VERMICOMPOSTING

 VERMICOMPOSTING

 

Vermicomposting is a composting process aided by earthworms. Earthworms can consume anything organic in nature. They consume daily about 2 to 5 times their body weight, retain 5 to 10% of the feedstock for their own growth. Ingested food, after going through physical and chemical breakdown through the activity of muscular gizzard present in the intestine they excrete the mucus coated undigested matter known as vermicast. It has been estimated that 1 ton of moist organic matter can be converted into 300 kg of compost by earthworms. The casting of earthworms is rich in nutrients (N, P, K & Mg) which are in readily available form. The main advantage of the use of earthworms for composting of a wide variety of organic residues is the reduced time required for the maturity of composting

 

Earthworm Species for Vermicomposting: 

There are about 3000 species of earthworm in India which can be classified broadly as surface living (epigeic) and burrowing (epianecic) worms. Epigeic or compost worms are found on the surface and reddish-brown in colour (red worm). Other species (epianecic) burrow and mix the soil from the different horizons in the profile and ingest organic and the mineral fraction of soil thereby promote the formation of organo-mineral complexes. Of the many species of earthworms tested for mass culture all over the world, Eisenia foetida, Pherritima elongate, Eudrilus eugeniae, Perionyx excavates come in the above order of preference for their ability to compost organic wastes.

 

 Steps for vermicomposting: 

1. Any convenient size pit or tank with dimensions such as 14ft x 3.5ft x 1.5ft may be prepared. A thick layer of 15 to 20 cm of good loamy soil above a thin layer of 5 cm of broken bricks and sand should be laid down. This layer is made to inhabit the earthworm and it is known as vermibed.

2. All forms of biologically degradable and decomposable organic wastes can be used as raw material. Crop residues, banana stems, kitchen waste, etc. can be used as raw materials. Fresh cattle dung is an important raw material for vermicomposting. 

3. The pits should be filled with organic materials and cow dung slurry as the medium. And water the pit twice a day to enhance the early decomposition of raw materials and covered it with gunny bags to decrease the loss of moisture. 

4. Turning should be done at 15-20 days interval to provide aeration for early decomposition

 5. Raw materials generally get decomposed in around 40-45 days upon regular watering. Earthworms should be released on the top of the bed to feed on the organic materials and cover them with gunny bags to maintain moisture. 

6. A fully matured and well-decomposed vermicompost gives an appearance of tea leaves and is usually does not gives a foul odour also. Well-maintained vermicompost is ready to be harvested after 2-3 months. It is very important to stop watering 10 days before harvesting to allow the earthworms to settle down in the lower layers 

7. To separate the vermicompost, undecomposed substrates, and earthworms from each other sieving are done. This can be done manually using the same sieve which is used for masonry work to screen out rough sand. 

 

Advantages of Vermicompost:

 

 1. Organic:

 The most important aspect of compost produced by earthworms is that it is organic. 

2. More Nutritious: 

Vermicompost benefits plants in several different ways. The most significant being the nutrients in vermicompost are very easily absorbed by the roots of plants.

3. Micro-Organisms:

 As composting involves passing through the body of the worms it is enriched with bacteria and microbes. These help plants resist pests. The presence of the increased microbial activity attracts birds which also helps to remove plant pests. 

4. Healthier Plants:

 As the compost works on the plants and they become healthier and they become resistant to pest attack and hence the need for pesticides is reduced. 

5. Plant Growth: 

Germination of seeds is boosted, the growth of the plant is stronger and the crop yield increases. The distribution of the compost through the soil is also enjoyed by the roots for their healthy growth.

6. Water Holding capacity:

 Being colloid vermicompost can hold up water to nine times its weight. This can be a boon when there is a dry spell. 

7. Slow Release of Nutrients:

 When chemical fertilizers are supplied to the plants they are bombarded with huge amounts of nutrients that are going to drain by and eventually be washed out of the soil by the rain. The chemicals can get into the groundwater and contaminate them. Using compost that is lower in nutrient content but does not get washed out of the soil. The nutrients are released slowly so that the plants receive what they need over a prolonged period.