Composting Organic Waste from Kitchen and Garden for a Free Natural Fertilizer

Around 60% to 70% wet waste produced daily in cities like Bangalore and Mumbai is wet waste or organic, biodegradable waste. 

It is extremely illogical for this waste to be dumped into landfills if it can be treated at home or in the backyard. Not only does it reduce the pressure on landfills, but also proves to be profitable to societies and individuals. 

Composting helps to dispose off wet waste in a productive way, creating sustainable gardens, and also provides the opportunity for societies to generate extra income by the sale of compost fertilizer. It enriches the soil quality, helping it retain moisture and reduces the waste volume handed over to the government, which is already struggling pitiably to process India’s phenomenal waste generation (1.50 lakh metric tonnes daily).

Most people are repelled by the idea of composting because they’re uninformed and present arguments like, ‘compost smells’, ‘composting is messy’, ‘it takes too long to compost anything’. All of these facts are right if composting is done improperly without the right initiation. Let’s get right to it. 

What is organic waste?

It’s biodegradable (green waste) natural waste materials (from plants and animals) that can be broken down into simpler components, carbon dioxide, methane, water, by natural processes such as composting, aerobic/ anaerobic digestion. 

What is composting?

When the organic waste is decomposed, treated and recycled to create nutrient-rich soil fertilizer and conditioner, it’s called composting. It’s natural and biological.

What is considered organic waste?

Nitrogen rich waste (green waste)

  • Cooked and uncooked food/leftovers (including crushed eggshells)
  • Vegetable/fruit skin, seeds, dry snacks, grains, bread crumbs, dairy products
  • Juice, old wine, fruit core
  • Coffee grounds, used tea powder and tea bags

Carbon rich waste (brown waste)

  • Used paper plates/cups, food-soiled paper (excluding Styrofoam), egg cartons
  • Paper towels and tissues
  • Grass clippings, leaves, dried flowers, grass, cut flowers, weeds
  • Cardboard boxes, unpainted non-treated wood and plywood, sawdust, old notebooks (plastic free)
  • Dry cat/dog food

Main types of ‘at home composting’

Vermicomposting means decomposing waste by using earthworms (red wigglers and red worms). It is richer in nutrients and composts faster than regular hot composting, which is done in bigger containers under the sun. Aerobic composting is traditional composting in the presence of microorganisms exposed to air. Composting tools include bins, tumblers and countertop electric composters. 

Easiest DIY way of composting at home

There should be a Carbon: Nitrogen ratio of 30:1 in your compost, three parts brown waste to one part green waste. 

  1. Pick a medium-sized earthen or plastic container and drill 5-6 holes on the sides (more if the container is bigger).
  2. Place newspapers and cardboard under the container to contain any seepage.
  3. Line the bottom of the container with soil or shredded newspaper.
  4. Start adding alternate layers of green waste and brown waste. You can also introduce half composted materials like buttermilk or cow dung to kickstart the process.
  5. Cover the top with plastic, cloth or wooden planks.
  6. Depending on the aeration and the type of waste, your compost will be ready when it turns into a thick, dark brown, earthy-smelling sludge.

The pile shouldn’t be too hot or cold and properly aerated. It usually takes two months for the above listed process to produce completely ready compost. You should turn the compost pile every 4-7 days. Use a trowel to dig into the lower layers where you should add fresh piles of green/brown waste. When the pile shrinks to half the size and the waste is unrecognisable, your compost is ready.

The Don’ts of composting at home

  • Do not use meat, bones, fatty foods, grease, seed producing weeds and dairy. They take longer to break and attract flies.
  • Don’t add pet feces and diseased garden plants.
  • Do not use compost bins as a place to dump green waste haphazardly. This is a curated process.
  • Do not add big chunks. Cut down all waste into smaller pieces.
  • Do not throw away wet waste not fitting in the pile. Maintain multiple compost bins at the same time.

Community composting

Societies of today understand that waste is an asset, not an inconvenience. The scope of community composting starts from backyard composting in housing societies but can extend to entire neighborhoods and town/city communities, entailing, closed-loop (for society only) as well as commercial and scalable initiatives. From maintaining worm farms to static pile composting, from Bokashi method to turned windrow style, or just simple in-vessel composting, the options are diverse. Green living, cleanliness drives, resource stewardship, and eco friendly waste management education and installations have been the tell-tale characteristics of active and mindful communities. 

A society can start with a manually operated outdoor composters placed inside its garden or invest in an Organic Waste Converter (OWC). Let’s explore both ideas.

While we understand that open pile composting may not be the ideal way to compost due to  space constraints in residential societies, in-vessel composting can be less of a hassle.

Compost tumblers are barrels on stands (or round bins with no assembly) and require 5-6 spins every couple of days or a daily roll each day, depending on the model. You’ll have models with the option of dual chambers for different stages of decomposition and an outlet for compost tea (liquid fertilizer from active compost pile). The C:N ratio of what goes inside still applies (as per the user manual). Prices range from Rs 5000-Rs 13,000 per unit. You’ll need to buy a few based on the number of apartments, the quantity of waste they generate and also train the gardener/other service staff in the entire process. These options are for small societies that don’t produce too much waste on the daily. The turnaround time for compost tumblers is four to six weeks if the mix is right. But it’s a highly affordable option for housing societies. Even ten tumblers can get you decent results for 200 apartment units.

Organic waste converter (OWC):

For societies that don’t prefer manual composting and have no space for compost piles and multiple tumblers, there’s the alternative to use fully automatic organic waste converters. They produce compost in 24 hours and can deal with large quantities of wet waste generated daily. Models can range from processing power of 5 to 10 batches daily with a capacity of 25-100 kg waste. Manual converters take at least 15 days to produce the same results. A good quality electric OWC can cost between Rs 3.5 lakh to Rs 4.5 lakh and above. Semi automatic machines could cost between Rs 1.5 to Rs 2 lakh. 

Tax benefits on compost wet waste produced by Housing society

Housing societies that produce over 100 kg of waste and have an area of 20,000 sq meters are required not only to segregate dry and wet waste but also do on-site disposal. In cities like Mumbai, the government is offering a 3% property tax rebate to housing societies that compost wet waste and up to 7% rebate if a society gives zero garbage to BMC. Such heavy incentivisation could become the norm across the country if citizens actively participate in waste management self-starter initiatives. Other than that, there’s always a little profit to be made by selling organic compost in farmers markets or even online. Eventually, the OWC would pay for itself.

What do you think?