[Effects of phosphate-dissolving fungi on transformation, fixation and efficiency of fertilizer 32P].

By using a radioactive 32P-labeled technique, this paper studied the effects of P-dissolving Penicillium oxalicum P8 inoculum on the transformation, fixation and efficiency of fertilizer P. The results showed that the inoculum could prevent available P from fixation by soil, and promoted the uptake of applied P by maize and peanut. Additionally, it reduced the amount of Ca10-P fraction derived from available P, increased the pool of available P, and maintained more 32P in forms of Ca2-P and Ca8-P. With time extending, the ratio of Ca10-P fraction in soil was gradually increased, and the treatment with P. oxalicum P8 showed the lowest ratio of Ca10-P form, compared with treatment without P. oxalicum P8. The inoculum not only prevented available 32P from turning into Ca10-P form, but also had a longer effective period.