Wild and domesticated forms of rice (Oryza sp.) in early agriculture at Qingpu, lower Yangtze, China: evidence from phytoliths

Rice cultivation in parts of the Yangtze valley, eastern China, is thought to date to at least the early Holocene. Using phytolith analysis, sediments from an exposed profile at Qingpu in the lower Yangtze were examined in detail in order to contribute to the growing body of information relating to the history of rice agriculture in the Yangtze delta area. The presence of phytoliths from domesticated rice, Oryza sativa, indicates that rice agriculture was well developed at Qingpu by ca. 2350 BP and may have increased in intensity from ca. 2100 BP. Rice cultivation at Qingpu was comparatively late in relation to other areas in the Yangtze valley, possibly due to the seasonal intrusion of saline waters, while the cultivation of wild rice remained a prominent feature of food production in the area to at least as late as ca. 1800 BP. Results presented here support the existence of a period of overlap, during which both wild and domesticated forms of rice were cultivated, rather than a linear transition from wild to domesticated rice cultivation and the possible influence of environmental factors over farming in an area subjected to frequent flooding.