2. System of harvesting of rice and soybean in Japan 1) Rice In 1966. reaping by sickle was practiced in over 99 % of rice planted field in Japan Since then reaper-binder and head-feeding combine were gradually developed and in 1990, 1.3 million units of binders and 1. 2 million units of head-feeding combine were pervaded. The area of the rice field harvested by those harvested by those harvesting machines has reached to 99% of the total rice field.