A
living ecosystem of worms, sowbugs and bacteria are invited
to this table. They are a part of the digestive system that
starts with a person discarding food leftovers and shredded
paper into the portal at the top. The bacteria and sowbugs
begin breaking down the waste and the worms soon join in to
further digest it into a rich compost that sprinkles out of
the bottom of the fabric bag that hangs beneath the table.
This compost is used as a fertilizer for plants, such as those
at the base of the table.
The
human plays an important part at the table by eating, feeding
the food waste to the worms, feeding the resulting fertilizer
to the plants, or by simply sitting and appreciating the living
ecosystem she/he is a part of. A cross-section of the activity
inside the top 9 inches of the compost is made visible using
an infrared security camera connected to an LCD screen built
into the table. On the screen, viewers can see the live movements
of the worms and sowbugs inside.
Technical
info
download
my construction diagram. It may not be entirely complete,
but it will give you an idea of how to construct something
like this, if you so desire.
Or,
for some very detailed instructions on
how to make your own basic worm composting bag (without
the table) I've created illustrated instructions in this "Instructable"
Vermicomposting - The hand-made composting
bag is based on a "flow-through" vermicomposting
system, designed to make harvesting the worm castings much
easier. Standard methods involve separating worms by hand,
or by lifting heavy sections of the stacking tray type of bin.
I use several types of bins at home, including the homemade
plastic tub type and the fancy,
stacking tray type, but I am most excited about the ease
of use of this new bag type. To construct my own vermcomposting
bag, I've sewn together 2 layers of landscape fabric, rather
than use plastic, in order to increase the air circulation
around the sides, but the top is closed off, to keep more moisure
up there. The
worms like the moisture level to be around 75 - 85%. To harvest
the "black gold" castings, I simply untie the string
at the bottom of the bag and squeeze it a bit to allow the
finished castings to fall out. Very few worms remain at the
bottom of the bag where the finished castings are, because
the food is at the top of the bag and the material gets a bit
drier at the base, so the worms don't like it. More info on
vermicomposting here.
And a very informative how-to handout, written by Amy Stewart
can be downloaded here.
Seeing
worms - is more difficult than you might imagine,
since worms are harmed by white light. They do not mind infra-red,
but humans cannot see in that frequency. Video cameras are
sensitive to that frequency, but often have filters to remove
it. The video camera used in this project is a very low light,
black and white security camera (.0003
lux, 600 lines of resolution, Sony Super HAD CCD). It
is showing the worms and sowbugs live, using infra-red light
that filters in from the theater gels located beneath the
feeding portal (because it turns out the white polyethylene
lets a little light in) and on the side of the bag
where a clear acrylic dome cuts into the fabric for the camera
to image the action inside the composting material. The filters
that allow only infra-red to pass are Rosco #27 and #382, discussed
in detail here. The camera is connected to a 10" LCD
screen, which was removed from a $200 snail-shaped TV for
kids made by Hannspree.
Wood
and stain - The wood is FSC (Forest
Stewardship Council Certified) oak plywood, which I actually
purchased at Lowes. They have a policy to "agressively
phase out the purchase of wood products from endangered forests".
In an effort to be ecological - and to reference the cycle
of food reprocessing - I decided to stain the wood with a homemade
concoction of boiled red cabbage, mixed with a little
worm compost tea (leachate
from pure worm castings) and alum. This stain is beautifully
purple at first, but after a few days the color fades quite
a lot, even after 2 coats of polyurethane... If anyone knows
of a method to "fix" the color for natural stains,
please contact me at my email below.
Inspirations:
- Dr.
Clive Edwards and Norman
Aroncon, soil ecology researchers at the Ohio State University
who graciously showed me their vermicomposting research and
answered my many questions. Their recent research paper is, Effects
of Vermicompost Tea on Plant Growth and Disease.
- The
Earth Moved: On the Remarkable Achievements of Earthworms - a
book by Amy Stewart.
- N55,
Eco concept art/design collective in Copenhagen, Denmark.
They made a very cool vermiculture project called Soil
Factory.
- MASSIVE
CHANGE, Bruce Mau Design and the Institute Without Boundaries