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close this bookEnvironmentally Sound Technologies for Women in Agriculture (IIRR, 1996, 213 p.)
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View the documentVermi-composting
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What is vermi-composting?

Vermi-composting is the process by which earthworms convert organic waste into fertile manure. With a little knowledge of earthworms and an investment of time and some inexpensive materials, you can fertilize your garden with rich vermicompost.

Living composters

Earthworms live in the soil, mixing it, making it porous as they help decompose soil organic matter. Earthworm casts are the excrete of earthworms. These casts contain five times the nitrogen of ordinary soil, seven times the phosphorus, eleven times the potash, two times the calcium and magnesium, and eight times the actinomycetes (useful bacteria).


- feed on soil and soil organic matter and convert it to compost, making the soil rich in nutrients.

- encourage growth of useful micro-organisms, which also make soil rich.

- aerate and pulverise soil.

- are natural tillers of the soil.

- make soil porous, improving drainage.

- increase the water-holding capacity of soil.

- produce enzymes, hormones, vitamins, and antibiotics, thereby increasing immunity of plants against some pests.

Advantages of vermi-compost over other fertilizers

- Low cost to produce

- Easy to use

- Not harmful to useful soil organisms

- Converts organic matter to useful plant food

- Source of income

Advantages of vermi-compost over other fertilizers

Earthworms suitable for vermi-composting There are two types of earthworm:

Surface feeders convert waste matter into humus. Surface feeders are needed for vermi-composting. Certain species introduced from Africa are very efficient humus producers. They can be bought from companies which produce vermicompost. Some important species: Eisenia foetida, Eudrilus eugivae, Perionyx excavates, Lumbricus rubellus.

Deep feeder move soil and humus around and aerate the soil. Most Indian earthworm species are deep-feeders and are not suitable for vermi-composting.

Materials required for vermi-composting For a 10-sq-m plot:

- Dry organic matter-200-300 kg
- Decomposed farmyard manure 300-400 kg
- Organic wastes-700-800 kg
- Earthworms-10,000
- Water-ready supply

Method of preparation

1 Erect a shed 5 m wide and 12 m long.

2 Under the roof of this shed, build a long, thin rectangular (1 m wide and 10 m long) bed of organic matter 15 cm deep.

3 On top of this, spread a layer of decomposed manure or biogas slurry 15 cm deep.

4 Moisten the bed with water and leave it for 48 hours.

5 Place earthworms uniformly at the rate of 1,000 per sq m on the top layer.

Raised bed

6 Spread a 20-cm layer of organic wastes, litter, etc., over the earthworms.

7 Cover with gunny cloth and sprinkle water regularly to keep the plot wet. During summer months, you might have to sprinkle water twice a day.

8 Turn the material after 30 days, cover it again with gunny cloth and keep it moist.

9 The whole material is converted to humus, called vermicompost, in 65-70 days.

10 You can build a second bed next to the first. Use the earthworms from the first bed to repeat the process. Two beds of this type will produce about 1 tonne of vermicompost every 3 months.

Cover and keep moist.

Turn after 30 days.

Replace cover and keep moist.

Application of vermi-compost

Field-2.5 tonnes per hectare

Pots-50 grams per pot

Trees-apply vermi-compost at the rate of 100-200 g per tree, or place 100-200 worms around the tree trunk.


Under ideal conditions, earthworms multiply 20 to 25 times in
65-70 days. Use a sieve to separate the vermi-compost from the earthworms.
Use the earthworms to repeat the above process to make vermi compost throughout the year.

Keep moist

- Surface-feeding earthworms can survive only if the surface soil is kept moist. This can be done with drip irrigation. (See

Efficient use of irrigation water.)

- Where surface soil dries out, apply vermicompost each year at the beginning of the rainy season.

Developing an earthworm population

You can develop an earthworm population by placing earthworms or worm casts in the soil. After this, it is not necessary to apply vermi-compost; simply apply organic matter which the worms will convert into compost.


Take care to maintain an optimum number of earthworms in your fields. Their population is adversely affected by:

- use of chemical fertilizers.
- use of certain pesticides against soil-borne pests.
- inappropriate cultivation techniques, like use of rotary cultivators.
- acidification of soil.
- insufficient organic matter in the soil.

Earthworms are your friends. Protect them and nurture them in your fields. Adding vermi-compost and reducing the application of inorganic fertilizers will increase populations of deepburrowing earthworms, which turn over and aerate the soil.

Contributors: Dr. W.R. Deshpande, Dr. Chitra Srivastara and Dr. Jagdish Singh