Vermicomposting or worm composting is one of the fastest natural and organic ways of getting manure from waste. This way of composting is also easy and scalable for small or big gardens. It is no wonder that this is very popular in urban areas.
Vermicomposting duplicates the natural way in which organic waste is degraded by worms, bacteria, and fungi, except that it is faster. The vermicomposting system is built so that the conditions and the number of worms are optimum, so the waste breaks down quickly. The manure used is the worms-castings excreted by the worms, which are rich in nutrients like nitrogen, phosphorus, potassium, and many micronutrients. These are precisely the elements lacking in most garden soils!
Building a Vermicomposting System
Setting up the system for worm composting requires few materials and some extra preparation, but you are rewarded by manure that is ready in a short time, in just two to three months. The materials needed are bins, screening material, paper scrap, water, worms, and waste which will act as the food for the worms.
The bins can be made of wood, plastic or glass. Get two five to ten-gallon containers, so that they can be stacked one on top of the other. The bottom bin is to collect the liquid leachates rich in minerals that can be used as liquid manure for pots, even indoors!
The top container should not be more than 15 inches deep, as the worms like to live in the top six inches of the soil. Drill two holes one inch wide at the top for aeration and four to five holes 1/8-inch wide in the bottom to drain out fluids. These holes can be covered by screening material to prevent worms from moving out of the top composting bin down to the bottom bin.
The vermicomposting worms needed are not the earthworms usually found in a garden since these do not feed on the pure organic material. What is needed are manure worms. There are two types, and any one of them can be used. They are the Red wigglers (Eisensia out) and Red Worm (Lumbricus rebellus). Usually, about a pound of worms is used to start, as they will soon multiply.
Building the system
The system has to be built to provide the best conditions for worm composting to occur. For this, the worms need air, bedding, moisture, warmth, and food.
- Air: The holes drilled near the top provide air for the worms
- Bedding: Cut newspapers in strips to provide bedding three inches deep. Add the paper mixed with a pound of soil and compost in the top bin. Even compost from a normal backyard variety will have the necessary microbes and fungi to kick-start the decomposition process and help the worms
- Moisture: To provide moisture, moisten the bedding with some water. The paper should be only moist and not soggy. The bedding should be three inches after it is damp
- Temperature: The ideal temperatures the worms like are 55 to 77˚F. So in places with cold winters the bins have to be brought indoors
Once the bedding is in place, scoop out a hole in the center, and add the worms in and cover them with some bedding. Close the system and let them settle in their new home. Start adding the food after a day.
The materials that can be used as food for the worms are kitchen and garden waste. Avoid greasy food, dairy products, meat, and bones, as these are not easy for the worms to eat. Waste which is uneaten by the worms will rot, and produce a stink. In the case of garden waste, the worms cannot degrade woody substances, so it is only grass clippings and old leaves which can be used in vermicomposting.
Collect kitchen scraps or garden waste for a week, and add the food in, only once a week, as the worms work best when left alone. There is no need to stir or mix the material in the bin. Keep the top bin covered with a loose fitting lid at all times.
Paper with chemical paint, plastic, and fabrics should not be added. The chemical paint could be harmful to the worms, and they don’t feed on plastic and fabrics.
When the bin is nearly full, stop adding any new food. After about three months there will be little or no bedding left, and the bin is filled with compost. The bin is then ready to be harvested.
Stop adding new food to the bin at least two weeks before harvesting. Before shoveling out the compost and adding it to the garden, one more step is necessary- removing the worms from the compost.
One way is to tip the compost on a plastic sheet and to pick the worms with the hands out of the compost. The other method requires more time, but less effort.
In the second method, pile all the compost on one side of the bin, and add new bedding and food on the other side. Leave the bins alone for two weeks. During this time the vermicomposting worms will leave the ready compost pile and move to their new food source. Now remove the vermicompost and use it in the garden. The new bedding filled with worms can be used to start the next batch of compost.
Pros and Cons
There are more pros than cons to using vermicomposting to treat organic wastes. They are:
Quick: Composting with worms gives manure ready for use within 2 to 3 months, whereas other composting methods require 6 to 9 months.
Place: Vermicomposting is possible both indoor as well as outdoors. In fact, the composting bins can be placed under the kitchen sink. This is one of the biggest advantages over other composting methods. Just take care that the organic matter is cut in small bits so that the worms can eat them quickly and no odor is produced.
Extra Worms: At the end of the composting cycle, there are more worms than at the start as they reproduce and double their populations once in 90 days. The extra worms can be added directly in the garden to enrich the soil or can be used as animal feed.
E coli count: Vermicompost kept for 21 days will bring down the number of E coli bacteria to permissible levels according to recent research.
Decentralized: Since this can be easily adopted in homes rural or urban, transportation of organic waste to centralized places can be avoided. This saves fuel used for transportation,
bringing down costs for the community, and reducing CO2 emissions.
Pathogens: Pathogens are not killed in vermicomposting as quickly as in normal compost as there is no build-up of heat. Keeping the compost for 21 days longer will take care of this problem.
Capital costs: The initial cost of setting up a vermicomposting system can be high since the bins – and sometimes the worms – have to be purchased.
Fruit flies: The bins filled with organic matter can attract fruit flies. However, this can be avoided by adding food in quantities that the worms can eat, and by covering the top with soil.
A Win-Win Solution
Vermicomposting is a win-win situation, for producing manure anywhere. The few disadvantages it has can be prevented with proper maintenance and care of the systems.