Soil fertility level is the main modulator of prokaryotic communities in a meta-analysis of 197 soil samples from the Americas and Europe

Soil is one of the most essential life-supporting environments. The processes that define these environments' structures over time and space are still poorly understood. In order to contribute to elucidating the dynamics of microbial communities in soil with different fertility levels, this study analyzes 197 rhizosphere microbiome samples obtained from different soil types, available in six articles. Data from amplicon sequencing analyses were extracted from the articles and 15 main prokaryotic phyla were identified. Soil physical and chemical charac-teristics enabled to classify soils as poor, medium, and rich. The SIMPER test showed that prokaryotic com-munities presented approximately 40 % of dissimilarities when comparing three levels of soil fertility. Proteobacteria, Acidobacteria, and Actinobacteria were the dominant phyla, accounting for 58 % of total OTUs in poor, 54 % in medium, and 47 % in rich soils. However, Verrucomicrobia, Gemmatimonadetes, and Elusi-microbia phyla that seem to present a central importance in the microbial distributions. The relative abundance profile of the main phyla was better separated according to soil fertility level than plant host. Clay, organic matter, pH, K, and P availability show significant linear correlations with some phyla studied. In conclusion, soil physical and chemical characteristics are the main influencers of relative abundance of some prokaryotic phylum. The high diversity of prokaryotic communities present in the plant rhizosphere systems seems to be shifted mainly by soil characteristics.