There are now difficulties in reforming the agricultural structure in Japan. The accumulation of farmland to largesize farmers is not necessarily successful. On the other hand, village-based group farming that consists of part-time farmers is sometimes more successful in terms of cost reduction. At other times, the cooperation between part-time farmers and large size farmers brings about rational land use and drastic cost reduction. But the main purpose of village-based group farming is not in cost reduction but in the maintenance of regional resources, environment, rural society and lives. Their activities makes for the accumulation of social capital. When the regional trust and network based on the social capital are workable, the agricultural structure reform will be successful because the market of the farmland is not complete and the regional resources use have externalities in rural society.
