Abstract
1) In order to investigate the growing process of soybean with high yields, this experiments were carried out on a grower's fields of rich soils at Imoda, Tamayama village, Iwate prefecture (alluvial soils derived from the Kitakami river), compared with experimental fields of Tohoku Nat. Agr. Exp. Station at Kuriyagawa Morioka city (volcanic ash soils derived from Mt. Iwate) in 1960 and 1962 testing with 2 of 3 varieties. 2) Top growth in early stage was more stimulated at Imoda than at Kuriyagawa, but after the flowering period, the growth rate became lower at Imoda. The number of grains per area and ratio of grain weight/stem weight at Imoda were greater than that of Kuriyagawa excepting Toiku No. 73 (early variety). 3) Characteristics of growing process on each field as mentioned above were also recognized by the pot experiment in which pot were exchanged between testing places each other at several important stages of growth for soybean plant. 4) It can be said that climatic conditions and soil moisture scarecely play an important part on the growth type in this experiment. 5) P, N and Ca % per dry matter in the soybean plant at Imoda field were higher than at Kuriyagawa as earlier stage of growth. Especially P % were remarkable in this case. But as the stage be later, it became a little lower in the plant of Imoda than that of Kuriyagawa. 6) The favourable growing of soybean plant for high productivity were made clear from morphorogical and physiological conditions by these works.
