不同土壤气候条件下单独和综合施氮管理措施对小麦生产的影响，并构建了土壤气候因素和施氮量对小麦产量之间的关系。结果表明，单独的氮肥管理实践（仅优化施氮量）使小麦产量降低了 2.4%，氮肥利用效率 (NUE) 提高了 45%，水分利用效率 (WUE) 降低了 2.2%；然而，综合施氮管理实践（将优化的施氮量与灌溉、耕作、粪肥或秸秆还田相结合）使产量和氮肥平均分别提高了 5.4% 和 55%，而没有降低 WUE。在不同的土壤气候条件下，单独的施氮管理措施使小麦产量下降1.1%至5.0%；然而，在土壤有机碳 (SOC) ≥ 10 g kg、年平均降水量 ≤ 400 mm、年平均气温 10 °C < ≤ 15 °C 时，综合施氮管理实践使产量提高了 8.5 %、6.4 % 和 5.8 % ， 分别。混合效应模型表明，综合氮肥管理实践通过更好地利用 SOC 的增产效益而获得了更高的产量。面对未来复杂的生产环境，氮素综合管理实践将是提高粮食产量和资源利用效率的关键选择。