Long-Term Vineyard Cultivation Reshapes Soil Organic Phosphorus Speciation, Phosphatase Activities, and phoC- and phoD-Harboring Bacterial Communities
Organic phosphorus (OP) transformation in perennial vineyards is strongly influenced by long-term cultivation, fertilization, and associated changes in soil properties. However, the relationships among soil OP speciation, phosphatase activities, and phoC- and phoD-harboring bacterial communities remain poorly understood. In this study, soils from 20-year-old vineyards (Y20) and adjacent uncultivated reference sites (CK) in Penglai, China, were compared. Long-term vineyard cultivation significantly increased soil available P (AP), orthophosphate, corrected monoesters (cMonoesters), and specific monoesters (myo-inositol hexakisphosphate (IHP), scyllo-IHP, and choline phosphate). Vineyard cultivation also enhanced acid phosphomonoesterase (ACP) activity while reducing alkaline phosphomonoesterase (ALP) activity. Furthermore, the alpha-diversity of phoC-harboring bacteria declined, whereas the composition of phoD-harboring community shifted significantly. Correlation analyses showed that soil OP forms correlated positively with ACP activity and phoD community composition, but negatively with ALP activity. Overall, vineyard cultivation increased P availability primarily via P redistribution among chemical forms and simultaneously promoted the retention of stable cMonoesters, processes mainly driven by phosphomonoesterase activities and the phoD-harboring bacterial community. These findings highlight the coordinated roles of P speciation, phosphatases, and functional microbiomes in regulating P transformations in perennial vineyard soils.