Phytolith Evidence for Rice Cultivation from Xishanping Site in Gansu 5000 Years Ago
甘肃西山坪遗址5 000 年水稻遗存的植物硅酸体记录

The phytolith evidence of rice together with AMS 14C dating of charcoal and charred seed from Xishanping site in Gansu shows that the rice has been cultivated about 5 000 years ago in Tianshui, Gansu province. The finding of cultivated rice with accurate dating is known the oldest record, which is also the most northwest border of cultivated rice, in northwest China. The finding extends the record of cultivated rice about 2°of longitude to the west and allows us to estimate the cultivated region of rice 5 000 years ago in Easern Asia. It will help on understanding the affection of rice cultivation and spreading on agriculture and environment.