地力概念から見た中国水稲作の実態 : 宋元明清時代を中心に

摘要

Among the research on the history of Chinese agriculture in Japan, the previous research on paddy field cultivation utilized "hard-work" and "heavy-fertilizing" as analytical indicators. There is a problem with such cultivation that the amount of energy invested is large, while that of energy generated from the production is small. In order to comprehensively examine the overall picture of paddy field cultivation, it is effective to analyze it from a "soil fertility" perspective. This is a good example of effective research, because an improvement of soil fertility is not synonymous with an increase in fertilizer application. Although oil cakes were common as fertilizer by the middle of the Qing Period, and it was an age when "heavy-fertilizing" was just beginning. The application of fertilizer dependent on oil cakes can cause physiological disorders of various kinds. To solve this problem, the application of combustion ash had been considered to be effective. However, compared to the supply of oil cakes, that of combustion ash was not sufficient. Therefore, determining whether the increase in application of oil cakes led to an improvement of soil fertility remains a matter to reconsider. In Pre-modern China, there were some other methods that were considered effective to improve soil fertility, such as winter flooded paddy fields, soil dressing and paddy-upland rotation fields, etc.. However, when viewed from the modern agricultural perspective, some of them are regarded as illogical. Research on Chinese agricultural history including the ideological background of the people of the time is needed in the future.