Factors affecting the vermistabilization process: Temperature, moisture content and polyculture

Vermistabilization is the stabilization of organic wastes using earthworms. The worms maintain aerobic conditions in the wastes and accelerate and enhance the biological decomposition of the wastes. This study evaluated several fundamental factors that affect the performance of the process such as temperature, moisture content of the waste material and the combined use of several earthworm species (polyculture). The earthworms Dendrobaena veneta, Eisenia fetida, Eudrilus eugeniae, Perionyx excavatus and Pheretima hawayana were used in one or more of the studies. The best growth and reproduction of these species occurred at temperatures of 20–25°C. Growth of all five species was reduced at 30°C and death occurred at 35°C. Of the five species, E. fetida produced the largest number of young in a 20 week study. The growth of E. fetida occurred optimally in media with a total solids content, wet basis, of between 9–16%. Polyculture did not have any obvious advantages over monoculture.