Mechanized crop rotation cultivation with profitable field crops, newly introduced crops and common field crops and the establishment of high quality stable production technology. Stable production technology for the cropping system with specific application soybean. Soybean high-quality production and cost reduction technology. (Iwate Prefect. Agricultural Res. Center S, Yamagata Prefect. Agricultural Exp. Stn. S, Fukushima Prefect. Agricultural Exp. Stn. S, Nagano Agricultural Res. Center S, Animal Husbandry Exp. Stn. of Nagano Prefect. S, and Nagano Chushin Agricultural Exp. Stn. S).