VERMICOMPOST-PRODUCTION & PRACTICES

Vermicomposting is a method of preparing enriched compost with the use of earthworms. It is one of the easiest methods to recycle agricultural wastes and to produce quality compost. Earthworms consume biomass and excrete it in digested form called worm casts. Worm casts are popularly called as Black gold. The casts are rich in nutrients, growth promoting substances, beneficial soil micro flora and having properties of inhibiting pathogenic microbes.

Vermicompost is stable, fine granular organic manure, which enriches soil quality by improving its physicochemical and biological properties. It is highly useful in raising seedlings and for crop production. Vermicompost is becoming popular as a major component of organic farming system

Composting is the process by which biomass is broken down to humas, which has several beneficial effects on soil physical and chemical properties. Further decomposition of humas releases the nutrients contained in it for crop uptake. A requirement for composting is organisms that feed on biomass and break it down to physically finer particles and chemically less complex substances. In nature, earthworms and microorganisms decompose dead biomass. When this process is initiated with the deliberate introduction of earthworms into a stack of biomass, it is called vermicomposting.

why vermicomposting is preferred to other methods of composting. Of the limited biomass available, farmers use straw, leaf litter and tender stem as fodder for farm animals while hardy stem and coarse leaf are sources of domestic fuel. The leftover biomass, after these immediate priorities are met, is coarse material that does not break down easily. In such material, earthworms are more effective in initiating the decomposition process and paving the way for subsequent microbial action.

Another source of biomass available to farmers is cattle dung. It is an excellent substrate that undergoes composting on its own and becomes farmyard manure of very high quality. Unfortunately, the dung available with small farmers does not compost well because of the state in which it is available. Animals owned by them usually graze in the open and the dung is relatively dry when collected. It is then left in a collection pit where it loses more moisture. Therefore, dung collected in the open, unlike fresh dung, does not have the microbial populations in required numbers to decompose into farmyard manure. However, it becomes an excellent substrate for vermicomposting when wetted.

The India government has launched the ‘Gobardhan Yojana’ to provide for the sale of organic manure and cow urine with an aim to benefit farmers. The Gobardhan Yojana would help in doubling the income of farmers .Its really a great step taken by our visionary PM to encourage such rural based organic practices to make people healthy lifestyle.

• The chief objective is to compost organic wastes not for the disposal of solid organic wastes but also to produce superior quality manure to feed our “nutrient/organic matter hungry” soils.

• Large volume of organic matter generated from agricultural activities, dairy farms and animal shelters usually dumped in corners emanating foul smell, can be utilized by properly composting it into a value-added end product

Decomposable organic wastes such as animal excreta, kitchen waste, farm residues

and forest litter are commonly used as composting materials. In general, animal dung

mostly cow dung and dried chopped crop residues are the key raw materials. Mixture

of leguminous and non-leguminous crop residues enriches the quality of vermicompost.

There are different species of earthworms viz. Eisenia foetida (Red earthworm), Eudrilus eugeniae (night crawler), Perionyx excavatus etc. Red earthworm is preferred because of its high multiplication rate and thereby converts the organic matter into vermicompost within 45-50 days. Since it is a surface feeder it converts organic materials into vermicompost from top.

• Out of two thousand five hundred species of earthworms identified in the world, more than five hundred species of earthworms have been identified in India.

• Earthworm diversity varies with soils and choosing a native species for vermicomposting is necessary and there is no need to import them.

• Local species used in India are Perionyx excavatus and Lampito mauritii.

• These earthworms can be cultured or used in composting applying simple procedures either in pits, crates, tanks, concrete rings or any containers.

• Identify worm-inhabited soils marked by visible earthworm castings on the soil surface.

• Dissolve 500 g jaggery (native sugar) and 500 g fresh cattle dung in 2 litres of water and sprinkle on an area 1m × 1m surface soil.

• Cover with straw lumps and cover with an old gunny bag.

• Keep sprinkling water for about 20 to 30 days.

• Native worms will aggregate in the spot and can be collected and used.

The types of vermicomposting depend upon the amount of producton and composting structures. Small-scale vermicomposting is done to meet the personal requirement and farmer can harvest 5-10 tonnes of vermicompost annually. While, large-scale vermicomposting is done at commercial scale by recycling large quantity of organic waste with the production of more than 50 – 100 tonnes annually

Vermicromposting is done by various methods, among them bed and pit methods are more common.

Bed method : Composting is done on the pucca / kachcha floor by making bed (6x2x2 feet size) of organic mixture. This method is easy to maintain and to practice  (Fig.1).

Pit method: Composting is done in the cemented pits of size 5x5x3 feet. The unit is covered with thatch grass or any other locally available materials. This method is not preferred due to poor aeration, water logging at bottom, and more cost of production (fig.2)

• Compost pit of any convenient dimension can be constructed in the backyard or garden or in a field.

• It may be single pit, two pits or tank of any sizes (manageable size is 2 m x 1m x 0.75 m) with brick and mortar with proper water outlets.

• To combat the ant menace, have a water column in the centre of the parapet wall of the vermipits

• The ‘four chamber’ pit will facilitate easy and continuous movement of earthworms from one chamber with fully composted matter to the one with the pre-processed waste in the chambers

• Vermibed is the layer of moist loamy soil placed at the bottom, about 15 to 20 cm thick above a thin layer (5 cm) of broken bricks and coarse sand.

• Earthworms are introduced into the loamy soil, which the worms will inhabit as their home.

• 150 earthworms may be introduced into a compost pit of about 2m x 1m x 0.75m, with a vermibed of about 15 to 20 cm thickness.

• Handful lumps of fresh cattle dung are then placed at random over the vermibed.

• The compost pit is then layered to about 5 cm with dry leaves or preferably chopped hay/straw or agricultural waste biomass.

• For the next 30 days the pit is kept moist by watering it whenever necessary.

• The bed should neither be dry or soggy.

• The pit may then be covered with coconut or Palmyra leaves or an old jute (gunny) bag to discourage birds.

• Plastic sheets on the bed are to be avoided as they trap heat.

• After the first 30 days, wet organic waste of animal and/or plant origin from the kitchen or hotel or hostel or farm that has been pre-digested is spread over it to a thickness of about 5 cm. Repeat this twice a week.

• All these organic wastes can be turned over or mixed periodically with a spade.

• Regular watering should be done to keep the pits moist.

• If the weather is very dry, it should be checked periodically.

• The compost will be ready in 60 to 90 days and the material becomes moderately loose, crumbly with dark brown colour. It will be black, granular, lightweight and humus-rich.

• Presence of earthworm castings (vermicompost) on the top of the bed is also an indicator and vermicompost can be harvested.

• Stop watering two to three days before emptying the beds to facilitate separating the worms from the compost (80 per cent of the worms will move to the bottom of the bed).

• The harvested material should be placed in a heap in the sun so that most of the worms move down to the cool base of the heap.

• In the two or four pit system, watering should be stopped in the first chamber so that worms will automatically move to another chamber where the required environment for the worms are maintained in a cyclic manner and harvesting can be done continuously in cycles.

• The worms can be separated by using sieves/meshes.

• The earthworms and the thicker material, which remains on top of the sieve, are recomposted.

• The smell of the compost is earth-like.

• Any bad odour if formed is a sign that fermentation has not reached its final goal and that the bacterial processes are still going on.

• A musty smell indicates the presence of mold or overheating which leads to loss of nitrogen.

• If this happens, aerate the heap better or start again, adding more fibrous material and keeping the heap drier.

• The compost is then sieved before being packed.

The level of nutrients in compost depends upon the source of the raw material and the species of earthworm. A fine worm cast is rich in N P K besides other nutrients. Nutrients in vermicompost are in readily available form and are released within a month of application.

Parameters     Content

pH                    6.8

OC%                       11.88

OM%                        20.46

C/N ration                 11.64

Total Nitrogen (%)               1.02

Available N (%)                 0.50

Available P (%)                  0.30

Available K (%)                    0.24

Ca (%)                               0.17

Mg (%)                   0.06

• Organic wastes can be broken down and fragmented rapidly by earthworms, resulting in a stable nontoxic material with good structure, which has a potentially high economic value and also act as soil conditioner for plant growth.

• Vermicompost supplies a suitable mineral balance, improves nutrient availability and could act as complex-fertilizer granules.

• Vermicomposting involves great reduction in populations of pathogenic microorganisms, thus not differing from composting from this point of view.

• Vermicomposting also leads to decrease the environmental problems arising from their disposal, without needing in many cases to complete the process.

• It should be realized that vermicomposting can be a useful cottage industry for the underprivileged and the economically weak as it can provide them with a supplementary income.

• If every village can formulate a cooperative society of unemployed youth/women group, it could be a wise venture for them to produce vermicompost and sell it back to the village at a recommended price. The youth will not only earn money, but also aid society by providing excellent quality organic manure for sustainable agro-practices.

When raw material is completely decomposed it appears black and granular. Watering

should be stopped as compost gets ready. The compost shout be kept over a heap of

partially decomposed cow dung so that earthworms could migrate to cow dung from

compost . After two days compost can be separated and sieved for use .

• The floor of the unit should be compact to prevent earthworms’ migration into the soil.

• 15-20 days old cow dung should be used to avoid excess heat.

• The organic wastes should be free from plastics, chemicals, pesticides and

metals etc.

• Aeration should be maintained for proper growth and multiplication of earthworms.

• Optimum moisture level (30-40 %) should be maintained

• 18-25oC temperature should be maintained for proper decomposition.

The doses of vermicompost application depend upon the type of crop grown in the field/nursery. For fruit crops, it is applied in the tree basin. It is added in the pot mixture for potted ornamental plants and for raising seedlings. Vermicompost should be used as a component of integrated nutrient supply system.

Field crops 5-6t/ha

Fruit crops 3-5kg/plant

Pots 100-200g/pot

Vermicomposting is a highly profitable venture for farmers having dairy units. The

approximate cost and benefit under different scale of production is given below.

Scale App.cost per App.benefit per Cost/benefit ratio

annum (Rs) annum (Rs)

Small 52,000 90,000 1 : 1.73

Medium 1.0 lakh 1.85 lakh 1 : 1.85

Large 2.25 lakh 4.5 lakh 1 : 2.0

Step 1: Cover the bottom of the cement ring with a polythene sheet. (Or use the sheet to cover the ground of the area you’re using).

Step 2: Spread a layer (15-20 cms) of organic waste on top of the sheet.

Step 3: Sprinkle rock phosphate on top of the organic material (2kgs).

Step 4: Prepare cowdung slurry (15kgs) and add the slurry as a layer on top of the mixture.

Step 5: Fill the ring completely and evenly with the layered material.

Step 6: Paste cowdung or soil over the top of the material.

Step 7: Allow the material to decompose for 20 days. After 20 days, put the earthworms on top. They will find the cracks and enter the material.

Step 8: Cover the ring with wire mesh or gunny bags to prevent birds from eating the worms.

Step 9: Sprinkle water over the whole mixture at 3-day intervals for 2 months, to maintain adequate moisture and body temperature of the worms.

* Note: when the compost is ready, it is black, quite lightweight and has a pleasant, earthy smell.

Step 10: After 2 months, (or when the compost is ready), remove the ring and heap the material in a cone shape on the floor. Leave the heap undisturbed for 2-3 hours, to let the worms move slowly to the bottom.

Step 11: Separate the upper portion of the heap.

Step 12: Sieve the lower portion of the heap to separate the worms. They can be used again for preparation of more vermicompost.

Step13: Pack the compost in bags and store them in a cool place.

Vermicompost is ready in 2 to 2.5 months. When it’s ready, it’s black, lightweight and has no bad smell.

What are the additional precautions?

• Use only plant materials (such as vegetable peelings, leaves or grass)

• Remove glass, metal and plastic materials from the organic material

• Protect against birds by covering the rings with wire or plastic mesh

• Sprinkle water regularly and maintain moisture levels

• Prepare compost in the shade to protect it from sun and rain.

Vermicompost can be used for all crops (agricultural, horticultural, ornamental and vegetable) at any stage of the crop development.

• Agricultural Crops: apply vermicompost by broadcasting when the seedlings are 12-15 cms in height. Irrigate the field(s).

• Flowers, Vegetables and Fruit Trees: apply vermicompost around the base of the plant, at any stage of development, and cover with soil. Water regularly.

• General Agricultural Use: 3-4 tonnes ha-1

• Fruit Trees: 5-10 kg per tree

• Vegetables: 3-4 tonnes ha-1

• Flowers: 500-750 kg ha-1

1. What are the costs?

Costs for are quite low. Examples are as follows:

Rock Phosphate: 2 Rupees per kg

Worms: 50 Rupees per kg

* Note: these are only examples of prices in India and are subject to change.

2. Where can the products be obtained or purchased?

WORMS: The non-burrowing worms are often found in local markets.

ROCK PHOSPHATE: Is available with local fertilizer dealers.