Forms of Phosphorus in Vidarbha Soils

In a study on forms of phosphorus in some Vidarbha soils it was found that the surface layers of all the profiles were rich in total phosphorus. Inorganic fraction constituted a significantly high proportion of the total. Aluminium occluded phosphorus was found to be in traces. The organic P content was low and generally decreased with depth- Three profiles, containing sufficiently high amounts of free CaCO₃ and total CaO, were rich in Ca-phosphate form. Profiles having less of free CaCO₃ or CaO were rich in iron and aluminium phosphates. The reductant-soluble P was observed to exceed 25 per cent of the total phosphorus. It was found to be related with sesquioxides or iron content. All the soil profiles were poor in available phosphorus. Significant correlations of available P with Ca-P have been observed in soils containing more CaCO₃ and with Fe-and Al-P in other soils.