Vermicompost is the compost produced by earthworms
through the digestion and discharge of refuse and other
organic wastes. Earthworms (unlike cutworms,
maggots and wireworms) eat dead organic matter. The
ingested organic matter and fine-textured soil excreted
as small granular aggregates provide abundant and
readily available plant nutrients. Live earthworms
aerate the soil and increase the potassium and
phosphorus content in the soil. Earthworms multiply
easily in a moist, warm and well-aerated soil with a pH
between 5.0 and 8.4, containing organic matter with a
low salt and high calcium concentration.
In vermicomposting, the worms used are Lwnbn'cus
rubellus and similar species. Earthworms are
commercially raised (vermiculture) and multiplied in
shallow wooden boxes provided with drainage holes.
Compost pits measuring approximately 3 x 4 x 1 m, are
filled with organic residues, such as straw, animal
manure, green wastes and leaves. Earthworms from a
wooden box are emptied on compost pits, where they
help to decompose the organic residues. When compost
is ready for use, the upper layers of the digested organic
matter (the vermicompost) is collected for use or sale
, and the earthworms are removed to another
pit or to wooden boxes, for the process to continue.
Earthworms can break organic wastes into peat-like
materials rich in nutrients, with good water-holding
capacity and porosity. The maximum waste turnover takes 2 to 4 weeks under controlled conditions of water
and temperature. A ready-to-use vermicompost is
commercially marketed in different sized bags.