Vermicompost and vermiwash are the two earthworm products that have become very popular nowadays. Ordinary organic garbage which consists of litter, such as, kitchen waste and dead plant material is used and converted into manure with the help of earthworms.
Earthworms
There are three kinds of earthworms. One, the epigeal or surface earthworm (Perionyx excavatus) which eats only organic litter which is present on the top layer of the soil. Two, the anecic earthworms (Lampito mauritii) which are present in the upper layers of soil and feed on waste and leaf litter. The third kind are present deep inside the soil and are known as endogeic earthworms (Octochaetona thriretonis).
The most suitable earthworms recommended for vermiculture are the epigeic and anecic earthworms. Perionyx excavatus is purplish red and rough. Near the two ends the Perionyx excavatus is almost black in colour. It is smaller and thinner (approx. 10 cms long) and more active compared to the Lampito mauritii. They also breed faster than Lampito mauritii. Lampito mauritii are greyish white in colour and shiny, thicker and longer (length-16 cms) compared to Perionyx excavatus.
Earthworms prefer cool temperatures, moist soil, humidity, relatively less sunlight and neither too coarse nor too fine sand. These are the ideal conditions that must be kept in mind when using them for vermiculture. Since earthworms breathe through the skin, they perish if their skin becomes dry or the quantity of mucus diminishes. Hence to keep earthworms alive in the vermicompost containers, care should be taken to ensure that the vermibed remains moist. Earthworms however do not prefer waterlogged soils. In fact if earthworms are kept in water for too long, the concentration of ammonia that is discharged through their excreta makes the water too toxic for the earthworms to survive. Earthworms also cannot tolerate salt or salt water even briefly.
Earthworms are hermaphrodites. Depending on the species, their life span is between six months to one year. Fully matured earthworms upon mating shed their clitellum (a small band like an overgrowth of skin) and produce cocoons which take about 14 days to incubate and hatch into juveniles. Maximum three juveniles are hatched from each cocoon. From the juvenile to the clitellate stage i.e. the fully matured or reproductive stage it takes 15-18 days. Thus earthworms are able to multiply several times in their life span which makes them ideally suited to process even large quantities of garbage.
Vermicompost
A pit, a small plastic or wooden crate or, even a bucket, can be used for vermicomposting organic matter. Although not necessary, two crates can be used simultaneously; while one is being used for fresh garbage, the garbage in the other can be allowed to decompose.
First, 6-8 holes should be made (one at each corner and four in the middle of the crate). A pot or a bucket needs about 3-5 holes. The crate or pit must first be filled with a one inch layer of pebbles or broken bricks. Then, a half to one inch layer of sand should be spread. Over that, a five to six inch layer of soil should be spread. Then Lampito mauritii and Perionyx excavatus earthworms should be introduced. The soil must then be moistened with water. A little bit of cowdung (nitrogen) and some hay (carbon) should be spread on it, and the contents of the pit left for 20-30 days. This is called a vermibed. The cowdung and hay will allow the worms to multiply. With this, the vermicompost crate or pit will be ready for processing organic waste.
All organic waste should be evenly spread out on the vermibed. As far as possible add garbage in small quantities regularly rather than dumping large quantities at one go. The earthworm begins processing the garbage immediately. Water the container occasionally so that the vermibed remains moist. Once the container is full with organic waste, it should be covered with a little soil and allowed to decompose undisturbed. Only watering the pit should continue. After it has decomposed fully (roughly 45 days) watering must be stopped for about 3 to 5 days. This will force the earthworms to migrate down to the bottom of the container which will have some moisture as compared with the top soil. Then the top layer of soil which is really the organic matter which has been converted into manure should be removed without disturbing the vermibed. This organic manure can be used for plants.