Ingestion of sand and soil by phytophagous earthworm Eudrilus eugeniae: a finding of relevance to earthworm ecology as well as vermitechnology

Epigeic earthworms are phytophagous in habit and are believed to prefer organic matter, principally phytomass, in various degrees of decay. To check whether epigeics will ingest soil/sand even when there is luxury availability of phytomass, the present work was carried out. It was seen that not only soil but even sand particles were ingested by epigeic (Eudrilus eugeniae) tested by us, even as there was availability of phytomass and cow manure in abundance. But the consumption of sand and soil decreased as the days progressed. Moreover, the ingestion of sand and soil with phytomass and cow dung did not show any significant influence on growth and survival of earthworms. It did increase the vermicast mass due to the presence of soil/sand as was confirmed by microphotography using polarizing microscope. The findings have important implications in the design of vermireactors for maximizing their efficiency.