Crop diversity affects the processes of soil physical structuring and most likely provokes changes in the frequencies of soil microbial communities. The study was conducted for soil prokaryotic diversity sequencing 16S rDNA genes from a 25-year no-tillage experiment comprised of two crop systems: crop succession (Triticum aestivum-Glycine max) and rotation (Vicia sativa-Zea mays-Avena sativa-Glycine max-Triticum aestivum-Glycine max). The hypothesis was that a crop system with higher crop diversification (rotation) would affect the frequencies of prokaryotic taxa against a less diverse crop system (succession) altering the major soil functions guided by bacterial diversity. Soils in both crop systems were dominated by Proteobacteria (31%), Acidobacteria (23%), Actinobacteria (10%), and Gemmatimonadetes (7.2%), among other common copiotrophic soil bacteria. Crop systems did not affect the richness and diversity indexes of soil bacteria and soil archaea. However, the crop rotation system reduced only the frequencies of anaerobic metabolism bacteria Chloroacidobacteria, Holophagae, Spirochaetes, Euryarchaeota, and Crenarchaeota. It can be concluded that crop succession, a system that is poorer in root diversity over time, may have conditioned the soil to lower oxygen diffusion and built up ecological niches that suitable for anaerobic bacteria tolerating lower levels of oxygen. On the other hand, it appeared that crop rotation has restructured the soil over the years while enabling copiotrophic aerobic bacteria to dominate the soil ecosystem. The changes prompted by crop succession have implications for efficient soil organic matter decomposition, reduced greenhouse gas emissions, higher root activity, and overall soil productivity, which compromise to agriculture sustainability.

作物多样性影响土壤物理结构的过程，最有可能引起土壤微生物群落频率的变化。该研究针对土壤原核生物多样性测序 16S rDNA 基因进行了 25 年免耕实验，该实验由两个作物系统组成：作物演替 ( Triticum aestivum - Glycine max ) 和轮作 ( Vicia sativa - Zea mays - Avena sativa - Glycine max -小麦-大豆）。假设是，具有较高作物多样化（轮作）的作物系统会影响原核生物分类群的频率，而相对较少多样化的作物系统（继承）会改变由细菌多样性引导的主要土壤功能。两种作物系统中的土壤均以变形菌（31%）、酸杆菌（23%）、放线菌（10%）和宝石单胞菌（7.2%）以及其他常见的富营养土壤细菌为主。作物系统不影响土壤细菌和土壤古细菌的丰富度和多样性指标。然而，轮作制度仅降低了厌氧代谢细菌绿酸杆菌、全食菌、螺旋体、广古菌和Crenarchaeota的频率。可以得出结论，随着时间的推移，根系多样性较差的作物演替系统可能已经调节了土壤以降低氧气扩散并建立了适合厌氧细菌耐受较低氧气水平的生态位。另一方面，多年来，轮作似乎改变了土壤结构，同时使富养需氧细菌能够主导土壤生态系统。作物演替引发的变化对有效的土壤有机质分解、减少温室气体排放、更高的根系活动和整体土壤生产力具有影响，这会损害农业的可持续性。