Dissolution of low grade udaipur rock phosphate in a red noncalcareous soil (Typic Haplustalf)

Abstract

The dissolution of low grade Udaipur rock phosphate (URP) in red non-calcareous soil (Typic Haplustalf) was examined through a closed incubation experiment. The rock phosphate (60 and 100 mesh size) at a rate equivalent to 0, 1000, 5000 and 10000 mg P,O5 kg'1 soil was mixed with soil (lOOg) and incubated for 120 days in plastic cups both in the presence and absence of Phosphobacteria. The dissolution was measured through a sequential P fractionation procedure. The per cent dissolution was calculated based on increase in the NaOH extractable P (inorganic plus organic P) as well as decrease in HC1-P (apatite or acid soluble P). Application of Phosphobacteria along with RP resulted in higher dissolution in 60 and 100 mesh size of RP.