Tōhoku region
Tōhoku was traditionally considered the granary of Japan because it supplied Sendai and the Tokyo-Yokohama market with rice and other farming commodities. Tōhoku provided 20 percent of the nation's rice crop. The climate, however, is harsher than in other parts of Honshū due to the stronger effect of the Siberian High, and permits only one crop a year on paddy fields.
Economic history of Japan
As late as 1955, some 40% of the labor force still worked in agriculture, but this figure had declined to 17% by 1970 and to 7.2% by 1990 and under 5% in the 21st century as Japan imported more and more of its food and small family farms disappeared.