Composting - Square Compost Method - Japan - ARI
by the Asian Rural Institute
page developed by Emma Marks, ARI intern from Wilmington College
submitted August 2019
There are many different ways to make good compost.
One strategy used at ARI is call
A. Choose a place to make compost
Choose a place in the sun, out of the wind, near a source of water and materials. Wind and rain remove nutrients from the compost.
If there is a place that has a roof and cement floor, it is very nice. However, it is good enough to make compost on the ground and cover it with a blanket.
B. Collecting materials
Wet materials (low C/N materials) (6 parts)
Dry materials (high C/N materials) (3 parts)
In this example, our wet material was biogas liquid made from pig manure. Our dry material was green weeds that we harvested from around our fields.
C. Making the frame
The frame should be constructed of a solid material. We used a 1.5mx1.5m square of wood.
You will also need a supporting post for the middle. We used bamboo.
D. Cutting materials
Prepare the plant materials by cutting them into small pieces.
It is much easier for micro-organisms to decompose small pieces.
E. Piling materials
Pile a layer of dry materials in the frame, then add wet materials.
After that add water.
For our example, we added a small amount of IMO3 (about 1 handful) to each layer to speed up decomposition. We also did not add water because the biogas liquid is wet. If you use a dried manure, you can add water.
Pile dry materials, wet materials and rice bran again. Then place a post for aeration.
Walk (or dance!) on the pile to compact the materials.
Moving up frame and more piling
When the frame is full of compacted materials, slide it up and repeat piling materials and compacting until it reaches 1.5 - 2.0m.
Sliding the frame upward
Walking on the pile to compact it
You can seal the top of the pile with 1.5 cm of fertile soil and remove the central post.
Cover the pile with a blanket.
Why cover compost
To avoid direct sunlight (micro-organisms are weak against UV rays.)
To keep moisture
To keep the temperature
To avoid rain
After one day the temperature should be between 40-50°C.
After two days it should be 60-75°C.
This temperature continues for 3-10 days.
In this period most diseases and eggs of harmful insects are killed by the heat.
After 10-14 days, the compost lacks oxygen and water, so it is necessary to turn it.
The second turning is after 10-14 days.
The third turning is after another 10-14 days.
After the third turning, the temperature becomes 40-50°C.
After 2 weeks, it should drop to 30°C.
This is the last stage of fermentation.
Why turn compost
To supply air for micro-organisms
To equalize different kinds of materials
To crush materials
To cool down high temperature
To promote fermentation but not rot
L. Management of water
Before fermentation 50% of water is needed. And then 60%.
If water content is less than 40%, the compost ferments very slowly.
When turning compost, it is necessary to adjust the water content of the compost.
Organic Farming - Soil Fertility