2020 Volume 82 Issue 2 Pages 129-137
To speed up soybean seeding, we have been developing a ridge-forming seeder with disc cultivation and a double plate-type seeding mechanism. With an experimental machine, a maximum seeding speed of up to 1.5 m/s was achieved. However, when chemical-coated seeds were used, 20 % were damaged and 30 % were missed. Those chemicals were insecticide and fungicide, and the utilization of those seeds has increased in recent years. The dynamic friction resistance of the seeds was doubled by the coating; moreover, it reached was tripled when chemicals were adhered to the inside of the seeder. To solve these problems, a U-shaped pocket seeding plate was proposed. After the tests of four brands and three sizes, damaged seeds were almost eliminated. In addition, stable operation was achieved to within the 2 % of missing seeds, and the release speed was 20 /s (equivalent to a working speed of 2.5 m/s).
