Solid Waste Management Through Vermi- and Phosphate-Enriched Composting Techniques for Sustainable Agriculture

Abstract

Metropolitan cities of India generated about 64.8 million tonnes (Mt) of city refuse during 2010. This waste material had a potential to prepare 9.1 Mt of compost. The production of municipal solid waste (MSW) is expected to increase to 107 Mt by 2030. Big cities like Delhi, Mumbai and Kolkata with population greater than 10 million are generating 4000–6000 tonnes of MSW daily. Other cities such as Bhopal, Nagpur, Chennai and Bangalore are producing about 1500–3000 tonnes of MSW per day. Although about 41% of these wastes contain biodegradable organic matter, only 8.9 Mt of MSW are composted which accounts for 8.6% of the total MSW. For the efficient recycling of biodegradable organic wastes, composting technologies viz; vermi-composting, phospho-compost, microbial-enriched compost and phospho-sulpho-nitro-compost preparation have been developed, using agro-industrial wastes, MSW and distillery effluents, amended with certain mineral/mining waste materials (rock phosphate, micas and pyrites) for increasing the nutrient supply potential of the composts. Methods have been standardized to decompose city wastes by earthworm alone or P-enriched earthworm compost using rock phosphate. It was observed that the vermi-composting process is faster than conventional composting because the material passes through earthworm gut, whereby the resulting earthworm castings are rich in microbial activity. The present study suggests that the vermi-compost and P-enriched vermi-compost are becoming important alternative to conventional compost and farmyard manure (FYM) sources for organic farming due to shortage in the supply of dung and use of vermi-compost to improve soil physical, chemical and biological conditions, thereby enhancing productivity and sustainability of agriculture.