SCIENCE-TECHNOLOGY, ECONOMICS, AND EVERYDAY LIFE
250–600: Agricultural techniques and tools evolve, with large-scale canal building and the subdivision of rice paddies, as well as the adoption of a step plow, the use of iron blades for hoes and reaping knives, and the use of horse-drawn cultivating equipment. Large manufacturing sites arise for salt production, stone beads, and ceramics, including the characteristic gray sue ware.
250–400: Early Kofun period. The rice basket of Japan centers on the Nara region, which grows most of the rice for the palace. Barley, millet, and wheat also are grown, probably using slash-and-burn methods. Special regional foods, such as trout and mushrooms, are presented as tribute to rulers.
400–500: Middle Kofun period. A specialized warrior elite emerges, as shown by iron armor, weapons, and horse gear. Numbers of craftsmen immigrate from the Korean state of Paekche. They make such luxury goods as gold jewelry, ornaments, ceramics, brocade and patterned cloth, and gilt bronze horse trappings. Large-scale canals are built to improve the irrigation of fields. Stone coffins and hollow clay figurines known as haniwa are made for Kofun tombs.
604: The Chinese calendar is adopted and remains in effect to c. 690.
646: The Taika Reform results in large-scale land surveys, the institution of a grid (jori) system of one-hectare square field sections, and reallocation of fields to peasants.
c. 660: The Mizuochi water clock, based on a Chinese device, is erected as a two-story building in Nara Prefecture. The bell and drum are sounded to mark every thirty minutes.
683: Government orders the use of coins to facilitate financial exchanges and to stimulate the economy. The burgeoning bureaucracy requires the documentation of all transactions in the form of inscriptions on