Effects of various straw incorporation strategies on soil phosphorus fractions and transformations

Returning straw to the field is an effective method for optimizing soil phosphorus (P) availability, in which bacteria play important role. However, effects of various incorporation strategies on P transformation between different pools remain unclear. In this study, variations fractions, phosphatase activities and abundance genes (phoD, phoX phoC) as well a P-solubilizing gene (pqqC) at DNA (total) cDNA (transcribed) levels were analysed three treatments, including chopped (StrawD), compost (Compost) straw-derived biochar (Biochar), control (no straw, CK). Compared with CK, moderately labile inorganic (NaOH I-Pi) content significantly decreased non-available (Residual P) increased StrawD treatment. At same time, phosphodiesterase (PD) activity transcribed phoC total pqqC treatment, suggesting that input stimulated transformations from both organic pools. addition, stable Pi II-Pi) Biochar treatment higher than indicating NaOH II-Pi could release available by Pi-solubilizing bacteria. comparison Compost one (resin-Pi) only. its fractions should not be ignored. conclusion, but P, may promote transformation, has latent effect transformation. The study provided comprehensive understanding regulating availability.