Decomposition of kitchen waste amended with cow manure using an epigeic species (Eisenia fetida) and an anecic species (Lampito mauritii)

An epigeic (surface dweller) earthworm species Eisenia fetida and an anecic (deep burrower) earthworm species Lampito mauritii have been tested for decomposition of kitchen waste plus cow dung. Chemical analyses of worm-worked substrates by both species showed g/kg increases in nitrogen, phosphorus and potassium and decreases in C/N and C/P ratios after 150 days of vermicomposting. However, organic carbon matter showed reduction in their amounts for 3–4 months and afterwards slightly increased up to 150 days. E. fetida produced 0.27%, 156%, 41% and 38% increases in organic carbon, nitrogen, phosphorus, and potassium as well as 61% and 29% decreases in C/N and C/P ratios as compared to control after 150 days of earthworm inoculation. In contrast, L. mauritii produced 14%, 102%, 33% and 42% increases in organic carbon, nitrogen, phosphorus and potassium as well as 43% and 14% decreases in C/N and C/P ratios as compared to control after 150 days of earthworm activity. There was moderate mineralization and faster decomposition by E. fetida in comparison to moderate mineralization and moderate decomposition by L. mauritii. The average numbers of cocoons and adults produced were greater by E. fetida than by L. mauritii after 150 days. These results indicate E. fetida may be a better adapted species for decomposition of kitchen waste plus cow dung under tropical conditions.