The simplest way to make good compost at home is a covered heap or pit of dry "brown" material (straw, dry leaves) mixed with moist "green" material (kitchen scraps, green leaves, a little dung), kept damp like a squeezed sponge and turned every 1-2 weeks; it is ready in about 2-3 months. If you have little space, a worm bin gives finished castings in about 6-8 weeks, and a sealed bokashi bucket suits a flat.
This page compares the four home-scale methods, gives the recipe and numbers, and shows how to fix the usual problems (smell, flies, dry heap) and how much to use. If you want to sell vermicompost as a business, go to vermicompost making and business.
Which method should you use
| Method | Best for | Time to ready | Main trade-off |
|---|---|---|---|
| Aerobic heap or pit (hot composting) | Farm or house with a yard; crop residues, dung, leaves | About 2-3 months with turning | Needs turning and water, and a pile at least about 1 m across to get hot |
| NADEP brick tank | Farm-scale, 2.5 tonnes at a time | 90-120 days | Initial brick tank and a lot of material at once |
| Worm bin (vermicompost) | Kitchen waste, small gardens, terraces | About 6-8 weeks per batch in a small bin | Worms dislike extremes and some foods; output is small |
| Bokashi bucket | Flats with no space, cooked food and dairy | 2-3 weeks to ferment, then bury or add to soil | Needs bokashi bran, and the result is pre-compost, not finished compost |
Method 1: hot compost heap or pit
Research on composting agrees on the main numbers: a starting carbon-to-nitrogen ratio of about 25:1 to 30:1, moisture of about 40-60% (a wrung-out sponge), and a pile of at least about 3 ft × 3 ft × 3 ft (roughly 1 m cube) so that microbes can heat the pile to about 55-65°C, which kills most weed seeds and pathogens. In practice:
- Collect: browns (dry leaves, paddy or wheat straw, sawdust, dry grass, cardboard) are high in carbon; greens (vegetable peels, fresh weeds, green leaves, fresh cow dung, poultry droppings) are high in nitrogen. As a rule of thumb, use about 2-3 parts dry material to 1 part fresh green by volume (adjust to your smell and heat).
- Chop stalks and large pieces to 2-5 cm so they break down faster.
- Layer 15-20 cm of browns, a thin layer of greens and a sprinkle of dung water or old compost, repeating to a height of 1-1.5 m. Sprinkle water as you go until the material is damp but not dripping.
- Cover with straw, gunny or a sheet so the pile does not dry in the sun or soak in the rain, and site it in shade.
- Turn after 1-2 weeks when it cools, moving the outside to the centre, and again every 1-2 weeks. Add water if dry.
- Finish: when the pile no longer heats up after turning, the material is dark brown, crumbly and smells of earth, let it cure for 2-4 weeks.
Method 2: NADEP tank
The NADEP method, developed in Maharashtra by N. D. Pandharipande, uses a brick tank 12 ft × 5 ft × 3 ft with alternate bricks left out as vents above about 1 ft from the ground. Reported inputs for one tank are roughly 1,350-1,400 kg of dry and green farm waste, about 100 kg of dung or biogas slurry, about 1,650-1,700 kg of fine sieved soil and about 1,350-1,400 litres of water, filled in layers within 24 hours (not beyond 48 hours), topped up after 15-30 days as the heap settles and moistened every 6-15 days. One tank gives about 2.5 tonnes of compost in 90-120 days, and because it is closed, it loses less moisture and smells less than an open heap.
Method 3: worm bin for kitchen waste
- Use a pot, crate, tub or cement ring with drainage holes, kept in shade at about 20-30°C.
- Spread 5-8 cm of bedding (coconut coir, dry leaves, shredded paper or partly rotted dung) and moisten it.
- Add earthworms (Eisenia fetida is the common species). Start with about a handful to a kilogram depending on bin size, and feed small amounts of chopped vegetable waste, burying it under bedding.
- Never add fresh hot dung, onion, garlic, citrus, oil, meat or salty food. Keep the top covered with gunny.
- Harvest after 6-8 weeks (or as the bin fills): move the finished material to one side, put fresh feed on the other, and let worms cross over before scooping.
FAO's on-farm composting notes put vermicomposting at about one month in Indian conditions and warn that worms are harmed above about 35°C, so keep the bin out of direct sun.
Method 4: bokashi for flats
A sealed bucket with a tap uses bokashi bran to ferment kitchen waste, including cooked food and small amounts of dairy. Add scraps in layers with about a tablespoon of bran per 500 g of waste, press out air, keep it airtight, drain the liquid every 2-3 days (dilute it before watering plants), and leave it 2-3 weeks. It should smell sour like pickle, not rotten. Then bury it in soil or add it to a compost heap or worm bin to finish.
Troubleshooting
| Problem | Likely cause | Fix |
|---|---|---|
| Bad rotten or ammonia smell | Too wet or too many greens, not enough air | Mix in dry straw or leaves, turn the pile |
| Pile stays cold and nothing happens | Too dry, too small or too much carbon | Add water and fresh greens or dung, and make the pile larger |
| Flies and maggots | Exposed kitchen scraps | Bury scraps under 10 cm of browns and cover |
| Ants | Pile too dry | Moisten and turn |
| Worms trying to leave the bin | Too wet, acidic, too hot or fresh dung added | Add dry bedding, drain, shade it, remove fresh feed |
| Weeds sprout in the finished compost | Pile did not get hot enough | Re-heap with more greens and turn again; cure longer |
Is it ready and how much to use
- Ready compost is dark, crumbly, smells of earth and is no longer hot. Finished compost settles at a C:N ratio of about 10:1 to 15:1. A quick germination test: fill a cup with a half-and-half mix of compost and soil, sow 10 moong or cress seeds, and if nearly all sprout in a few days, the compost is mature.
- Pots and kitchen garden: mix about one part compost with 3-4 parts soil, or top-dress 1-2 handfuls per plant.
- Field crops: state package-of-practice guides commonly recommend FYM or compost at about 5-10 tonnes per hectare (2-4 tonnes per acre) and vermicompost at about 2.5-5 tonnes per hectare; check your crop recommendation with the KVK. Compost does not replace a soil-test-based fertilizer plan; see Soil Health Card and fertilizers.
- Compost saves money by cutting the amount of purchased fertilizer you need over the years and by improving water holding; it is a slow soil builder, not an instant nutrient source.
For a bigger shift to chemical-free farming, see how to start organic farming and natural farming methods.