Quality Compost Production from Municipality Biowaste in Mix with Rice Straw, Cow Dung, and Earthworm Eisenia fetida

ABSTRACT

The biodegradable portion of city waste is a potential source of plant nutrients, and appropriate techniques of composting can convert it to quality compost with higher nutrient content and lower levels of pathogenic microorganisms. An amount of 68.19 tons of waste is generated in Imphal City, Manipur, India, of which 24.84 tons were biodegradable. Of the total biodegradable municipality waste (MW), 20.7 tons were produced in households and the vegetable markets of the city. The MW were found to contain pathogenic bacteria (PB), namely, Salmonella spp., Shigella spp., Micrococcus spp., and Enterobacter spp. in the range of 6.35–9.28 (log cfu/g dry biomass), and agriculturally beneficial bacteria (BB), namely, phosphate solubilizers, Azospirillum spp., Azotobacter spp., and cellulose degraders in the range of 6.25–8.83 log cfu/g dry biomass. Pre-treatment of the MW by exposure at temperatures of 27°C–50°C in a greenhouse for 5 days could not reduce the level of PB and BB, but by heating at 100°C for 8 h followed by 30°C for 16 h of a day for three consecutive days, the PB (except Micrococcus spp.) could be eliminated. Aerobic composting of the mixture of MW with cow dung (CD) and rice straw (RS) and by inoculation with epigeic earthworm Eisenia fetida, produced high quality manure as evident from more finer particle (56.6%), higher nutrient (2.19% N) content, higher population of BB (7.03–9.19 log cfu/g dry biomass), and reduced level of PB (6.87–8.09 log cfu/g dry biomass).

Acknowledgments

Thanks are due to the Institute of Bioresources and Sustainable Development, Imphal, Manipur, India, for providing space and infrastructure support.

Funding

Thanks to the Department of Science and Technology, Government of India, for financial assistance (Sanction No. SR/WOS-A/LS-55/2008 dated September 22, 2008).