Zero-Waste Transformation of Plaster of Paris Waste and Microbial Potassium Solubilization for Sustainable Agriculture
Dr Gayathri Dornipati , K. Suchitha Reddy, Department of Biotechnology, Ideal Degree College For Women, Dilsukhnagar., Affliated to Osmania University.
drgayathri79in@gmail.com, principal@idealedu.in


Abstract
The increasing demand for sustainable agriculture and environmentally safe waste management necessitates the development of integrated eco-friendly technologies. This study presents a combined approach involving the green conversion of Plaster of Paris (POP) waste and the development of a microbial biofertilizer using potassium-solubilizing bacteria (KSB) for agricultural applications. POP waste collected from multiple sources was subjected to physicochemical characterization to assess composition and potential contaminants. A novel low-energy green conversion process was developed to transform POP waste into calcium-based soil conditioners and nutrient-enriched by-products, minimizing waste generation and eliminating the use of hazardous chemicals. The converted materials were evaluated for their ability to improve soil pH, structure, water retention, and nutrient availability, resulting in enhanced plant growth performance.
Simultaneously, KSB were isolated from rhizospheric soil using the serial dilution technique on Aleksandrov medium. Morphological and biochemical characterization, including Gram staining, IMViC tests, catalase activity, and starch hydrolysis, revealed metabolically diverse isolates. Functional screening demonstrated significant potassium and phosphorus solubilization and siderophore production, indicating strong plant growth-promoting potential. The most efficient isolates were selected based on solubilization indices and further utilized for mass multiplication and biofertilizer formulation using cost-effective substrates.
The integrated application of POP-derived soil conditioners and KSB-based biofertilizer exhibited synergistic effects on nutrient availability, root development, and plant vigor. This study demonstrates a sustainable, zero-waste strategy that converts hazardous POP waste into valuable agricultural inputs while promoting microbial nutrient mobilization, supporting circular economy principles and sustainable agricultural practices.

Keywords
Plaster of Paris waste; Green conversion; Potassium-solubilizing bacteria; Biofertilizer; Soil conditioner; Sustainable agriculture; Circular economy