Introduction Phosphorus (P) is a critical nutrient influencing soil fertility, yet its role in shaping bacterial community structure remains underexplored, particularly in native grasslands versus agricultural systems. This study aimed to evaluate how bioavailable P and other edaphic factors influence soil bacterial communities across contrasting land-use types. Methods Soil bacterial communities were assessed using 16S rRNA gene-based amplicon sequencing at two contrasting sites in northeast Kansas, USA: native tallgrass prairie at Konza Prairie Biological Station (KPBS) and agricultural soils at Hays. In parallel, geochemical profiling was conducted to quantify bioavailable P and other soil physicochemical properties. Results Soil bacterial abundance, diversity, and community composition differed significantly between native grassland and agricultural soils. Bacterial abundance was higher in grassland soils (p 0.05) and positively correlated with soil organic matter (SOM), K + , and Mg 2+ . In contrast, alpha diversity metrics (ASV richness and Faith’s Phylogenetic Diversity) were greater in agricultural soils and negatively correlated with water-extractable soil organic carbon (WE-SOC, p 0.05), suggesting that excess labile carbon may reduce diversity or reflect indirect land-use effects. Beta diversity analyses revealed distinct community composition between sites, primarily structured by WE-SOC (r 2 = 0.41), soil moisture (r 2 = 0.52), and pH (r 2 = 0.43), with a smaller contribution from labile P forms (r 2 = 0.21). Although specific taxa responded to P pools, soil P did not emerge as the dominant driver of overall microbial community structure. Discussion These findings indicate that anthropogenic land-use changes, such as agriculture, influence soil microbial communities primarily through broader physicochemical shifts rather than direct phosphorus enrichment. This highlights the indirect role of P within a complex network of soil properties governing microbial ecology.
Banerjee et al. (Thu,) studied this question.