In general terms vermiculture means the cultivation of earthworms in order to use them to convert organic waste to nutrient and beneficial microorganism rice fertilizer. It allows us to grow organically rich compost year-round. Vermiculture was first introduced in the 1970s by a biology teacher, Mary Appelhif. She developed the idea of using red wiggler worms (Eisenia fetida) for composting in indoor and outdoor systems to convert kitchen waste to worm compost.
There are three major techniques in vermiculture for harvesting worms. These are
Manual Method of Harvesting
This method is generally used by framers for small-scale businesses selling worms. The worms are harvested from the soil directly by using hands. The organic material which contains earthworms is kept on a flat surface and exposed to sunlight. It should be noted that earthworms are sensitive to light, so once they are exposed to sunlight they dive below the surface. The harvester will then remove the organic layer above and once the worms are seen they are harvested.
Migration Method of Harvesting
This method takes advantage of the earthworm’s tendency to migrate to a new location for food and for this reason, onion bags and screens are used for harvesting. At the bottom surface of the screen, a box will be constructed where the worms would be collected. The migration method is carried out in two ways.
The downward migration method is where the worms are forced to move downwards in the organic material with the use of light. They will go through the screen mesh and be collected in the container box below which is filled with peat moss. The process is repeated until the required quantity of worms has been achieved. It is a time-saving process and can be seen in multiple locations.
In the upward migration method, the mesh bottom of the box would be replaced by a worm bed. The box will be filled with peat moss and food which attracts the worms. Generally, coffee grounds and manure from fresh cattle are used as food for worms and they will move towards it and be collected in the box.
Mechanical Method of Harvesting
In this method, a mechanical harvester is used to collect worms. It is a trammel screen which is called a rotary screen that is used to separate materials. It is around 11ft long and 4ft in diameter and has a cylindrical shape. The walls of the cylinder are made of screening materials with different sized meshes. The cylinder is powered by an electric motor. The device would be set at an angle at the top side of the trammel. After that, the castings and the worm beds are added. When the rotation starts the castings of the worms will drop through the screen and the worms will move across the trammel device and enter into the wheelbarrow.
The method used by farmers to multiply earthworms is by mixing high amounts of organic wastes, including the plant materials, cattle dung in a proportion of 1:1. Once the substrate medium has been made, around 40-50 earthworms species are released into the medium and it is protected from various environmental factors.
Regular maintenance is important for the growth of earthworms. The temperature should be between 15 to 25-degree centigrade and the moisture level should be at 80-90%. Within one to two months, the earthworms can multiply up to 300 times relying on this process and factors affecting the process, and then they can be harvested.
Materials Required for Vermicomposting:
Waste from agro-industries
A suitable container
Preparation of Vermicomposting
A container with suitable dimensions is chosen and a worm bed is made at the pit of the container. This worm bed consists of old papers, sugar cane trash, paddy husk, and coir waste. A thin layer of soil is spread over this mixture and the humidity is maintained at 40-45%
A mix of organic waste, slurry from a biogas plant, and cattle dung is spread over the bed and it is kept for half digestion for a period of two weeks. During this time, the temperature of the bedding will rise to 50-55 degrees centigrade. A 5-10% neem cake is added to eliminate harmful microorganisms.
After the temperature is cooled down to 30 degrees, the earthworms are introduced. Around 500 earthworms are introduced for 100 kgs of organic material.
The bed is covered with straw and jute clothes to protect the worm. The temperature is maintained at 20-30 degrees centigrade and the moisture content is kept at 45-50%. (pH: 6.5-7)
The compost will be ready in around 60 days and after it is ready the worms are separated by spreading the vermicompost on a plastic sheet in a heap under sunlight. As earthworms are sensitive to sunlight, they will move to the bottom of the heap and the top layer of the compost can be removed.
Vermicompost is eco-friendly and it can help in reducing landfill
The warm liquid at the bottom of the worm bin is great for the growth of garden plants. It is also known as worm tea.
Worm casting can improve soil fertility by enriching it with nutrients.
Worms have no eyes, no ears, and 5 hearts.
They breathe through their skin.
They are species of earthworms, they are rarely found in the soil unless seeded prior.
When healthy, they can eat about half of their body weight in food each day.
They are hermaphroditic (they have both male and female sex organs) but two worms are needed to reproduce.
The two worms join together and exchange sperm and both worms secrete cocoons that contain eggs.
Red Wigglers are used whereby the soil is; infertile due to excessive artificial fertilizer
Containing cancerous cells because of waste materials.
Natural restoration of soil.
The worms use their bodies to remove toxins in the soil.
They produce compost tea which is used to spray other plants as an insecticide.
We, therefore, urge Basotho to practice this method of farming as it protects the soil and improves its quality. Chemical fertilizers are highly harmful to the environment as they contain materials that are contagious in the long run and pollute the water.