Agriculture Reference
In-Depth Information
the earthworms digestive system. Few yeasts, protozoa and certain groups
of fungi such as F
usarium oxysporum, Alternaria solani
, and microfungi
were digested by the earthworms,
Drawida calebi, Lumbricus terrestris
and
Eisenia foetida
.
Bacillus cereus
var
mycoides
were reported to de-
crease during gut passage while
Escherichia coli
and
Serratia marcessens
were completely eliminated during passage through earthworm gut (Ed-
wards and Fletcher, 1988).
Earthworms are classifi ed into epigeic, anecic and endogeic species
based on defi nite ecological and trophic functions (Brown 1995; Bhat-
nagar and Palta 1996) (Table 1). Epigeic earthworms are smaller in size,
with uniformly pigmented body, short life cycle, high reproduction rate
and regeneration. They dwell in superfi cial soil surface within litters, feeds
on the surface litter and mineralize them. They are phytophagous and
rarely ingest soil. They contain an active gizzard which aids in rapid con-
version of organic matter into vermicomposts. In addition epigeic earth-
worms are effi cient bio-degraders and nutrient releasers, tolerant to dis-
turbances, aids in litter comminution and early decomposition and hence
can be effi ciently used for vermicomposting. Epigeic earthworms includes
Eisenia foetida, Lumbricus rubellus, L. castaneus, L. festivus, Eiseniella
tetraedra, Bimastus minusculus, B. eiseni, Dendrodrilus rubidus, Dendro-
baena veneta, D. octaedra
. Endogeics earthworms are small to large sized
worms, with weakly pigmented body, life cycle of medium duration, mod-
erately tolerant to disturbance, forms extensive horizontal burrows and
they are geophagous feeding on particulate organic matter and soil. They
bring about pronounced changes in soil physical structure and can effi -
ciently utilize energy from poor soils, hence can be used for soil improve-
ments. Endogeics include
Aporrectodea caliginosa, A. trapezoides, A.
rosea, Millsonia anomala, Octolasion cyaneum, O. lacteum, Pontoscolex
corethrurus, Allolobophora chlorotica
and
Aminthas sp
. They are further
classifi ed into polyhumic endogeic which are small sized, rich soil feed-
ing earthworms, dwelling in top soil (A1); mesohumic endogeic which
are medium sized worms, dwelling in A and B horizon, feeding on bulk
(A1) soil; and oligohumic endogeic which are very large worms, dwell-
ing in B and C horizons, feeding on poor, deep soil. Aneceics are larger,
dorsally pigmented worms, with low reproductive rate, sensitive to dis-
turbance, nocturnal, phytogeophagous, bury the surface litter, forms mid-
