Microbial diversity of soils under different land use and chemical conditions

Soil microbial communities are crucial to ecosystem functionality, influencing soil fertility and health. Microbial diversity in soil is impacted by various land-use practices and environmental conditions, but the effects on both prokaryotic and eukaryotic communities remain insufficiently understood. This study investigates the influence of different land-use types and soil chemical properties on the composition and diversity of prokaryotic and eukaryotic microbes using next-generation sequencing (NGS). Soil samples were collected from seven distinct locations in South Korea, representing various land uses, including paddy fields, upland fields, forest areas, hydrocarbon- and heavy-metal-contaminated sites, greenhouse soils, and reclaimed tidal soils. Alpha diversity, assessed using Chao1 and Shannon indices, and beta diversity, evaluated through Bray-Curtis dissimilarity and Principal Coordinates Analysis (PCoA), were used to characterize microbial diversity. Soil chemical properties were analyzed, and their relationships with microbial community structure were examined. Results revealed significant variations in both prokaryotic and eukaryotic diversities across different land uses. Soils under conventional agricultural management (paddy and upland fields) showed higher microbial diversity compared to soils with high salinity, contamination, or low suitability for agriculture. Prokaryotic communities were dominated by Proteobacteria, Chloroflexi, Acidobacteria, and Bacteroidetes, with variations in abundance linked to soil condition and quality. Eukaryotic communities predominantly consisted of Opisthokonta, SAR (Stramenopiles, Alveolates and Rhizaria), and Amoebozoa, with distinct abundance patterns across different soils. In conclusion, land-use practices and soil chemical properties significantly influence microbial diversity and community composition. Soils subjected to less stress, e.g., agricultural soils, exhibited higher microbial diversity, while stressed soils, e.g., contaminated and saline soils, showed reduced diversity. These findings emphasize the importance of understanding the interplay between land management and microbial ecology for optimizing soil fertility and health.