~(32)P示踪法研究溶磷真菌对磷肥转化固定和有效性的影响

采用³²P示踪技术,研究了溶磷青霉菌P8对肥料磷与土壤有效磷的转化、固定和有效性的影响.结果表明,溶磷青霉菌菌剂能够增加玉米、花生的生物量,促进作物对土壤和肥料磷素的吸收;溶磷菌剂具有防止有效磷转化为难溶Ca₁₀-P的作用,增加有效态磷(Ca₂-³²P、Ca₈-³²P)的比例.随时间延长,施入的³²P转化为Ca₁₀-P的数量(或比例)逐渐增加,但是相对于未接种菌剂处理,接种青霉菌菌剂的土壤磷和肥料磷转化为Ca₁₀-P比例最低.溶磷青霉菌菌剂不仅能够防止有效磷向难溶磷Ca₁₀-P的转化,而且其效果能够维持较长时间.

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.