Inositol phosphates in some Australian soils

A study was made of the total amount of inositol penta- plus hexaphosphate in a range of Australian soils. The amounts varied widely, ranging from 1.0 to 356 p.p.m. P, and accounted for 0.4-38% of the total organic phosphorus, with an average value of 16%. Neither the absolute content of inositol phosphate nor its proportion to the total organic phosphorus could be closely associated with any particular soil property. In undisturbed soil profiles the inositol phosphates tended to be concentrated near the soil surface. Inositol phosphates were shown to accumulate in soils when organic matter accumulated under leguminous pasture and to decrease when organic matter was lost from soils as a result of cultivation. The relative decrease of inositol phosphates in the cultivated soils was much smaller than that of the organic phosphorus as a whole.