Agricultural land use modulates responses of soil biota and multifunctionality to increased antibiotic pressures

Antibiotic contamination has been a global agricultural issue due to heavy discharge and undesirable consequences. However, the link between antibiotic pressures and soil multifunctionality in agricultural ecosystems remains unclear. In this study, we investigated the antibiotic levels, soil functions, and their relationships in two land use types (peanut fields vs. maize fields) in a manure-amended agricultural area. The results showed a significant non-linear relationship between antibiotic pressures and soil multifunctionality in agricultural ecosystems. Antibiotics exhibited an inhibitory effect on soil functioning at high concentrations. Specifically, soil bacterial diversity and richness, earthworm abundance, and nitrogen mineralization were significantly suppressed by increasing antibiotic pressures. Increasing antibiotic contamination had peak effects on soil multi- functionality loss at a threshold of 81 %, resulting in a decrease of-1.24 in functions. Land use played a significant role in modulating the effects of antibiotic levels on soil multifunctionality. A significant response of soil function to antibiotics was observed only in peanut fields, not in maize fields. Additionally, differences in antibiotic pressures promoted the functional turnover in agricultural ecosystems. Therefore, controlling antibiotic contamination in soil is crucial for the sustainable provision of soil ecosystem functions, considering the role of land-use modulation in planning and management decisions.