Vol. 10, Issue 10 (2021)

Author(s):
Khurshid Alam, Mandira Barman, Sarvendra Kumar and Prasenjit Ray

Abstract:
The exploitation of the fixed P pool in soil is an urgent need since rock phosphate supplies, the raw material for phosphatic fertilizer manufacturing, are quickly depleting. Phosphate solubilizing microorganisms (PSMs) are a viable approach for solubilizing this fixed P pool in soil. An incubation study was carried out in the laboratory at ambient temperature to assess the release of P from highly weathered acid soil of Assam (order- Ultisol, pH= 4.23) as influenced by phosphate solubilizing microorganisms (PSMs) by applying pure cultures of either phosphate solubilizing fungi (PSF), Aspergillus niger or phosphate solubilizing bacteria (PSB), Enterobacter sp. to the soil. Although the soil had very low available P content (8.59 kg ha^-1), total P content of the soil was 526 kg ha^-1, indicating a high amount of P might be present in fixed form, which could be solubilized by PSMs. Results indicate that the PSF significantly increased the release of P from soil over control (0.10 to 0.14 mg kg^-1). However, the increase was maximum initially and the magnitude of increase decreased gradually with increasing days of incubation. On the other hand, PSB was ineffective in mediating the release of P from fixed pool in this soil.