Mixed farming of rice and millets became the primary subsistence strategy 6400 years ago in the western Huanghuai Plain of Central China: New macrofossil evidence from Shigu

The Huanghuai Plain is located in a transitional climate zone between the Yangtze River and Yellow River valleys in Central China, where mixed farming of millets and rice appeared 8,000 years ago. However, when this specific agricultural model became the primary subsistence strategy and how the crop structure developed in this area have not been confirmed, largely due to the lack of sufficient archaeobotanical evidence and accurate chronological data. In this study, accelerator mass spectrometer (AMS) radiocarbon dating and identification of the plant remains have been conducted at the Neolithic site of Shigu. The results indicate that mixed farming of millets and rice was practised at Shigu during the Yangshao Culture period ( ca. 6400–5300 a BP), during which broomcorn millet ( Panicum miliaceum ) and foxtail millet ( Setaria italica ) dominated. This finding is different from the earlier Peiligang Culture sites (9,000–7,000 BP) in the same research region, where wild editable plants were more abundant. Although the crop structure at Shigu changed around 6,000 years ago, with a noticeable decrease in rice cultivation, millets and rice were always the primary plant foods for the local population. The present study thus proposes the formation of a crop-based agricultural society at least 6400 years ago at Shigu in the western Huanghuai Plain of Central China.