Reports show that 62 million tonnes of waste are produced in India every year, 50% of which is organic waste. According to the Food and Agricultural Organisation, nearly 40% of the food produced every year is thrown away. This waste finds its way into the ever-increasing mounds of garbage known as landfills.
Organic waste is simply any refuse that is biodegradable- food waste, paper waste, manure. If biodegradable means that the waste will decompose on its own, then why are the aforementioned figures a matter of concern?
Although organic waste decomposes on its own, the decay itself takes place through an anaerobic process that leads to the creation of methane and other greenhouse gases. Methane absorbs 30 times more heat than carbon dioxide, and is also known to cause respiratory problems. Being at the threshold of climate disaster, an alternative waste management technique is a dire requirement. This is where vermicomposting steps in.
Vermicomposting is the process by which earthworms consume organic waste and excrete it in the form of a nutrient-rich fertilizer. These excreta, called vermicast, proves to be remarkable plant food and an effective use of kitchen garbage.
Although the importance of earthworms in agriculture had been emphasized throughout history by the likes of Aristotle, Cleopatra and Darwin, the first person to actively implement this process was Mary Applehof, a biology teacher from the United States. She bought around 400 grams red wriggler worms to continue growing her vegetable garden during winters, and by the end of the season they had consumed 29 kg waste from her kitchen.
In her book titled “Worms eat my garbage”, Applehof describes the process as, “very simple and has obvious advantages in addition to increasing garden yields.” The worms require an initial input of food and bedding and an adequate measure of moisture, temperature, pH and darkness, after which they deliver without demanding much care and attention. All plant-based organic waste can be added to the compost bin, although acidic fruits and vegetables like lemons are not recommended as they can harm the worms. Vermicomposting is gradually being adopted as a domestic practice because of its ability to provide a solution for chemical fertilisers and waste disposal at a low cost.
Besides being an effective household strategy, vermicompost also plays a major role in improving agriculture. Compared to topsoil, vermicompost contains seven times more potash and five times more nitrogen in readily available form, enhancing the uptake of nutrients by plants without harming them. The humus present in the vermicast increases the water retention capacity of the soil and aids shoot and root growth. It is also known to stimulate seed germination in crops like tomato, petunia, green gram and pine trees. Plants growing in vermicompost produce three times greater yield. Antibiotics present in the worm excreta increase the biological resistance of plants against hard-bodied pests and diseases such as root rot, thus reducing the demand for chemical fertilisers. Moreover, these worms multiply at a rapid rate, doubling in size every 2 months, which allows for large-scale composting at a low investment.
Recent years have witnessed an increasing interest in this issue. The Organic Centre of Canada is experimenting on cold-climate vermicomposting and a vermicompost industry is thriving in Australia and New Zealand, with extensive research and the use of both home worm bins as well as large-scale composting. Clives Edward, an entomologist from Ohio State University, wrote about the potential of larger vermicomposting structures developed by English engineers: “The methods they designed ranged from relatively low technology systems using manual loading and waste collection systems, to large, completely automated and hydraulically-driven continuous flow reactors”
Closer home, vermicomposting is gaining increasing popularity as an environmentally sustainable method to tackle the problem of safe waste disposal and meet the demand for sustainable agricultural production. The Green Revolution of the 1960s had caused a heavy increase in the use of chemical fertilisers produced from the depleting resources of the planet, to boost crop production at the cost of soil fertility and human health. Vermicomposting provides a sustainable and economical alternative that allows for huge quantities of waste to be converted into nutritive organic plant fertiliser, thereby also reducing the air pollution caused by burning of farm waste. National provisions like the Cent Vermicompost Scheme as well as subsidies by the regional governments play a major role in promoting the practice.
Vermicomposting, when adopted across the nation, can bring about a revolution in India in numerous areas – community waste management, highly sustainable and economical method of crop production, and poverty eradication in the rural regions. As in Darwin’s words, “Worms are more powerful than the African elephant and more important to the economy than the cow.”
