The drastic increase in Japan's population during its medieval period signified the ability of the country to create enough fields close to a population to be able to support a denser population. A. The reason for the consolidation of citizens lied in a number of different factors, such as the formation of religious communities or simply voluntarily. B. Field leveling was a practice that allowed the cultivation of two entirely different types of crops with very efficient use of land. C. Farmers now had access to the marshlands of Japan close to rivers that were, as yet, not controlled by humans. D. Numerous advancements in land utilization, such as dams and dikes, as well as the practice of double cropping allowed farmers to maximize the possible output from a single patch of land. E. Koreans noted that farmers in the Hyogo region of Japan had accomplished a smooth triple cropping annual cycle that used the land during the entire year. F. The aspiration for land above that required to achieve fulfillment of food needs was curbed by the existence of several factors, such as limited land resources.