Agriculture Reference
In-Depth Information
TABLE 18.3
Optimal Conditions for Breeding
Eisenia
fetida
in Animal and Vegetable Waste
Condition
Requirements
Temperature
15Ï20AC (limits 4Ï30AC)
Moisture content
80Ï90% (limits 60Ï90%)
Oxygen requirement
Aerobicity
Ammonia content of waste
Low <0.5 mg/g
Salt content of waste
Low <0.5%
pH
>5.0 and <9.0
Eisenia fetida
(Savigny) and
Eisenia andrei
, Bouché
The species most commonly used for breaking down organic wastes is
E. fetida
or the very closely
related species
E. andrei.
There are a number of reasons why these species are preferred in
vermicomposting all over the world. They are peregrine species that are very common, and many
organic wastes became colonized naturally by these species. They have a wide temperature tolerance
and can live in organic wastes with a range of moisture contents. They are tough earthworms,
readily handled, and in mixed species cultures they usually becomes dominant, so that even when
vermicomposting systems begin with other species, they often end dominated by
E. fetida
(or
E.
andrei
). Although they are so similar,
E. fetida
and
E. andrei
(the Ñtiger wormÒ and the closely
related Ñred tiger wormÒ) have been distinguished as separate species, but their morphological
characteristics and overall reproductive performances and environmental requirements do not differ
significantly (Reinecke and Viljeon 1990). These two species are widely distributed throughout the
temperate regions of the world and are the species most commonly used in commercial vermiculture
and organic waste reduction systems. Graff (1974), Watanabe and Tsukamoto (1976), Tsukamoto
and Watanabe (1977), Hartenstein (1978), Kaplan et al. (1980), Edwards (1988), and Neuhauser
et al. (1988) all investigated in detail the productivity, growth, and population biology of
E. fetida
when the worms were fed on animal manures, or sewage sludge, so there is much critical information
on the requirements of this species.
In surveys of commercial earthworm farms in the United States and Europe by Edwards (1988)
and in Australia, the earthworms, sold under the name
L. rubellus
,
were all
E. fetida
or
E. andrei.
Data on the biology, ecology, and environmental requirement of
E. fetida
are summarized in the
previous section.
Eudrilus eugeniae
(Kinberg)
This is a large earthworm native to Africa but commonly found in many other countries, including
the United States. It is commonly known as the African night crawler, grows extremely rapidly,
and is quite prolific. It is cultured extensively for fish bait in the United States, and under optimum
conditions it would seem to be an ideal species for earthworm protein production. Its main
disadvantages are its relatively poor temperature tolerance and poor handling capabilities because
it is easily damaged and can be difficult to harvest.
Eudrilus eugeniae
has very high rates of
reproduction (Kale and Bano 1991; Edwards 1988) and is capable of decomposing large quantities
of organic wastes rapidly (Edwards 1988; Neuhauser et al. 1988; Kale and Bano 1991). However,
E. eugeniae
has a preference for higher temperatures and cannot tolerate extended periods below
16AC (Viljoen and Reinecke 1992); it does not survive for long below 10AC. Its use in outdoor
vermiculture may therefore be limited to tropical and subtropical regions, unless lower winter
