The heap composting method is a very simple and is quite popular in Bhutan.
Materials Required
1. Green biomass – 1 ton
2. Dry Biomass – 1 ton
3. Cow dung – 200 kg
4. Water
Method
1. Demark an area 2 metres width and 3 metres length. Depending on the availability of the materials the length of the heap can be extended.
2. A layer of stones or wooden logs are placed within the demarked area as a basal layer which helps in providing aeration.
3. Dung slurry is prepared by mixing 25 kg of dung in 100 liters of water.
4. A layer of dry biomass is uniformly spread to the height of 30 cms and moistened with dung slurry.
5. On the top of the dry biomass layer, green biomass is spread and moistened with dung slurry.
6. Similarly, alternate layers of dry and green biomass are laid to the height of about 1-1.5 metres height. Each layer of biomass is thoroughly moistened with dung slurry.
7. Similarly, alternate layers of dry and green biomass are laid to the height ofabout 1-1.5 metres height. Each layer of biomass is thoroughly moistenedwith dung slurry.
8. When the heap has reached a desired height it is covered with soil or straw.
9. To prevent the loss of nutrients by volatilization, the heap is made in shade. In certain places wherein there is no natural shade, thatched roofs or shade nets are to be made available.
10. To hasten the process of composting the heap can be turned after a month.
11. Depending on the weather conditions the compost will be ready in 2-3 months. In warm weather the composting process is faster than in winter months.
