At Tohsei Kokan, we sell iron powder for iron-coated seeds, iron-coated seeds and subcontract direct rice sowing work by unmanned helicopter. Iron-coated seeds are rice seeds that have been coated in iron powder in order to increase their weight. Rice cultivation in Japan – raising and transplanting rice seedlings – has traditionally been costly, time-consuming and labor-intensive. We have been developing iron-coated seed technology since 2004. The seeds can be sown directly in the field without having to raise seedlings first. This offers numerous advantages, and so has been gaining attention in recent years. We are happy to support customers’ needs, from partial assistance, such as providing iron powder or iron-coated seeds, to total support including direct sowing of seeds by an unmanned helicopter. We can help you to reduce costs and labor. Please feel free to contact us.


  • Reduces production costs:
    We estimate the rice production cost to be approximately half that of traditional cultivation.
  • Labour-saving:
    Work such as raising and transplanting seedlings is greatly reduced.
  • Prevent damage by birds:
    Seeds form a tough coating, preventing damage by birds.
  • Long-term storage of seeds:
    Seeds can be stored long-term, so you can still work during the agricultural off-season.
  • Specific weight to avoid floating seedlings:
    Iron-coated seeds are heavier, so floating seedlings can be avoided.

Iron-coated seeds cultivation by direct sowing

2011 actual:
3,000ha =0.2% of National rice field area〈150Mha〉   
Iron powder usage : 80 tons

Forecast: next 10 years: 
450,000ha=30% of National rice field area〈150Mha〉
Iron powder usage : 11,000 tons

*Source: ZEN-NOH

Quantity of materials (weight)

The basic mixing ratio of rice seed to iron powder is 1 to 0.5, e.g. 10kg seed requires 5kg of iron powder. About 10-20% of calcined plaster should be mixed with the iron powder. The ratios can be changed depending on the soil and environment.

Example of mixture/weight ratios for iron coating

(Seed 5kg and area of 1km2).

※Reducing the proportion of iron powder increases the possibility of damage by birds.

We can assist with the sowing of the seeds using a radio-controlled helicopter. Our trained operator can disseminate the iron-coated seeds by radio-controlled helicopter. All that is required from you is to prepare the paddy field and manage the cultivation. Please feel free to contact us.