The effect of soil properties on the transformation of native and added P into different inorganic P fractions was investigated by incubating 28 alkaline/calcareous soils at about 20 per cent soil water content and at 25 ± 2°C temperature for eight weeks. Native Fe-P, Ca-P and Olsen's P increased while saloid-P and Al-P decreased. Transformation of added P into saloid-P decreased logarthmically with increasing CEC, clay, active Fe and organic carbon content. Transformation into Ca-P increased and Fe-P decreased linearly with increasing pH and CaCO3 contents. The recovery of added P as Olsen's P increased by 9.3 per cent with one unit increase in pH, while one per cent increase in organic carbon and clay decreased it by 15.6 and 0.6 per cent, respectively. The available P was significantly and positively correlated with saloid-P but not with Al-P, Fe-P and Ca-P. The contribution of all inorganic P fractions to available P was 86.0 per cent in these soils.
Soil properties, inorganic P fractions, transformation of phosphorus, calcareous soils
