Effectiveness of compost inoculated with phosphate solubilizing bacteria

Area of Science:

• Agricultural Microbiology
• Soil Science
• Biotechnology

Background:

• Phosphate is a crucial nutrient for plant growth, often limited by its low solubility in soil.
• Biofertilizers offer a sustainable alternative to chemical fertilizers for improving nutrient availability.
• Fruit waste represents a significant organic resource that can be valorized for biofertilizer production.

Purpose of the Study:

• To design and produce a phosphate-solubilizing bacterial (PSB)-based biofertilizer using locally sourced fruit waste.
• To evaluate the efficacy of PSB inoculation in compost maturation and nutrient content.
• To assess the safety and potential of the developed biofertilizer for soil application.

Main Methods:

• Fruit waste was composted with a 30:1 carbon:nitrogen ratio.
• Compost piles were inoculated with two PSB strains (Pseudomonas aeruginosa CMG4 and AAC1).
• Physicochemical parameters, microbial load, heavy metal concentrations, and seed germination were analyzed after 125 days.

Main Results:

• Compost maturation was achieved with optimal temperature, pH, and moisture content.
• PSB inoculation significantly increased accessible calcium (Ca) content, indicating phosphate solubilization.
• The compost exhibited a high seed germination index (>80%) and safe heavy metal levels, indicating non-toxicity.

Conclusions:

• PSB-inoculated compost effectively solubilizes inorganic calcium-bound phosphate.
• The developed biofertilizer is safe for soil application, with no detrimental heavy metal contamination.
• PSB-rich compost holds significant potential as a sustainable phosphatic biofertilizer to enhance soil fertility.