Plastic film mulching combined with nitrogen application is a prime chief strategy for enhancing maize yields in rain-fed agricultural areas. However, how the practice affects the productivity and functions of soil by altering nitrogen transformation mediated by rhizosphere microorganisms in the Loess Plateau, remains unclear. In this research, an 7-year field location experiment was conducted to ascertain the effects of plastic film mulching with nitrogen application (225 kg N ha−1) on the rhizosphere microbial nitrogen transformation in a rain-fed maize field on the Loess Plateau. Plastic film mulching with nitrogen application reduced the pH value and also increased the abundance of microorganisms (e.g., Nitrosospira, Halomonas) and genes (e.g., pmoB-amoB, hao, nirB, and nirD) during the vegetative stage. This promoted nitrification and dissimilatory nitrate reduction to ammonium, which increased the content of inorganic nitrogen in the rhizosphere. During the reproductive stages, plastic flim mulching reduced the relative abundance of aerobic bacteria (e.g., Skermanella, Sphingomonas), and the ratio of (nirK + nirS) / nosZ, which inhibited denitrification and dinitrogen oxide emission potential. Overall, our findings highlight the feedback mechanism of soil nitrogen transformation to plastic film mulching with nitrogen application in the Loess Plateau, providing valuable insights for manipulating specific microorganisms to regulate nitrogen transformation and promoting the sustainability of soil ecosystems.

中文翻译：

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在黄土高原施用氮气的塑料薄膜覆盖可激活根际微生物硝化和异化硝酸盐还原


在雨养农业地区，塑料薄膜覆盖与施氮相结合是提高玉米产量的主要策略。然而，这种做法如何通过改变黄土高原根际微生物介导的氮转化来影响土壤的生产力和功能，目前尚不清楚。在这项研究中，进行了一项为期 7 年的田间定位实验，以确定施氮 （225 kg N ha-1） 的塑料薄膜覆盖对黄土高原雨养玉米田根际微生物氮转化的影响。施氮地膜覆盖降低了 pH 值，还增加了营养阶段微生物 （例如，亚硝化螺旋藻、卤单胞菌） 和基因 （例如，pmoB-amoB、hao、nirB 和 nirD） 的丰度。这促进了硝化作用和异化硝酸盐还原为铵，从而增加了根际无机氮的含量。在繁殖阶段，塑料薄片覆盖降低了好氧细菌（例如 Skermanella、Sphingomonas）的相对丰度以及 （nirK + nirS） / nosZ 的比率，从而抑制了反硝化和二氮氧化物排放潜力。总体而言，我们的研究结果强调了黄土高原土壤氮素转化为塑料薄膜覆盖施氮的反馈机制，为操纵特定微生物调控氮素转化和促进土壤生态系统的可持续性提供了有价值的见解。