A reasonable cultivation pattern is beneficial to maintain soil microbial activity and optimize the structure of the soil microbial community. To determine the effect of tobacco−peanut (Nicotiana tabacum−Arachis hypogaea) relay intercropping on the microbial community structure in soil, we compared the effects of relay intercropping and continuous cropping on the soil bacteria community structure. We collected soil samples from three different cropping patterns and analyzed microbial community structure and diversity using high-throughput sequencing technology. The number of operational taxonomic units (OTU) for bacterial species in the soil was maximal under continuous peanut cropping. At the phylum level, the main bacteria identified in soil were Proteobacteria, Actinobacteria, and Acidobacteria, which accounted for approximately 70% of the total. The proportions of Actinobacteria and Firmicutes increased, whereas the proportion of Proteobacteria decreased in soil with tobacco–peanut relay intercropping. Moreover, the proportions of Firmicutes and Proteobacteria among the soil bacteria further shifted over time with tobacco–peanut relay intercropping. At the genus level, the proportions of Bacillus and Lactococcus increased in soil with tobacco–peanut relay intercropping. The community structure of soil bacteria differed considerably with tobacco–peanut relay intercropping from that detected under peanut continuous cropping, and the proportions of beneficial bacteria (the phyla Actinobacteria and Firmicutes, and the genera Bacillus and Lactococcus) increased while the proportion of potentially pathogenic bacteria (the genera Variibacter and Burkholderia) decreased. These results provide a basis for adopting tobacco–peanut relay intercropping to improve soil ecology and microorganisms, while making better use of limited cultivable land.

中文翻译：

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烟花生间作对土壤细菌群落结构的影响

合理的栽培方式有利于维持土壤微生物活性，优化土壤微生物群落结构。为了确定烟草-花生（Nicotiana tabacum-Arachis hypogaea）间作对土壤微生物群落结构的影响，我们比较了间作和连作对土壤细菌群落结构的影响。我们从三种不同的种植方式中收集了土壤样品，并使用高通量测序技术分析了微生物群落结构和多样性。在连续种植花生的情况下，土壤中细菌种类的操作分类单位（OTU）数量最大。在门廊级别，土壤中鉴定出的主要细菌是变形杆菌，放线菌和酸性菌，约占总数的70％。烟花生间作的土壤中放线菌和硬菌的比例增加，而变形杆菌的比例降低。此外，随着时间的流逝，烟花生间作间质中，菌类和变形杆菌的比例进一步发生了变化。在属水平上，烟豆间作在土壤中增加了芽孢杆菌和乳球菌的比例。烟草花生连作间作的土壤细菌群落结构与花生连作中发现的显着不同，有益菌的比例也有所不同（门放线菌和硬毛菌，芽孢杆菌属和乳球菌属增加，而潜在致病菌（瓦氏杆菌属和伯克霍尔德氏菌属）的比例下降。这些结果为在更好地利用有限的耕地条件下采用烟花生间作技术改善土壤生态和微生物提供了基础。