Relationship of physicochemical properties of rhizosphere soils with native population of mineral phosphate solubilizing fungi.

Phosphate solubilizing fungi (PSF) were enumerated in 78 rhizosphere soil samples collected from various sites of Bhavnagar district with agro climatic zone of hot, semi-arid region of Gujarat. 81% of samples were inhabited with indigenous PSF; the count varied ranging from 0.01 to 90 × 10(3) PSF g(-1). PSF population in the rhizosphere soils were maximal at pH 7.4-8.4, electrical conductivity (EC) 1.2 dS m(-1) wherein PSF population decreased with a rise in EC. Optimal moisture content ranged ≤10-30% where the abundance of PSF always decreased with increase in moisture levels while suitable organic matter content ranged from ≤0.5-4.5%. Available P range 100-300 mg kg(-1) was the most suitable for occurrence of PSF as being noticed from number of soil samples harboring them in rhizosphere soils. Amongst the various rhizosphere soil properties studied, a highly signifi cant positive correlation was established between PSF and soil available P as well as pH. A signifi cant positive association observed between total fungal population and organic matter as well as soil available P. Both abundance and number of PSF were more pronounced in descending order in plant covers: oilseeds, flowers, orchards, vegetables, pulses and cereals.