Authors: Rajdeep Mundiyara1, and Mukesh Kumar Jat2
1Seed Officer, Rajasthan State Seeds Corporation,Mandore, Jodhpure
2 Department of Plant Pathology, Jobner
Email of corresponding author: rmundiyara5@gmail.com
Vermicomposting is the process by which worms are used to convert organic materials (usually wastes) into a humus-like material known as vermicompost. The goal is to process the material as quickly and efficiently as possible. Earthworms consume biomass and excrete it in digested form calledworm 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.
Vermiculture is the culture of earthworms. The goal is to continually increase the number of worms in order to obtain a sustainable harvest. The worms are either used to expand a vermicomposting operation or sold to customers who use them for the same or other purposes.
Species suitable for vermicomposting
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.
Important characteristics of red earthworm (Eisenia foetida)
Characters | : | Eisenia foetida |
Body length | : | 3-10 cm |
Body weight | : | 0.4-0.6 g |
Maturity | : | 50-55 days |
Conversion rate | : | 2.0 q/1500 worms/2 months |
Cocoon production | : | 1 in every 3 days |
Incubation of cocoon | : | 20-23 days |
It is an aerobic, bio-oxidation, non-thermophilic process of organic waste decomposition that depends upon earthworms to fragment, mix and promote microbial activity. The basic requirements during the process of vermicomposting are
- Suitable bedding
- Food source
- Adequate moisture
- Adequate aeration
- Suitable temperature
- Suitable pH
Vermicomposting materials
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.
Methods of vermicomposting
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.
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.
Vermiculture bed
Vermiculture bed or worm bed (3 cm) can be prepared by placing after saw dust or husk or coir waste or sugarcane trash in the bottom of tub / container. A layer of fine sand (3 cm) should be spread over the culture bed followed by a layer of garden soil (3 cm). All layers must be moistened with water.
Selection for vermicompost production
Cattle dung (except pig, poultry and goat), farm wastes, crop residues, vegetable market waste, flower market waste, agro industrial waste, fruit market waste and all other bio degradable waste are suitable for vermicompost production. The cattle dung should be dried in open sunlight before used for vermicompost production. All other waste should be predigested with cow dung for twenty days before put into vermibed for composting.
Putting the waste in the container
The predigested waste material should be mud with 30% cattle dung either by weight or volume. The mixed waste is placed into the tub / container upto brim. The moisture level should be maintained at 60%. Over this material, the selected earthworm is placed uniformly. For one-meter length, one-meter breadth and 0.5-meter height, 1 kg of worm (1000 Nos.) is required. There is no necessity that earthworm should be put inside the waste. Earthworm will move inside on its own.
Watering the vermibed
Daily watering is not required for vermibed. But 60% moisture should be maintained throughout the period. If necessity arises, water should be sprinkled over the bed rather than pouring the water. Watering should be stopped before the harvest of vermicompost.
Harvesting vermicompost
In the tub method of composting, the castings formed on the top layer are collected periodically. The collection may be carried out once in a week. With hand the casting will be scooped out and put in a shady place as heap like structure. The harvesting of casting should be limited up to earthworm presence on top layer. This periodical harvesting is necessary for free flow and retain the compost quality. Other wise the finished compost get compacted when watering is done. In small bed type of vermicomposting method, periodical harvesting is not required. Since the height of the waste material heaped is around 1 foot, the produced vermicompost will be harvested after the process is over.
Potential benefits of vermicomposting
- Vermicompost appears to be generally superior to conventionally produced compost in a number of important ways;
- Vermicompost is superior to most composts as an inoculant in the production of
- compost;
- Worms have a number of other possible uses on farms, including value as a high quality animal feed;
- Vermicomposting and vermiculture offer potential to organic farmers as sources of supplemental income.
- It restores microbial population which includes nitrogen fixers, phosphate solubilizers etc.
- Provides major and micro- nutrients to the plants.
- Improves soil texture and water holding capacity of the soil.
- Provides good aeration to soil, thereby improving root growth and proliferation of beneficial soil microorganisms.
- Decreases the use of pesticides for controlling plant pathogens.
- Improves structural stability of the soil, thereby preventing soil erosion.
- Enhances the quality of grains/ fruits due to increased sugar content.
- It can be quicker, but to make it so generally requires more labour;
- It requires more space because worms are surface feeders and won’t operate in material more than a meter in depth;
- It is more vulnerable to environmental pressures, such as temperature, freezing conditions and drought;
- Perhaps most importantly, it requires more start-up resources, either in cash (to buy the worms) or in time and labour (to grow them).
The nutrients content in vermicompost vary depending on the waste materials that are being used for compost preparation. If the waste materials are heterogeneous one, there will be wide range of nutrients available in the compost. If the waste materials are homogenous one, there will be only certain nutrients are available. 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. The common available nutrients in vermicompost is as follows
Organic carbon | : | 9.5 – 17.98% |
C/N ratio | : | 11.64 |
Nitrogen | : | 0.5 – 1.50% |
Phosphorous | : | 0.1 – 0.30% |
Potassium | : | 0.15 – 0.56% |
Sodium | : | 0.06 – 0.30% |
Calcium and Magnesium | : | 22.67 to 47.60 meq/100g |
Copper | : | 2 – 9.50 mg kg-1 |
Iron | : | 2 – 9.30 mg kg-1 |
Zinc | : | 5.70 – 11.50 mg kg-1 |
Sulphur | : | 128 – 548 mg kg-1 |
Earthworms serve as “nature’s plowman” and form nature’s gift to produce good humus, which is the most precious material to fulfill the nutritional needs of crops. Vermicompost can be used for all crops viz., agricultural, horticultural, ornamental and vegetables at any stage of the crop. The utilization of vermicompost results in several benefits to farmers, industries, environment and overall national economy.
To farmers:
• Less reliance on purchased inputs of nutrients leading to lower cost of production
• Increased soil productivity through improved soil quality
• Better quantity and quality of crops
• For landless people provides additional source of income generation
To industries:
• Cost-effective pollution abatement technology
To environment:
• Wastes create no pollution, as they become valuable raw materials for enhancing soil fertility
To national economy:
• Boost to rural economy
• Savings in purchased inputs
• Less wasteland formation
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