The nexus among biosolids land application, PFAS soil accumulation, and plant uptake from a comprehensive soil health perspective.

Biosolids land application is a widespread practice for the beneficial recycling of plant nutrients, yet its full implications at the soil-plant-contaminant nexus remain a challenge. This research aimed to connect soil health conditions using the Soil Management Assessment Framework (SMAF) within biosolids application sites that contained per- and polyfluoroalkyl substances (PFAS) in a shortgrass steppe ecosystem. Evaluation of biosolids rates (0, 5, 10, and 15 Mg ha-1) revealed that increasing biosolids application rates drive the soil accumulation of long-chain PFAS. A distinct distribution difference was observed between soil and plant matrices; while soil profiles were dominated by long-chain PFAS, above-ground plant tissues preferentially accumulated short-chain PFAS (bioaccumulation factor [BAF] ranged from 1.17 to 139.8). Specifically, short-chain perfluorosulfonic acids (PFSAs) accumulated in the plant tissues, despite being nearly undetectable in the soil matrix, demonstrating the high mobility of short-chain PFAS. Multivariate analysis revealed that increasing biosolids-applied soil PFAS concentrations were negatively correlated with soil health conditions and were correlated with suppressed soil biological properties (beta-glucosidase activity, Pearson r = -0.51, and microbial biomass carbon, Pearson r = -0.48). These findings underscore integrating biological soil health monitoring into PFAS assessments of biosolids-amended (agro)ecosystems and further investigating specific PFAS and soil microbial interactions.