Formulating nitrogen-phosphorous-potassium enriched organic manure from solid waste: A novel approach of waste valorization

Abstract

This work investigates the feasibility of utilizing solid wastes viz. wet blue leather, poultry bone and water hyacinth for the production of N-P-K (Nitrogen-Phosphorous-Potassium) enriched organic fertilizers. The nitrogenous component was derived from wet blue leather after exhausting it of Chromium using bi-directional base hydrolysis followed by acid hydrolysis. Upon hydrolysis, a solid collagenic material with significant amount of nitrogen was obtained as a byproduct. Poultry bone was sterilized and then dried at 80°C before crushing to obtain bone meal. Water hyacinth was sun-dried before calcination at 450°C in a muffle furnace to obtain ash. In order to produce N-P-K rich formulation of organic manure, collagen was amalgamated with phosphorus laden poultry bone meal and potassium enriched water hyacinth ash. The efficacy of the resulting organic N-P-K based manure was examined as a nutrient source on Catharanthus roseus (Madagascar Periwinkle). Ammonia analysis for nitrogen content of fertilized soil demonstrated that free nitrogen content in the soil mixed with organic N-P-K formulation was 45.16% and 19.35% higher than natural soil and soil mixed with commercial fertilizer, respectively. Interactive DNA study of organic N-P-K formulation revealed a low intercalation and less interactivity with DNA in nature than commercial fertilizer. Fertilising Catharanthus roseus plant using organic N-P-K fertilizer resulted in significantly higher growth and flowering compared to that observed using commercial fertilizer. Hence the newly developed organic fertilizer could be an efficient and environmentally benign organic nutrient for successful application in the agriculture to enhance the plant growth, over chemical fertilizer.