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Vermi-composting uses earthworms to produce compost from organic residues. Earthworms can practically eat all kinds of organic matter. The following are the guidelines for preparing a good quality Vermi-compost. |
Promotes faster growth of plants, increase crop yield.
Produces crops with a better taste, and lasting quality, without toxic residues.
Earthworms produce no toxins & carry no diseases.
Earthworms help neutralize soil acidity and reduce waste volume by up to 50%.
Increase crop yield with less irrigation.
Improves groundwater recharge & reduces depletion of groundwater.
Reduces soil salinization and soil erosion.
Lessens pollution, as chemicals are not used.
Increases export of agricultural products with lower pesticide residues.
Lessens wasteland formation.
Lowers risk of crop loss due to pest attack.
Vermi composting waste produces no pollution or unusable residue.
The Vermi composting process involves four general phases:
Collection and preparation of materials
Anaerobic (without oxygen) decomposition
There are four factors, to start Vermi composting, need to consider:
SITE SELECTION
A suitable site for Vermi composting should have adequate water supply and good drainage. It should also be close to the source of materials and must be well shaded.
Collection and preparation of materials
Anaerobic (without oxygen) decomposition
There are four factors, to start Vermi composting, need to consider:
SITE SELECTION
A suitable site for Vermi composting should have adequate water supply and good drainage. It should also be close to the source of materials and must be well shaded.
The earthworm preferred is the African night crawler. They can breed as often as once a week, producing an egg capsule that contains 1-3 young that mature in less than 30 days from hatching. These worms are not harmful to man or domestic animals. They are cold-blooded, breathe through their skin and have a nocturnal habit (tend to shy away from light). These worms can live up to two years and grow up to 30 centimeters (1 foot). They thrive best at temperatures of 24-28°C, with moisture content of 60-80 percent.
Materials used in Vermi composting are kitchen wastes (not including oil, meat and dairy products), garden wastes such as grass clippings and leaves and animal wastes. These compostable materials can be degrading more quickly if they have small particle size to increase the surface area for microbial action. Thus, shredding and pulverizing bulky materials is helpful. In preparing the materials or substrate, it is important to remember that, the proper proportion of cellulosic (high carbon) and nitrogenous (high nitrogen) components must be maintain for rapid composting. The desirable carbon-to-nitrogen range is 25-35:1.These materials then mixed thoroughly. Water added to obtain moisture content of at least 80 percent.
For Vermi composting done inside a limited space, the substrate can be placed in containers such as wooden boxes, plastic bins and old drums. The height of the containers or bins should not exceed 30 centimeters (12 inches).The length and width of the bin will depend on whether it is to be stationary or portable. It also depends on the amount of organic waste to be compost per week. It is advisable to provide 0.2 square meter of surface area per kilogram of waste in the bin.
For Vermi composting units located outdoors like on the farm or in the backyard, the substrate can be heaped in beds or windrows, which may be lined at the sides with bamboo walling or other forms of retaining devices such as screens and blocks. Beds can be stacked at a maximum height of 60 cm (2 feet) for aeration by earthworms.
The next step is the anaerobic stage wherein the bed covered with a plastic sheet to step up the natural decomposition initiated by anaerobic bacteria. The temperature of the substrate in this stage can reach 50-70° Celsius. "The higher the temperature, the faster the decomposition would take place."
This phase may last for one to two weeks. When the temperature of the substrate goes down to ambient condition (24-28° Celsius), the plastic cover of the Vermi composting unit is removed. Aerobic decomposition proceeds by stocking live earthworms into the substrate at the rate of one kilogram of worms per 20-30 kilograms of substrate (dry weight).
The Vermi composting units should be water when necessary to maintain the optimum moisture content of 60-80 percent (when a fistful squeezed, 3-5 drops of water should drip). The worms need to be protecting also from their predators such as birds, rats, toads and from flooding. The rate of Vermi composting depends on the density of earthworms, the substrate composition (carbon-to-nitrogen ratio) and environmental conditions (temperature and moisture content).
The more worms stocked, the faster the production of castings. When the substrate fully composted in four to five weeks (28 to 35 days), the Vermi compost can be harvest. The earthworms is first removed from the pile by hand or through a mechanical sorter and then the compost are air-dried for two to three days to a moisture content of 30 percent.
For Vermi composting units located outdoors like on the farm or in the backyard, the substrate can be heaped in beds or windrows, which may be lined at the sides with bamboo walling or other forms of retaining devices such as screens and blocks. Beds can be stacked at a maximum height of 60 cm (2 feet) for aeration by earthworms.
The next step is the anaerobic stage wherein the bed covered with a plastic sheet to step up the natural decomposition initiated by anaerobic bacteria. The temperature of the substrate in this stage can reach 50-70° Celsius. "The higher the temperature, the faster the decomposition would take place."
This phase may last for one to two weeks. When the temperature of the substrate goes down to ambient condition (24-28° Celsius), the plastic cover of the Vermi composting unit is removed. Aerobic decomposition proceeds by stocking live earthworms into the substrate at the rate of one kilogram of worms per 20-30 kilograms of substrate (dry weight).
The Vermi composting units should be water when necessary to maintain the optimum moisture content of 60-80 percent (when a fistful squeezed, 3-5 drops of water should drip). The worms need to be protecting also from their predators such as birds, rats, toads and from flooding. The rate of Vermi composting depends on the density of earthworms, the substrate composition (carbon-to-nitrogen ratio) and environmental conditions (temperature and moisture content).
The more worms stocked, the faster the production of castings. When the substrate fully composted in four to five weeks (28 to 35 days), the Vermi compost can be harvest. The earthworms is first removed from the pile by hand or through a mechanical sorter and then the compost are air-dried for two to three days to a moisture content of 30 percent.
