Growth and Reproduction of Eisenia fetida in Vermicomposting of Organic Fraction of Municipal Solid Wastes

Abstract

The objective of this reseach is to investigate the growth and reproduction of Eisenia fetida during vermicomposting of organic fraction of municipal solid waste (OFMSW). Furthermore the research was intended to assess the applicability of vermicomposting as an alternative recycling process for conversion of OFMSW to a useful stabilized nutrient rich end product. This research was performed in 24 L containes (as experimental units) and in a complete randomized design with five level of substrate mixture consisting of pretreated OFMSW and cow manure (CM) in per cent ratios of: 20:80, 40:60, 60:40, 80:20 and 100:0, respectively, on the basis of total dry matter. The units with 100 % OFMSW were considered as control ones. The experimental period lasted 80 days. The change in number and biomass of adult earthworms, measured at the beginning and at the end of the experimental work was used to evaluate the difference in growth and reproduction of Eisenia fetida under various experimental conditions. Other parameters such as temperature, pH, moisture content and C/N ratio were measured regularly to observe the change in environmental and operational conditions. Statistical assessment of the results was done using SPSS software. The results of the research indicated that a pretreatment step (e.g., under-going conventional composting for a period of 21 days) was required for OFMSW prior to its use as a substrate in vermicomposting process. The results also showed a considerable increase in the number and biomass of E. fetida in all the experimental units. However, the rate of increase varied significantly (p < 0.05) between different units. The growth and reproduction of E. fetida was found to be significantly affected by the proportion of OFMSW in the substrate mixture; increasing as the amount of OFMSW was increased. The best result (211 % increase in number and 468 % increase in weight of the earthworms) occured in the units with only pretreated OFMSW as substrate indicating that, without the need for any additives, the process of vermicomposting can be used as an alternative method in management and recycling of organic fraction of municipal solid waste.