Optimizing N application under straw-covered strip tillage is of great significance to the rational utilization of stover resources as well as ensure food and ecosystem security, and especially NO emissions from agricultural systems. Quantifying NO emissions and even the carbon footprint (CF) from agricultural systems is crucial for future protecting agricultural production systems. A two-year field experiment was conducted on black soil in Northeast China, which set up two tillage systems: strip tillage with straw returning (ST) and conventional tillage (control: CT) without straw and three nitrogen rates: 0, farmers' practice (Nfp 240 kg hm), and optimized nitrogen fertilizer (Nopt 180 kg hm). We examined the characteristics of NO emissions and CF under the ST and CT systems. Among them, we indirectly calculated GHG emissions using the LCA method. Compared with CT, the ST system significantly reduces indirect GHG emissions, but did significantly increase direct cumulative NO emissions by 20.7 %, most likely because the higher soil residual nitrate nitrogen content, WFPS, and soil temperature under ST was 13.0 %, 2 % and 5.7 % higher than that under CT. Nopt treatment markedly reduced cumulative NO emissions by 36.0 %, CF, CF, and CF by 22.4 %, 23.1 %, and 23.5 % in ST, respectively, compared to Nfp. The reduction in energy use of machinery in ST results in lower fuel consumption and thus generating less CF. What's more, the decrease of CF and CF between nitrogen application treatments under ST was 5.2 % and 7.7 % higher than CT, respectively. ST system can effectively achieve higher grain yield and mitigate GHG emissions on black soil in Northeast China compared with CT, but attention should be paid to NO emissions in the soil during the maize growth period. The sustainability of balancing GHG emissions, and economic and environmental benefits can be achieved by optimizing nitrogen fertilizer manage.

中文翻译：

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玉米保守性条耕制度可保持高产并减少温室气体排放，但会增加氧化亚氮排放


优化秸秆覆盖条耕施氮对于合理利用秸秆资源、保障粮食和生态系统安全，特别是农业系统NO排放具有重要意义。量化农业系统的二氧化氮排放甚至碳足迹（CF）对于未来保护农业生产系统至关重要。在东北黑土上进行了两年的田间试验，设置了秸秆还田条带耕作（ST）和不秸秆常规耕作（对照：CT）两种耕作制度，三种施氮量：0，农民实践（Nfp 240 kg hm）和优化氮肥（Nopt 180 kg hm）。我们研究了 ST 和 CT 系统下 NO 排放和 CF 的特征。其中，我们采用LCA方法间接计算温室气​​体排放量。与 CT 相比，ST 系统显着减少了间接温室气体排放，但确实显着增加了直接累积 NO 排放量 20.7%，很可能是因为 ST 下土壤残留硝态氮含量、WFPS 和土壤温度较高，分别为 13.0%、2% 和比 CT 下高 5.7%。与 Nfp 相比，Nopt 处理使 ST 中的累积 NO 排放量显着减少了 36.0%，CF、CF 和 CF 分别减少了 22.4%、23.1% 和 23.5%。 ST 中机械能耗的减少导致燃料消耗降低，从而产生更少的 CF。此外，ST 下施氮处理之间 CF 和 CF 的降低量分别比 CT 下高 5.2% 和 7.7%。与CT相比，ST系统可以有效提高东北地区黑土的粮食产量并减少温室气体排放，但需关注玉米生育期土壤中N2O的排放。 通过优化氮肥管理可以实现平衡温室气体排放以及经济和环境效益的可持续性。