East Asian rice cultivars

Timeline

1. c. -3000–400Middle and lower Yangtze · JiangnanArchaeology and texts show long-term japonica cultivation in the middle and lower Yangtze, with techniques for seedling raising in ponds, paddy management, and harvesting and storage. After the Han, Jiangnan gradually became a major national granary; local varieties adapted to the humid climate and paddies at different altitudes.
2. 501–589Three Wu region of the Southern Dynasties · JiangnanIn the sixth century under the Liang and Chen of the Southern Dynasties, rice cultivation in the Three Wu region was highly developed, with japonica yields and irrigation and drainage technology leading the way. Land taxes were paid in rice and glutinous rice, so variety quality directly affected state finances. Northern regimes also promoted dryland rice and irrigation in the Huai basin.
3. 400–600Korean peninsula and Japan's Kinai region · East AsiaIn the sixth century Baekje, Silla, and Japan's Asuka period continued to introduce mainland Chinese japonica varieties and farming methods. During Japan's formative ritsuryo period, rice was established as the basis of tax grain; the Korean states likewise used rice to support military and ritual consumption, forming an East Asian rice variety exchange sphere.