The Japanese agricultural sector accounts for about 1.2% of the total country's GDP . Only 11.5% of Japan's land is suitable for cultivation. Because of this lack of arable land, a system of terraces is used to farm in small areas. This results in one of the world's highest levels of crop yields per unit area, with an agricultural self-sufficiency rate of about 50% . Japan's small agricultural sector is highly subsidized and protected. There has been a growing concern about farming as farmers are aging with a difficult time finding successors.