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.
Porphyra
Most human cultures with access to "Porphyra" use it as a food or somehow in the diet, making it perhaps the most domesticated of the marine algae, known as laver, "nori" (Japanese), "amanori" (Japanese), "zakai", "gim" (Korean), "zicai" (Chinese), karengo, "sloke" or "slukos". The marine red alga "Porphyra" has been cultivated extensively in many Asian countries as an edible seaweed used to wrap the rice and fish that compose the Japanese food sushi and the Korean food "gimbap". In Japan, the annual production of "Porphyra" species is valued at 100 billion yen (US$1 billion).