Incubation experiments indoor were conducted to study on effect of
factor of soil constituent on
form transformation of inorganic
phosphates. The results showed that the applied soluble phosphates rapidly transformed into different inorganic forms, the predominant transformed form is Fe P, then the Ca 2 P, Ca 8 P, Al P, and the Ca 10 P and O P were much less than other inorganic phosphates. Soil inorganic phosphates transformation was significantly affected by water content and application of different contents of calcium carbonate, humic acid and straw. Ca 8 P?Al P in light clay soil favorably transformed into Fe P and Ca 10 P under the conditions of low water content (<200g/kg), and high water content(>200g/kg) was disadvantageous to formation of Ca 10 P , however, advantageous to the formation of Fe P. Application of different content of calcium carbonate accelerate the transformation of Fe P?Al P , even Ca 2 P into the forms of Ca 8 P?Ca 10 P. Application of straw and humic acid increased the contents of all inorganic phosphates and total inorganic content, reduced the extent of decreasing of available phosphorus, and raised the level of available P. Al P?Fe P transformed into insoluble calcium phosphate (Ca 8 P,Ca 10 P) with the time prolonging.