Champa rice

Timeline

1. c. 1012–1100Fujian Circuit · Fujian ProvinceNorthern Song Zhenzong sent envoys to obtain 30,000 hu of early-maturing rice seed from Champa and ordered the Jianghuai and Liangzhe circuits to promote its cultivation. Champa rice has a growth cycle of only a little over a hundred days, tolerates drought and poor soil, can avoid autumn drought, and rotates with late rice, rapidly changing Jiangnan's rice-cropping structure.
2. 1127–1230Liangzhe, Jianghuai · JiangnanAfter the court's southern flight, Jiangnan's population surged; Champa rice became one of the main varieties in Suzhou, Hangzhou, Huzhou, Xiuzhou, and other places, paired with late rice to form a double-cropping system, raising per-mu grain yield by about 30 percent over the Northern Song and laying the agricultural foundation for Southern Song prosperity.
3. 1231–1240Jiangnan rice-growing areas · Zhejiang ProvinceDuring the Song-Mongol war, grain-producing areas north of the Huai fell; the Southern Song relied more on Jiangnan's high-yielding Champa rice to maintain military rations and capital supplies. Its early-maturing traits let farmers rush-plant late rice or beans after the summer harvest, raising land utilization and supporting wartime finances and the million-strong population of Lin'an.