Chennaiites seem to have ushered in the new year with a green enthusiasm. While many have either ditched or are in the process of discarding the use of plastic, a lot of them too have been looking for other environment-friendly methods that they can adopt. Composting seems to be at the top of that list as DT Next has found out.
According to MB Nirmal, founder of an NGO Exnora which focuses on environment, there are at least 35 methods, but the factors that determine the best method to begin composting are space, time and money. He says, “In flats and apartments, the common complaint is that there is no space available for the procedure. But, one can easily begin create their compost bin by placing two earthen pots — one on top of the other.”
Composting can broadly be divided into three categories — aerobic and anaerobic. While aerobic composting relies on air and occurs above the ground, all it requires is a bin with aeration holes, anaerobic is without oxygen and works under the ground in the form of trenches.
There are composting techniques that have gained popularity over a period of time like the khambas that are touted to be the best bet for households, taking care of the space constraints.
The earthen wares used to decompose kitchen waste works on a simple balance technique between wet and dry waste. Navneeth Raghavan, an environment enthusiast who has been promoting various composting techniques, says, “The whole trick is to balance the moisture and accordingly add the remix powder as dry waste.
Sometimes, the waste generated in the kitchen can have more water — say for example watermelons or squishy tomatoes. For about 750 grams to 1 kilogram of wet waste, a handful of dry waste which has necessary microbes to break down the organic waste. You can be assured that there is no odour or mess.”
In a three-pot khamba set up, once the top one gets filled, it can be exchanged with the second one and then the third.
For a group of apartments or flats, the aagas set up works wonders, says Navneeth who has helped temples like Kalikambal Temple in Parrys set up composting units on their premises. Aagas comprising 550 litres each can be bought in pairs, “These can take care of the waste generated in 20 households and if there are more households you can buy more pairs accordingly.
Once a week, the mix is sprinkled with coco peat or lab developed bacteria microbe (three spoons diluted in water). “When one container gets filled up in the pair, the other is used and by three months you have the manure ready. In fact, at the Kalikambal Temple there are these lemon offerings that land in the aagas and the resultant manure is a fragrant mix that can be used in household gardens,” adds Navneeth.
In fact, a few similar initiatives in temples and other communities have provided a source of income for the maintenance staff, who sell the manure and make money from it.
A Japanese and anaerobic process method of composting, Nirmal calls it a simple method that is appropriate for households. In Bokashi composting, kitchen scraps of all kinds — including meat and dairy products banned from aerobic systems — are mixed with some of the inoculated bran, pressed into the Bokashi bucket, covered with another handful of bran, and tightly covered. When the bucket is full, it is sealed shut and set aside for three weeks. Every other day during that time, the leachate — a nutrient-rich liquid that is an inevitable byproduct of anaerobic composting — needs to be drawn off. So, it would be an advantage if this kind of composting is carried out in a container with a tap at the bottom.
“You can add bran as an agent to break down the waste,” Nirmal points out. The method also involves using a tap in the lower container, as there are two containers used—one kept tightly inside the other. The tap can be used to remove the acidic residue from the wet waste that can be used for plants. After three weeks, the organic waste is mixed with manure and after five weeks it is decomposed entirely.
The Tamil Nadu Agriculture University in Tirur has been conducting classes in vermicomposting for the general public. Dr P Yogameenakshi of the University explains, “Vermicompost is nothing but the excreta of earthworms, which is rich in humus and nutrients. We can rear earthworms artificially in a brick tank or near the stem or trunk of trees (especially horticultural trees). By feeding these earthworms with biomass and watching properly the food (bio-mass) of earthworms, we can produce the required quantities of vermicompost.”
She explains the phases of the procedure. “Processing involving collection of waste, shredding, mechanical separation of the metal, glass and ceramics and storage of organic wastes. Pre-digestion of organic waste for twenty days by heaping the material along with cattle dung slurry. This process partially digests the material and makes it fit for the earthworm to consume. Cattle dung and biogas slurry may be used after drying. Wet dung should not be used for this process.”
It is also important to maintain a balance of the waste added in vermicompost bins as if the waste becomes too acidic, it can kill the worms.
Speaking about the process to prepare a base for the earthworms, Yogameenakshi says, “You need a concrete base to put in the waste and for the earthworm bed.” After preparing the bed, organic waste or pre-digested organic waste is added to the container before adding the worms.”
At the end, the compost must resemble a dark and crumbly matter which needs to be sieved before it is used in gardening. Partially decomposed materials can be returned to the container, says the professor. The vermicompost must be stored in a proper place to retain moisture and allow the beneficial micro-organisms to stay alive, she points out.
- It reduces waste that reaches landfills
- Almost 70 per cent of your kitchen waste can be composted
- It provides the best manure that can be used for growing plants
A simple DIY composting set up by NGO Exnora
Materials needed: 2 earthen pots, soil and organic waste
Steps: Mount one earthen pot above the other. Deposit a layer of organic waste and top it with soil. If it is non-vegetarian waste, cover it with a thicker layer of soil.
Once the top earthen pot is full, move the lower one to the top. In 90 days, the manure will be ready. Remember to cut peels into smaller pieces for quicker composting.
Tips for successful composting
Add activators to kick-start decomposition
‘Activators’ can be added to your compost to help kick-start decomposition and speed up the process. Common activators include: leaves, grass clippings, young weeds and well-rotted chicken manure.
Flying insects attracted to your compost?
Fruit flies are naturally attracted to the compost pile. Prevent them by covering exposed fruit or vegetable waste. Keep a small pile of grass clippings next to your compost bin and when you add new kitchen waste to the pile cover it with one or two inches of clippings. Adding lime or calcium will also discourage flies
Unpleasant odour from your compost pile?
This can be a concern in urban and suburban areas with small lots and neighbours living close by. Reduce or eliminate odour by following two methods: first, remember to not put bones or meat scraps into the compost; second, cover new additions to the compost pile with dry grass clippings or similar mulch. Adding lime or calcium will also neutralise odour. If the compost smells like ammonia add carbon-rich elements such as straw, peat moss or dried leaves.
Is your compost pile steaming?
No problem. A hot, steamy pile means that you have a large community of microscopic critters working away at making compost.
Is your compost pile soggy?
This is a common problem, especially during winter, when carbon-based materials are in short supply. To solve this problem, you’ll need to restore your compost to a healthy nitrogen-carbon balance.
Pointers for beginners
- The secret to a healthy compost pile is a perfect ratio between carbon and nitrogen
- Carbon-rich matter (like branches, stems, dried leaves, peels, bits of wood, sawdust pellets, shredded paper, corn stalks, coffee filters, egg shells, straw, peat moss, wood ash) gives compost its light, fluffy body
- Nitrogen or protein-rich matter (manure, food scrap, vegetable and fruit peels, and green leaves) provides raw materials for making enzymes
- A healthy compost pile should have one-third green and two-thirds brown materials
- Do not compost meat, bones, or fish scraps (they will attract pests) unless you are using a composter designed specifically for this purpose If you are adding garden waste into the compost, avoid adding perennial weeds or diseased plants