INTRODUCTION

Dumps of organic waste piled on barren lands are a regular sight around our city outskirts. According to a CIPS-ASCI study on waste management, the top eight cities in India generate an average of 4,500 tons of solid waste every day or 36,500 tons in total. This figure excludes the uncollected waste and sewage water that flows down our rivers! These create environmental hazards. However, recycling processes can filter these waste materials into usable items benefiting our environment and society. Vermicomposting is the most eco-friendly recycling process to reduce organic waste. This recycling process not only converts organic debris into high quality compost but the chemical changes that the debris undergoes make the nutrients easily available to the plants. Vermicomposting also can reduce heavy metals and toxins found in sewage slush. It has also been found that vermicomposting helps to significantly reduce the presence of pathogens in organic matter. Vermicomposting is a simple biotechnological process of composting, in which certain species of earthworms are used to enhance the process of waste conversion and produce a better end product. Two types of earthworms are recommended for this, they are: the Red Wiggler or manure worm (Eisensia foetida), and the Red Worm, another manure worm (Lumbricus Rebellus) are cultivated in agricultural farms to consume organic waste including all kinds of biodegradable wastes. They then give out the excreta, which is known as ‘vermi-cast’. These vermi-castings are rich in nitrate and contain minerals like phosphorous, potassium, calcium, and magnesium, which are excellent fertilizers and soil conditioners. Vermicomposting differs from composting in several ways. It is mesophilic process, utilizing microorganisms and earthworms that are active at 10-32°C (not ambient temperature but temperature within the pile of moist organic material). The process is faster than composting; some of the advantages of vermicomposting over regular composting are that vermicomposting can be done indoors with relatively no negative effects, it is faster than regular composting, and it produces and overall better compost. A study showed that traditional composting it associated with elevated temperatures within the pile due to microbial activity. These high temperatures actually slow the composting process. Vermicomposting produces little heat which does not slow the composting process. Vermicompost is the excreta of earthworm, which are capable of improving soil health and nutrient status. Vermiculture is a process by which all types of biodegradable wastes such as farm wastes, kitchen wastes, market wastes, bio-wastes of agro based industries, livestock wastes etc. are converted while passing through the worm-gut to nutrient rich vermicompost. Vermi worms are used here act as biological agents to consume those wastes and to deposit excreta in the process called vermicompost. In short, earthworms, through a type of biological alchemy, are capable of transforming garbage into ‘gold’.

HISTORY OF VERMICOMPOSITING

The Egyptians were one of the first cultures to recognize the soil amending properties of the earthworm. Under Cleopatra’s rule, the removal of earthworms from Egypt was a crime that could have one killed. Worms have been observed by such scholars as Aristotle and Charles Darwin as organisms that decompose organic matter into rich humus or compost. It is believed that the mother of modern day vermiculture is Mary Appelhof. As a Michigan biology teacher, Appelhof wanted to continue composting in winter months even though she lived in a northern climate. She ordered worms from a bait shop nearby and set up one of the first indoor composting systems. She found her composting system to be a great success. She published two brochures titled “Basement Worm Bins Produce Potting Soil and Reduce Garbage” and “Composting your Garbage with Worms”. Her work was featured in a New York Times titled “Urban Composting: A New Can of Worms”. This inspired many people to partake in vermiculture, especially urban apartment dwellers.

VERMICOMPOSTING PROCESS

The vermicomposting process can be carried out not only in large-scale agricultural farms, but also at our own homes to make organic manure for our kitchen garden. The basic requirements for vermicomposting to start are: • All the organic waste that one can collect – dry leaves, fruit peels, rotten vegetables, stale food, etc. • A deep container made up of either wood or plastic to store waste materials • Red wiggler earthworms, which are widely used since they voraciously eat up all types of organic matter • Any biodegradable material that is high on carbon content to serve as bedding for the earthworms to live on as well as to keep the worm container moist. Shredded cardboard paper, office paper, any paper towel, newspaper and coir fibers are often used as bedding. Before putting the bedding into the container, it needs to be hydrated with water for at least a day such that it retains the moisture. However, the excess water has to be squeezed out before it is put inside the container. As it is essential to use appropriate species of earthworms for culturing, it is necessary to follow certain procedures for treatment of the material to be used as substrate and feed for earthworms. It is essential in the tropical countries to maintain the optimum temperature in the organic matter between 25º and 30º C and moisture level ranging from 40 -60%. Any kind of agricultural residue along with cow-dung forms the major resource component for vermicomposting. In India, vermiculture is practiced mainly The ABCs of Agriculture Tanweer and Abrar 97 for recycling of organic wastes. The awareness created among the farming community, regarding the imbalance created in the nutrient status of soil, has led them to adopt technologies to augment the breakdown of organic residues and return them to soil (Kale, 1994). In this process, different kinds of organic residues like hedge trimmings, weeds, litter, hey, husk and animal excreta that are available in the farms are used for vermiculture. The collected residues from farm activities along with cow dung is normally piled up on the ground surface and watered to maintain 40- 60% moisture. This mix is turned two to three times in two weeks to provide aeration and for exposing the entire material to thermophillic phase. By the end of three to four weeks, material is ready to be used as substrate and feed for epigeic earthworms. Bright sunshine and unpredictable rains are the common features in India. During dry seasons, lack of regular food in the vicinity forces rodents and other predatory mammals to find alternative and easily reachable food source. It is advisable to practice vermicomposting in sheltered, protected conditions to avoid these problems. The tanks could be built depending on the availability of construction materials like cement blocks, bricks, granite slabs or bamboo poles. The length of the tanks can vary based on the availability of raw materials in the farm. The breadth and the height should be preferably 1.2 and 0.9 meters. A temporary thatched roof protects the tanks from inundation during heavy rains. Earthworms that are identified for culturing are released on the surface layer. This enables them to feed on the organic material from surface to the base of the tank. As they start feeding, they release the castings on the surface. It will be easy to collect the casting periodically without disturbing earthworms. This method of making earthworms to work from surface to downwards is more suitable in tropical conditions, where there may be chances for unexpected raise in temperature in the organic matter. Vermicompost collected periodically will have cocoons and small earthworms. When small cow-dung balls of about 10cms in diameter are buried in the collected vermicompost at random and left for a period of ten to fifteen days, earthworms that hatch out of cocoons get attracted to these cow-dong balls. Thus, without much labour, earthworms can be separated from vermicompost.