Composition:

Viable Cell Count: CFU 1 X 10⁸ per ml min.

Contamination level: No Contamination at 10⁵ dilutions

pH: 5.0 to 7.5

Key Features of PSB (Phosphate Solubilizing Bacteria):

Mechanism of Action:

PSB secrete organic acids (e.g., citric acid, gluconic acid) that lower the soil pH, solubilizing inorganic phosphates like tricalcium phosphate, iron phosphate, and aluminum phosphate.

They produce enzymes such as phosphatases and phytases, which mineralize organic phosphorus compounds into plant-available forms.

Common PSB Species:

Bacterial Genera: Pseudomonas, Bacillus, Rhizobium, Enterobacter, Serratia, Azotobacter, and Burkholderia. These bacteria are often found in the rhizosphere (root zone) of plants, where they interact closely with plant roots.

Benefits of PSB:

• Improved Phosphorus Availability:Reducing the need for chemical phosphate fertilizers
• Sustainable Agriculture: Reduces dependency on synthetic fertilizers, promoting eco-friendly farming practices
• Enhanced Plant Growth: Increase root development, flowering, and crop yield
• Soil Health:Improves soil structure and microbial diversity
• Cost-Effective: Lowers fertilizer costs for farmers

Applications in Agriculture:

Applications of PSB:

Irrigation:1 litre in one acre

Seed Treatment: Seeds are coated with PSB to promote early root colonization (10 ml per Kg seeds)

Composting: PSB are added to compost to improve phosphorus content.

PSB are used as biofertilizers in crops such as cereals, legumes, vegetables, and fruits.

Factors Affecting PSB Efficiency:

Soil pH, temperature, and moisture levels.

Presence of organic matter and other nutrients.

Compatibility with other soil microorganisms and fertilizers.

Phosphate Solubilizing Bacteria are essential for sustainable agriculture, as they improve phosphorus availability, reduce reliance on chemical fertilizers, and enhance soil health. Their use in biofertilizers is a promising approach to address phosphorus deficiency in soils while promoting environmentally friendly farming practices.