Many studies, mostly in temperate regions of the northern hemisphere, have demonstrated that agricultural
practices affect the composition and diversity of soil microbial communities. However, very little is
known about the impact of agriculture on the microbial communities in other regions of the world, most
particularly on the African continent. In this study, we used MiSeq amplicon sequencing of bacterial 16S
rRNA genes and fungal ITS regions to characterise microbial communities in agricultural and natural
grassland soils located in the Mpumalanga Province of South Africa. Nine soil chemical parameters were
also measured to evaluate the effects of edaphic factors on microbial community diversity. Bacterial and
fungal communities were significantly richer and more diverse in natural grassland than in agricultural
soils. Microbial taxonomic composition was also significantly different between the two habitat types.
The phylum Acidobacteria was significantly more abundant in natural grassland than in agricultural soils,
while Actinobacteria and the family Nectriaceae showed the opposite pattern. Soil pH and phosphorus
significantly influenced bacterial communities, whereas phosphorus and calcium influenced fungal
communities. These findings may be interpreted as a negative impact of land-use change on soil
microbial diversity and composition.
• This report is the first of the effect of land-use changes on the diversity of the soil microbial communities
in African grassland soils.
• Land-use changes influence the diversity and structure of soil microbial communities in the Grassland
Biome of South Africa.
• This study serves as a baseline for future studies on South African soil microbial diversity.