Inorganic P fractionation in Shrink-swell soils of Central India: A case study
Inorganic P fractions in shrink-swell soils representing six soil series of Adan river basin, Darwha tehsil, Yavatmal district, Maharashtra were studied to understand the relationship between the P fractions and soil properties. These clayey soils were neutral to strongly alkaline (pH 6.70 – 9.34), calcareous and low to medium in organic carbon. The sequential extraction of inorganic soil P fractions indicated relative abundance as Ca2-P<Fe-P<Al-P<O-P<Ca8-P<Ca10-P. The plant available forms of P (Ca2-P, Al-P and Fe-P) contributed nearly 10 per cent of total inorganic P while the rest was in unavailable forms. The correlation matrix indicated that plant available forms of P had significant negative correlation with soil pH, EC and CaCO3 and significant positive correlation with organic carbon. The P fractions showed significant correlation among each other which implies that available P forms are constantly replenished by other forms of P pools in the soils.