Shifts in taxonomic and functional microbial diversity with agriculture: How fragile is the Brazilian Cerrado?

Agricultural practices significantly alter the taxonomic and functional diversity of soil microbes in the Cerrado biome, one of Brazil's most critical grain-producing regions. A study using shotgun metagenomics revealed that conventional tillage (CT) and no-till (NT) systems, introduced 23 years ago for soybean/maize cultivation, reduced macroporosity and microbial biomass while increasing Proteobacteria dominance—particularly Rhizobiales and Bradyrhizobium—likely due to soybean inoculation. In contrast, native Cerrado soils showed higher diversity of Rhizobium, Azospirillum, and other taxa, alongside greater functional diversity. CT systems, despite harboring more taxonomic sequences, exhibited reduced functional profiles, suggesting a potential trade-off in microbial efficiency. The findings underscore the fragility of the Cerrado's soil microbial community beneath its resilient vegetation, highlighting the need for sustainable agricultural practices to preserve biodiversity and ecosystem functions.

Souza, R. C., Mendes, I. C., Reis-Junior, F. B., Carvalho, F. M., Nogueira, M. A., Vasconcelos, A. T. R., Vicente, V. A., & Hungria, M. (2016). Shifts in taxonomic and functional microbial diversity with agriculture: How fragile is the Brazilian Cerrado? BMC Microbiology, 16(1). https://doi.org/10.1186/s12866-016-0657-z