A maize field, with children standing beside it

Rice husks for better soil

Rice husks for better soil: a treated surface turns them into a material that builds soil

We turn rice husks into a material that builds farm soil. With a soil improver made from treated rice husks, we confirmed faster germination and growth of radishes in Hiroshima Prefecture. It is also in use at a farm in Takehara, Hiroshima Prefecture.

For farmers, JA agricultural cooperatives and local governments

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The problem

Grow the same crop in the same field year after year, and it can start to do poorly, a problem known as continuous cropping injury. Meanwhile, rice growing leaves large amounts of husks every year, and left as they are, husks are slow to return to the soil.

Maize growing in a field
Takehara, Hiroshima Prefecture (August 2026)

What we do

We treat the surface of rice husks and settle three kinds of microbes on them, among them the bacterium used to make natto, a fermented soybean food. The soil improver that results is spread on fields.

How the treatment works

Where things stand, and what to know

  • Allow about six months from spreading it on a field to starting the first crop.
  • Stage: Concept, We are also considering its use on abandoned farmland and salt-damaged fields.

Stage and evidence

Each claim carries its own stage, and who confirmed it where that is on record.

Rice husks for better soil

We treat the surface of rice husks and settle useful microbes on them, turning the husks into a soil improver for building up farm soil.

  • Stage: Proven, Our own work

    With a soil improver made from treated rice husks, we confirmed faster germination and growth of radishes in Hiroshima Prefecture.

  • Stage: Proven, Our own work

    The first crop can be started about six months after the soil improver is spread on a field. It takes a year for the husks to return to the soil and for the microbes to become fully established.

  • Stage: Proven, Our own work

    A farm in Takehara, Hiroshima Prefecture, used it against the problems that come from growing maize in the same field year after year, and has gone on using it for other crops since.

Related uses

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A bag of treated rice husks on an exhibition table

Bringing abandoned farmland back into use

An idea for using treated rice husks to bring fields that are no longer farmed back into cultivation.

  • Stage: Concept,

    We are considering using treated rice husks to speed up soil building, so that abandoned farmland can be cultivated again and more people can take up farming.

Related uses

Talk to us about “Bringing abandoned farmland back into use”
A river running through a valley, with fields beyond

Restoring salt-damaged farmland (Noto and elsewhere)

An idea for using treated rice husks to restore the soil of fields damaged by salt.

  • Stage: Concept,

    We are considering using treated rice husks to restore the soil of farmland damaged by salt, in Noto and elsewhere.

Related uses

Talk to us about “Restoring salt-damaged farmland (Noto and elsewhere)”
Grassy land and houses near the sea
Noto (July 2026)

Ways to work with us

How to read the stages

Stage: Proven,
Results checked at sea or in the field, and on record
Stage: Being tested,
Trials, prototypes or development under way
Stage: Concept,
At the planning stage, including ideas shown as exhibits or prototypes

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