Organic management improves soil P availability via increasing inorganic P solubilization in tea plantations

Abstract

Organic management is a crucial practice for activating residual phosphorus (P) and enhancing its availability in soils, with microorganisms playing a central role in regulating P cycling. Despite this, the effects of long-term organic management on P availability via microbial functional traits remain insufficiently explored. This study evaluates the impact of chemical (industrial fertilizers) (CF) and organic fertilization (OF) over an extended period in tea plantations, also incorporating surrounding forestland (FD) for comparison. We analyzed soil properties, P fractions, microbial functional genes, and microbial communities involved in P cycling. Our findings demonstrated that CF and OF both significantly enhanced soil P availability and nutrient levels, with organic management showing a positive correlation with soil available P. Notably, OF significantly decreased the abundance of pstS, phnC, phnD and phnE compared to CF, suggesting the potentially inhibition of P uptake and transport system. Organic management significantly increased gene abundance of ppk1, ppx, aphA and glpA compared to CF, indicating the promotion of soil inorganic P solubilization and organic P mineralization. Different management did not significantly affected the functional genes relative abundance involved in P starvation response regulation. Organic management also markedly increased the abundance of Actinobacteria, Gemmatimonadetes and Chloroflexi, which were markedly positively related to soil available P. This study advances our understanding of the role of soil microbial functional genes and communities in enhancing P availability, elucidating the impacts of organic resources in subtropical tea plantations.