Crop straw incorporation alleviates overall fertilizer-N losses and mitigates N2O emissions per unit applied N from intensively farmed soils: An in situ N-15 tracing study

文献类型： 外文期刊

第一作者： Xu, Cong

作者： Xu, Cong;Xu, Cong;Xiao, Guangmin;Ni, Bang;Xu, Xiuchun;Meng, Fanqiao;Han, Xiao;Zhuge, Yuping

作者机构：

关键词： Nitrous oxide; N-15 tracing; Straw incorporation; Nitrogen fertilization; Nitrogen loss; Intensive farming

期刊名称：SCIENCE OF THE TOTAL ENVIRONMENT （ 影响因子：7.963； 五年影响因子：7.842 ）

ISSN： 0048-9697

年卷期： 2021 年 764 卷

页码：

收录情况： SCI

摘要： A thorough elucidation of the coupled effects of N fertilization and straw incorporation on N2O emissions and N losses is crucial for alleviating negative environmental impacts in intensively farmed regions. Here, we conducted an in situ N-15 tracing experiment to assess the source of N2O emissions and fate of fertilizer-N in soil intensively farmed with summer maize (Zea mays L.). Four treatments, i.e., no N fertilization and no straw incorporation (N0S0), straw incorporation only (N0S1), N fertilization only (N1S0), and N fertilization plus straw incorporation (N1S1), were established in the study. Compared with straw removal, straw incorporation increased the seasonal N2O emissions by 22.3% but reduced the N2O emissions per unit of applied N by 6.22% (P > 0.05). The emission of fertilizer-derived N2O occurred mainly in the 13-17 days after fertilization; thereafter, the ratio of fertilizer-derived N2O fluxes would be less than 5%. N fertilization significantly stimulated non-fertilizer-derived N2O emissions and soil CO2 fluxes, especially when straw was incorporated (P < 0.05), indicating that N fertilization might have triggered the mineralization of straw-N and/or native soil organic N. The soil NO3--N concentration in straw-incorporated plots tended to be lower than that in straw-removed plots, especially after N fertilization events. Straw incorporation sequestered 52.5% (27.4 kg N ha(-1)) more fertilizer-N in 1 m of soil than straw removal (P < 0.05) while significantly increasing the fertilizer-N harvest index and maintaining grain yield. Overall, compared with straw removal, straw incorporation significantly reduced total fertilizer-N losses (by 12.8%, i.e., 14.58 kg N ha(-1); P < 0.05). Our study highlights the benefits of straw incorporation for increasing in-season and multiseason fertilizer-N use efficiencies and alleviating fertilizer-N-induced environmental costs in intensively farmed regions. (C) 2020 Elsevier B.V. All rights reserved.

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