We start this new section with six popular questions
about earthworms and vermicomposting. Visit us again
often as this section will add new questions and answers
periodically.
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here
to read updated questions on Worm Castings
(updated 2-22-06).
1. What is meant by vermiculture, vermicomposting,
and vermistabilization?
"Vermiculture" refers to the science of
breeding and raising earthworms. Such methods provide
a unique opportunity to recover large quantities of
organic wastes, converting them, as in manufacturing,
into valuable products for agriculture, forestry,
horticulture, and pollution management. Though quite
different from conventional thermophilic composting,
these methods are commonly referred to as "vermicomposting."
In vermicomposting, earthworms obtain their nutrition
from the microorganisms thriving on the decaying organic
matter. As the worms multiply, they can consume more
material. Their feeding also increases the surface
area of the material being treated, thus increasing
microbial growth. As this process continues, complex
changes occur and eventually a finely structured material,
known as worm castings or vermicompost, is produced.
Worm castings are suitable as both a plant growth
medium and an agricultural soil amendment.
"Vermistabilization" refers to the use
of earthworms to stabilize (also condition or cure)
organic materials that have been predigested through
aerobic composting or other means. Again, the earthworms
consume microbes and small particles of organic matter
to produce worm castings.
2. So does an earthworm "hear," "see,"
or "smell"?
Yes and no. Like a snake, the earthworm uses its setae
to sense vibrations and "hear." The body
wall contains many nerve receptors that taste chemical
changes (or "smell") and other nerve receptors
that detect light changes (or "see") in
their environment. One interesting fact is, earthworms
can't "see" the color red. (Question and
answer excerpted from The Worm Book.)
3. How much do redworms eat?
The feeding rate, also known as the loading rate,
for vermicomposting systems is governed primarily
by the amount of food that the population of worms
can consume. Composting worms are capable of ingesting
one-fourth to one-half of their body weight in wastes
each day [Haimi and Huhta, 1986]. Other researchers
claim worms can consume one to two times their body
weight per day. The varying rates may be attributable
to variations in temperature, pH, or other environmental
conditions. Experience from existing projects suggests
that for planning purposes, a loading rate of 0.25
to 0.5 lb. (or kg.) feedstock per 1.0 lb. (or kg.)
of worm biomass per day should be adequate for the
low and high feeding potential.
Thus, the estimated total weight of the worm population
in a vermicomposting system will be used to determine
the loading rate. This relationship is often referred
to as worm density (the average weight of worms per
some measure of area or volume). Worm population samples
are used to estimate worm density throughout the entire
system. Because worm populations can grow quite rapidly,
maximum worm densities can be achieved quickly under
optimum conditions.
4. How long will a wooden box last?
Used continuously, without ever letting the box dry
out, unfinished wooden boxes should last about two
to three years. Longevity can be increased by letting
the box dry out for several days between set-ups.
Some people prefer to rotate between two boxes for
more convenient maintenance and to allow the boxes
to dry. A good finish that seals all edges, such as
polyurethane varnish, epoxy, or other waterproofing
material, should extend box-life considerably. (Question
and answer excerpted from Worms Eat My Garbage).
5. How many worms are there in a pound?
That's a bit like asking how many people are there
in a ton? It depends? The size, influenced by age
and diet, of the people or worms determines the number
per ton or pound. Of course, we can talk of averages.
One old, often used rule of thumb is that there are
on average 1,000 redworms of various sizes and ages
in a pound. Our experience is that the average may
vary on either side by the hundreds.
6. How can gardeners increase the population of earthworms
in their soil?
The best way to attract and nourish earthworms is
to feed them lots of organic matter. Peel back a layer
of mulch that has been in place for at least a few
days, and you will see the evidence of their activities--little
piles of castings next to their tunnel entrances-and
the worms themselves, working on your behalf. (Answer
excerpted from Start with the Soil).
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