As organic matter acts as both the substrate and food in vermicomposting, and soil is not involved, only earthworms can be used in vermiculture.The growth of industries,urban cities and the ever increasing human population have led to an increased accumulation of waste materials.Waste materials introduced into the environment are of two types namely non-degradablr and degradable wastes.The disposal of these solid wastes remains serious challenge in most of the countries.
In recent years vermiculture has received much attention in many countries.The spiralling cost of fish meal and the low supply of soyabean meal are responsible for the utilization of earthworms as an alternative low cast protein meal in aquaculture and poultry industry.Further the worms also play an important role in waste disposal.They decompose natural organic wastes into rich compost fertilizer.A single earthworm can produce 1000-1500 offsprings in a year.2000 mature breeders can produce more than 1 million worms.
Culture of earthworms
The method of culturing earthworms can vary from place to place.A cultured worm must be able to adapt to substrates,grow fast and breed or multiply readily under controlled conditions.
A compost pile bed of 2.4 m long,1.2m wide and 0.6m deep appears to be very satisfactory for a population of more than 50,000 earthworms.The boxes can be made from wood to accommodate 5000 to 6000 worms.Soil, organic matter,manure,leaves,rice straw,dried water hyacinth,saw dust and any fermented substrate can be used as a culture medium to raise worms in boxes or containers.The worms in the worm beds can grow and reproduce faster if they are given sufficient food.Any decayed organic matter appears to be good food for worms but the feed should not be contaminated by detergents or insecticides.
Since the earthworms are rich in protein,fat, carbohydrate and Ash they are used as a feed component for fish,prawn and shrimp.They are also used as livestock feed in poultry industry.
Many species of earthworms are easily adapted to agricultural wastes like after harvest strubble, sugarcane thrash,coir waste,dung of cow,horse,sheep and poultry droppings.The breakdown of these materials or the degrades of organic matter by worm activity is called ‘vermicompost’.It is a better source of organic manure.