Short-term application of organic fertilization impacts phosphatase activity and phosphorus-mineralizing bacterial communities of bulk and rhizosphere soils of maize in acidic soil.

Aims: Organic manure (OM) is an effective amelioration measure for acidic soils. Acid (ACP) and alkaline phosphatases (ALP) encoded by bacterial phoC and phoD genes, respectively, are responsible for organic phosphorus (P) mineralization. However, the short-term influence of OM application on phosphatase activity and organic P-mineralizing bacterial communities of bulk and rhizosphere soils in acidic soils is less known. Methods: Maize was grown in acidic soil (pH 4.40) supplied with 0, 1, 5, 10, 20 and 50 g OM kg− 1 dry soil for six weeks. Maize biomasses and nutrients, soil physicochemical properties and phosphatase activities, and P-mineralizing bacterial communities were observed. Results: Rhizosphere showed higher ACP and ALP activities than bulk soils, and the rhizosphere effects were stronger than OM application. The Shannon index of phoC- and phoD-harboring bacteria responded differently to both rhizosphere effect and OM application, with a stronger influence from maize rhizosphere. The rhizosphere effect significantly affected both phoC- and phoD-harboring bacterial community structures, but OM application only influenced phoD-harboring bacterial community structure. Co-occurrence network of the phoD-harboring bacteria had higher average degree and more nodes and edges than phoC-harboring bacteria. PLS-PM results suggested that the rhizosphere effect exhibited greatest contribution to soil ACP and ALP activities than OM treatment. Conclusion: Compared with short-term OM application, maize rhizosphere effect showed stronger influences on soil phosphatase activities and P-mineralizing bacterial communities in acidic soils. The phoD-harboring bacteria showed the more sensitive response to the rhizosphere effect and OM application, while phoC-harboring bacteria was only influenced by rhizosphere effect. [ABSTRACT FROM AUTHOR]