52 страниц. 2014 год. LAP Lambert Academic Publishing Soil samples were drawn from various Darjeeling orange orchards to study their different physio-chemical properties and their microbial count per gram dry weight of soil. Subsequently, the phosphate solubilizing bacterial (PSB) count in Pikovskaya medium was also counted. Sampling was done from conventionally maintained orange orchards in Posseur and Chibbo busty of Darjeeling district of West Bengal and an organically maintained orange orchard in Baramangwa busty. Soils taken from Posseur and Chibbo busty did not show any phosphate solubilizing activity but the soil samples of Baramangwa busty showed a total phosphate solubilizing bacterial count of 1.01x10^8. From this total count five phosphate solubilizing bacteria i.e. V1, V2, V3, V4 and V5 were found to solubilize the phosphate in the Pikovskaya medium and form a clear halo.