Dr. Banarsi Lal
Vermicomposting is a mesophilic process which involves a collective action of earthworms and mesophilic microbes for the conversion of organic wastes in to a valuable end product known as vermicompost. It is a biotechnological process in which certain species of earthworms are used to enhance the process of organic waste conversion and produce a better end product. It is said to be a mesophilic process using micro-organsisms and earthworms. Earthworms eats the organic waste materials and passes it through their digestive system and gives out in a granular form(cocoons) which is called as vermicompost.In other words, vermicompost is earthworms excrement called castings which improves the physical, chemical and biological properties of soil. The chemical sectretions in the earthworms digestive track breakdown the organic matter and soil. It contains all the nutrients required by the plants. Vermicompostinmg process is faster than simple composting. In short, earthworms through a type of biological alchemy are capable of transforming garbage into gold. Vermicomposting gives a higher quality end product than composting due to collective action of enzymatic and microbial activities that occur during the process.
The process of vermicomposting requires livestock wastes, poultry litter, crop residues / agri-wastes such as straw, husk, leaves etc. Earthworms consume organic wastes and reduce the volume by 40-60 per cent. Each earthworm weighs around 0.5 to 0.6 gram, eats equivalent amount of waste and produces about 50 per cent of the waste. The pH of casting is around 7 and its moisture content ranges between 32 and 66 per cent. There are about 3600 types of earthworms which are divided on the basis of burrowing and non-burrowing types. Red earthworm species such as Eisenia fetida are considered as the most efficient in compost making. These species are unpredictable and unstable habitats characterized by highly variable environmental conditions, food availability, and predation pressures. Under unfavourable conditions, these earthworms suffer high mortality. These species are ubiquitous, have short life cycles, have high reproductive rates and tolerant of wide range of temperatures and humidity and relatively easy to handle. Small scale vermicomposting is done by the farmers while commercial scale vermicomposting is done by the industries by recycling organic waste material by using the modern technologies.
Vermicompost contains higher percentages of nutrients than Farm Yard Manure (FYM) and these nutrients are easily available to the plants. Vermicompost improves the water retention capacity of the soil, enhances plant growth, suppresses diseases in plants, increases porosity and microbial activity in soil. It also improves the environment by reducing the use of chemical fertilizers and decreases the amount of waste going to the landfills. Use of vermicompost is increasing across the globe as it is helpful to produce the organic food. Vermicompost tea can also be prepared from vermicompost which is a liquid produced by extracting organic matter, micro-organisms and nutrients from vermicompost. This tea can be applied directly to the plant foliage to suppress the diseases. It can be used in the soil as a supplement to increase the biological activity in the soil. Vermicompost can be sold in bags/packets to the farmers, nursery growers, landscape contractors, general public, departments etc.
By using earthworms the agricultural wastes and dung can be gradually converted into vermicompost. Pits of different dimensions are used to prepare the vermicompot. The pits are kept moistened as it saves the lives of earthworms. The final product generated by this process is called vermicompost which essentially consists of the casts made by earthworms by eating the raw organic materials. The process consists of constructing brick lined beds which are constructed inside a shed open from all sides. For commercial production, the beds can be prepared according to the need of vermicompost. The ease of operation is always considered while making the beds. The units are always kept in shade. Animals dung and farm wastes can be placed in layers to make a heap of about 0.6 to 0.9 m height. Pits are filled in four layers.In1st layer, sand or sandy soil of 5-6 cm is kept. This layer helps to drain excess water from the pit. In 2nd layer crop residue or paddy straw of 30 cm above is kept. In 3rd layer, 15 to 30 days old dung over the crop residue at a thickness of 20-30 cm is kept. This helps in initiating microbial activity. In 4th layer, pre-digested material about 50 cm is kept. Earthworms are introduced in between the layers @ 350 worms per m3 of bed volume that weighs around 1 Kg. Then the pit is covered with jute bags. The beds are maintained at about 40-50% moisture content and a temperature of 20-30oC is maintained by sprinkling water over the beds. When compost is ready, it is removed from pit by sieving and worms are put back in the pits which are further used for vermicomposting. The undecomposed residues are put back to the pit with worms for further composting. The harvested vermicompost is stored in dark, cool place. It should have minimum 40% moisture. Sunlight should not fall over the composted material. It will lead to loss of moisture and nutrient content. After that packing can be done at the time of selling. If it is stored in open place, periodical sprinkling of water may be done to maintain moisture level and also to maintain beneficial microbial population.
In order to produce the commercial level vermicompost, a standardised set of technologies for construction of vermicompost is being used. Vermicompost units are constructed according to the need of vermicompost. Bricks, cement, stones, iron sheets, sand and iron angles are needed to make the vermicompost units. Vermicomposting processing is completed in 50-60 days when raw material is completely decomposed and it looks black or dark brown and granular. Watering should be stopped as compost gets ready. The vermicompost is sieved, bagged and sold or utilized as per need. The earthworms are reused and they can also be sold. For composting the species such as Eisenia fetida and Eudrilus eugenae are used which are efficient to maintain vermicomposting process. Eisenia fetida can tolerate wide range of temperature tolerance and has a very high reproductive potential. Earthworms can be collected from Talawara village in Reasi distt. of J&K.Standardized procedure on sound scientific basis of vermicompost production and construction of unit can be followed by the famers in their field. After harvesting of the vermicompost on 50-60 days and after earthworm inoculation, the analysis of the compost can be completed in the lab by the researcher. After that it can be applied in the farmers’ field according to the nutrient percentage. Analysis of vermicompost samples shows higher levels of available nitrogen (N), phosphorus (P) and potash (K) as compared to the conventional compost samples made from similar feedstock. It maintains moisture in the soil and can significantly reduce the demand for irrigation by nearly 30- 40%.The crops sown with the application of vermicompost are least affected by the insects-pests and diseases.
Keeping the scope of organic farming in view, there is need to popularize the vermicompost on large scale. Vermicomposting can help to increase area under organic farming and thus can help in the production of safe food for the mankind. It can reduce the cost of cultivation and can also improve the crop yield and prodcutivity. Vermicompost improves soil structure, texture, aeration, and water holding capacity and prevents soil erosion. Vermicompost helps to protect the environment by reducing the use of chemical fertilizers. Studies indicate that 10,000 worms in a farm plot provides the same benefit as three farmers working for 8 hours in shift round the year with 10 tons of manure applied in the plot. Vermicompost is rich in beneficial micro flora such as fixers, P- solubilizers, cellulose decomposing micro-flora etc.Vermicompost helps to raise the socio-economic status of the farmers by reducing their cost of cultivation and reducing their dependency on inorganic fertilizers. It also prevents nutrient losses from the soil. Generally vermicompost is free from pathogens, toxic elements, weed seeds etc. and thus it minimizes the incidence of insect-pests and diseases. It can be adopted as an enterprise. It can be effectively used in the climate smart agriculture and can be a boon for the organic farmers. Vermicompost provides the best answer for ecological agriculture.
(The writer is Sr. Scientist and Head of KVK, Reasi, SKUAST-J).
