Vermicompost Potential of Common Earthworms (Eudrilus eugeniae) and Red Wiggler (Eisenia fetida) Worm on the Decomposition of Various Organic Wastes
Zerihun Getachew *
Assosa Agricultural Research Center, Ethiopian Institute of Agriculture Research, Assosa, Ethiopia
Tigist Adisu
Assosa Agricultural Research Center, Ethiopian Institute of Agriculture Research, Assosa, Ethiopia
Lejalem Abeble
Assosa Agricultural Research Center, Ethiopian Institute of Agriculture Research, Assosa, Ethiopia
Bekele Anbessa
Assosa Agricultural Research Center, Ethiopian Institute of Agriculture Research, Assosa, Ethiopia
*Author to whom correspondence should be addressed.
Abstract
Purpose: To evaluate the vermicomposting potential of Eudrilus eugeniae and Eisenia fetida earthworms on decomposition of various organic wastes through worm growth and production of nutrient rich vermicompost.
Methods: Two local Eudrilus eugeniae earthworms (Debrezeit and Keshmando) and commercial Eisenia fetida earthworm were evaluated using different agricultural (maize and haricot bean straws), urban (khat, food and fruits peels) and industrial (bamboo) wastes. Seven types of wastes (each mixed with cow manure) were used and with three earthworm types which gave a total of twenty one treatments. The experiment was laid out in a factorial completely randomised design (CRD).
Results: Earthworm growth and nutrient composition of the final vermicompost was significantly (p <0.05) affected by the main and interaction effects of worm and type of organic feed. High numbers of cocoons and worms, as well as worm biomass, were recorded with Keshmando and Eisenia fetida when fed into khat and maize straw, while the least count and biomass of worms were recorded in an industrial waste feed. The chemical compositions of vermicomposts of all earthworm types produced for each substrate were more than that of their respective initial feed mixture. A significant increase in available plant nutrients and a rapid decomposition of dissolved organic C content were observed in all the vermicompost treatments. The highest % N (0.84) with decreased C: N ratio was found in Debrezeit with khat substrate, while the highest P (370 ppm) and K (12.6 g/kg) contents were found in Eisenia fetida with maize straw.
Conclusion: Results clearly indicated that the type of substrate significantly influenced worm growth and quality of the end product. Worms showed no drastic difference in a decomposition of wastes which exhibited the potential and candidature of local earthworms with Eisenia fetida for vemicomposting. Further, the study revealed the suitability of maize straw for better worm growth and production of nutrient-rich vermicompost
Keywords: Earthworms, vermicompost, substrate, nutrient, organic wastes