FEDERAL PRISON CAMP AT DULUTH
VERMI-COMPOSTING BIN
OPERATING INSTRUCTIONS
The red wriggler worms in the vermi-composting bin are the species Eisenia fetida. This species is adapted to eating fresh organic material, and thus is ideal for vermi-composting use.
Earthworms are well adapted to the low oxygen levels found under the surface of the ground, (or of the compost, in this case). Fruit flies, whose maggots feed on yeasts which grow on rotting food, are often pests in worm bins. Fruit flies cannot survive the low oxygen levels found a couple of inches under the surface of the vermi-compost: therefore burying food wastes under a minimum two inch deep layer of clean compost will usually prevent or minimize fruit fly infestation.
Since earthworms have no teeth and eat by sucking in their food, they can only eat soft food. Bacteria start breaking the food down, then the worms swallow the softened food.
Heat is released by the bacterial breakdown of food in the bin. This heat can be managed to help keep the bin at a reasonable working temperature. Worms working temperatures range from 45 degrees F to 80 degrees F. At forty degrees F, worms stop moving, and begin to hibernate; and if they freeze, worms die. At temperatures above 80 degrees F, worms start to die. Composting heat can be managed so it helps warm the bins in cold weather. Composting heat needs to be minimized in the summer.
Efficient composting requires nitrogen-rich materials, which are referred to as 'green' materials, and carbon-rich materials, which are referred to as 'brown' materials. The 'green' material in the bin is the food waste. The 'brown' materials in the bin are: the paper towels, dry leaves, and the cotton and strawlike stuff from the mattress recycling.
VERMICOMPOSTING OBJECTIVES:
1) Reduce waste at the Federal Prison Camp, Duluth
a) Lower waste hauling costs
2) Produce high quality organic fertilizer for the greenhouses and garden
a) Lower fertilizer costs
VERMICOMPOSTING MATERIALS
1) Acceptable food wastes:
a) Raw fruit and vegetable wastes (summer and winter)
b) Ground-up (Somat) food (winter only)
2) Unacceptable food wastes:
a) Grain products: bread, pasta, cereals (they grow wild yeasts, which stink)
b) Candy
c) Salty foods, like pickles
d) Heavily preserved foods, like snack cakes
3) Acceptable bedding
a) Brown paper towels
b) Cotton and straw from mattresses
c) Dry leaves
FEEDING PROCEDURES
1)
a) Check food wastes, do not feed large quantities of unsuitable foods (see #2 above)
b) Weigh food, and record weight and type of food
i) The absolutely maximum weight that should be fed per bin section is 200 pounds. 150 pounds or less per section is preferable.
d) Check chart and determine which bins are due to be fed
i) Two consecutive bins are fed at a time. If more than two sections must be fed in one day, two sections should be skipped between the sections being fed: for example, if there was 450 pounds of food waste one day, the food should be evenly distributed between two pairs of sections. Sections #1 and #2 would be fed, #3 and #4 would be left unfed, and #5 and #6 would be fed.
ii) The next feeding would start with sections #9 and #10.
iii) The skipped sections allow the worms to escape excess heat.
2)
a) Push the bedding aside to uncover the surface of the sections to be fed.
b) Dig a cavity for the food, starting several inches in from each of the bin walls, so the layer of food can be as thin as possible.
c) If the food is very wet, put a shredded layer of mattress cotton a couple of inches deep under the food.
3) WINTER FEEDING - HOT FEEDING
a) Mix shredded mattress cotton and straw about half and half in with the food; the extra air makes the compost run hotter.
i) As spring approaches, the weather reports mu êst be watched, so a 'hot' feeding does not heat up the bin right before a heat wave.
b) Dump the food waste into the cavity dug into the compost in the bin.
i) Somat food heats up more than unground food. Somat food and unground food can be mixed together in the winter.
c) Cover the food waste with at least two inches of fiinished compost. This prevents smells from getting out of the bin, and prevents fruit flies from hatching out of the compost.
d) Cover the just-fed sections with six inches of brown paper towels.
e) Replace the black plastic cover on the bin.
4) SUMMER FEEDING -COLD FEEDING
a) Put an inch thick layer of mattress cotton under the food waste
b) Put a one inch layer of unground food (not Somat) over the mattress cotton.
c) Put another one inch layer of mattress cotton over the food.
d) Continue layering the food and the cotton until all the food for the section is fed.
e) Cover the last layer of food with finished compost.
f) Cover the bin section with six inches of paper towels.
g) If the weather gets very hot and the bin is in danger of heating above 80 degrees, water down the bin to cool it down.
5) FEEDING ORDER:
a) Sections: 1& 2; 5 & 6; 9 & 10; 13& 14; 17& 18; 21& 22; 3& 4; 7& 8; 11& 12 etc.
b) Feed two bins, skip two bins, feed the next two... This allows the worms to escape excess composting heat.
HARVESTING COMPOST
1) Finished compost is very dark brown and fine-grained.
2) Worms are found in greater concentrations closer to the surface than farther down.
3) Move the worm-rich compost aside, and harvest the compost underneath. In the spring, it can be brought to the greenhouses and to the garden.
4) Compost can be stored in metal garbage cans if necessary.
WORM JUICE (WASTE LIQUID)
1) Worm juice is stored either in a can in the building, or in a tank outside the building. It is used as liquid fertilizer in a dilution of 20 parts water to one part worm juice.
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