**4. Conventional steps involved in vermicomposting**

Prior to the vermicomposting process, it is preferred to assign pre-composting of organic waste (thermophilic composting), which comprises a short period of high temperature for facilitating mass reduction, waste stabilization, and pathogen reduction [61, 62]. Thermophilic composting results in sanitization of organic wastes and elimination of toxic compounds [63]. Although pathogen removal occurs during transit in the worm gut [64] but thermophilic composting prior to vermicomposting is advisable to avoid the earthworm mortality. Then, after some days of high temperature, pre-mature compost is cooled by spreading it as thin layers on vermicomposting beds. Vermicomposting can be done either in containers, pits or piles.

	- i.**High absorbency**: As earthworms breathes through their skins and therefore bedding must be able to absorb and retain water fairly well. Worms dies if its skin dries out.
	- ii.**Good bulking potential**: Worms respire aerobically and different bedding materials affect the overall porosity of the bedding, including the range of particle size and shape, the texture, and the strength and rigidity of its structure. If bedding material is too dense or packs too tightly, then the flow of air is reduced or eliminated. This overall effect is referred as the material's bulking potential.
	- iii.**Low protein and/or nitrogen content/high Carbon:** Earthworms consume their bedding as it breaks down and it is very important for this process to be slow. High protein/nitrogen levels can result in rapid degradation of bedding and its associated heating, creating inhospitable or fatal conditions. High carbon content is required as earthworms and microbes in the feed mixtures activate microbial respiration and degradation of organic wastes, thereby increasing the loss of organic carbon during the vermicomposting process [65, 66]. Various bedding material according to absorbency, bulking potential and C:N are enlisted in **Table 1**.

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**Table 1.**

*List of some of the commonly used earthworm bedding material.*

*Vermicomposting: An Effective Option for Recycling Organic Wastes*

collected for use in the next batch of vermicomposting.

weather conditions such as frost, heavy rainfall, drought and overheating should be avoided. No smell comes out of composting site if the right products or bedding and feed are used. The vermicompost once formed completely will give the smell of moist soil. Maturity could be judged visually also by observing the formation of granular structure of the compost at the surface of the tank. Next step is to make a heap in sunlight on a plastic sheet and keep it for 1-2 hours. The worms will gather at the bottom of heap. After removing vermicompost on top, the worms settled down at the bottom can be carefully

**Bedding Material Absorbency Bulking Pot. C:N Ratio** Horse manure Medium-good Good 22–56 Peat moss Good Medium 58 Corn silage Medium-Good Medium 38–43 Hay–general Poor Medium 15–32 Straw–general Poor Medium-Good 48–150 Straw–oat Poor Medium 48–98 Straw–wheat Poor Medium-Good 100–150 Paper from municipal waste stream Medium-Good Medium 127–178 Newspaper Good Medium 170 Bark–hardwoods Poor Good 116–436 Bark–softwoods Poor Good 131–1285 Corrugated cardboard Good Medium 563 Lumber mill waste–chipped Poor Good 170 Paper fibre sludge Medium-Good Medium 250 Paper mill sludge Good Medium 54 Sawdust Poor-Medium Poor-Medium 142–750 Shrub trimmings Poor Good 53 Hardwood chips, shavings Poor Good 451–819 Softwood chips, shavings Poor Good 212–1313 Leaves (dry, loose) Poor-Medium Poor-Medium 40–80 Corn stalks Poor Good 60–73 Corn cobs Poor-Medium Good 56–123 Paper mill sludge Good Medium 54 Sawdust Poor-Medium Poor-Medium 142–750 Shrub trimmings Poor Good 53 Hardwood chips, shavings Poor Good 451–819 Softwood chips, shavings Poor Good 212–1313 Leaves (dry, loose) Poor-Medium Poor-Medium 40–80 Corn stalks Poor Good 60–73 Corn cobs Poor-Medium Good 56–123

*DOI: http://dx.doi.org/10.5772/intechopen.91892*

*Organic Agriculture*

5.**Earthworm bed preparation:** An hospitable living environment for worms called bedding is prepared. Bedding is a material that provides the worms with

i.**High absorbency**: As earthworms breathes through their skins and therefore bedding must be able to absorb and retain water fairly well. Worms

ii.**Good bulking potential**: Worms respire aerobically and different bedding materials affect the overall porosity of the bedding, including the range of particle size and shape, the texture, and the strength and rigidity of its structure. If bedding material is too dense or packs too tightly, then the flow of air is reduced or eliminated. This overall effect is referred as the

consume their bedding as it breaks down and it is very important for this process to be slow. High protein/nitrogen levels can result in rapid degradation of bedding and its associated heating, creating inhospitable or fatal conditions. High carbon content is required as earthworms and microbes in the feed mixtures activate microbial respiration and degradation of organic wastes, thereby increasing the loss of organic carbon during the vermicomposting process [65, 66]. Various bedding material according to

iii.**Low protein and/or nitrogen content/high Carbon:** Earthworms

absorbency, bulking potential and C:N are enlisted in **Table 1**.

compacted to prevent earthworm's migration into the soil.

50% of the wastes, it consumes in a day.

6.**Vermiculture bed:** Vermiculture bed can be prepared by placing a first layer of saw dust, newspaper, straw, coir waste, sugarcane trash etc. at the bottom of tub/container. Newspaper is one of bedding material that high in absorbency whereas for the sawdust the level of absorbency is poor to medium. A second layer of moistened fine sand of 3 cm thick should be spread over the culture bed followed by a layer of garden soil (3 cm). The floor of the unit should be

7.**Loading of organic waste mixture in bed:** Third layer of the pre-digested organic waste prepared is added. Thereafter a thin layer of cow dung mixture is placed on the surface of waste material as starter food for compost worms. Then compost worms are to be added without spreading them out. Earthworms consume various organic wastes and reduce the volume by 40–60%. Earthworm eats waste equivalent to its body weight, and produce cast about

8.**Composting process:** After addition of compost worms wait for at least 15 days for the thermophillic process to end. During this process there is a rapid increase in temperature followed by a gradual decrease. During this period turning to the material 2–3 times at 4–5 days interval is required. Its temperature should be maintained at 30°C, when temperature approaches ambient temperature (<35°C) covering is to be removed and for temperature maintenance, upturning and regular sprinkling of water is advisable. Prominent precautionary measures include; Composting pit should be covered with nylon net or any substitute material to serve as barrier against predators like ants, birds, lizards as it may disturb the activity of earthworm, Blockage of side air vents should be avoided as it can quickly lead to putrefaction and extreme

a relatively stable habitat with following characteristics:

dies if its skin dries out.

material's bulking potential.

**50**

weather conditions such as frost, heavy rainfall, drought and overheating should be avoided. No smell comes out of composting site if the right products or bedding and feed are used. The vermicompost once formed completely will give the smell of moist soil. Maturity could be judged visually also by observing the formation of granular structure of the compost at the surface of the tank. Next step is to make a heap in sunlight on a plastic sheet and keep it for 1-2 hours. The worms will gather at the bottom of heap. After removing vermicompost on top, the worms settled down at the bottom can be carefully collected for use in the next batch of vermicomposting.


#### **Table 1.**

*List of some of the commonly used earthworm bedding material.*
