The agricultural basis for the continuous development of the Central Plains civilization: A systematic radiocarbon dating and archaeobotanical study at the Qingtai site, central China

The area surrounding Songshan Mountain is the core area where the Central Plains civilization originated and developed. However, the agricultural basis of the Central Plains civilization is still not very clear, especially lacking a high-precision chronological framework. In this paper, archaeobotanical analysis and AMS 14 C dating test were conducted at the Qingtai site, with 935 soil samples and 20 dating materials collected. And 106,106 charred plant remains were recovered. Abundant charred seeds and high-precision chronological data indicated that from the mid-late Yangshao to the early Longshan period (ca. 5500–4700 BP), the Qingtai site developed mixed farming that foxtail millet ( Setaria italica) dominated, while common millet ( Panicum miliaceum) and rice ( Oryza sativa) occupied a relatively lower position. Combining with archaeobotanical data from other sites spanning from the late Yangshao to the Longshan period (ca. 5300–4000 BP) in the Central Plains, this study demonstrated that the mixed farming which has existed in the Songshan region since the middle Peiligang period provided the basis for social complexity and the continuous development of the Central Plains civilization. During the late Longshan period, the ancestors increased efforts to cultivate soybean ( Glycine max) and introduced wheat ( Triticum aestivum). Research also showed that crop structure was more closely related to geographical location and site areas. During the late Yangshao period, the large-scale settlements in northern Songshan promoted dry farming, in which foxtail millet was the staple food. However, the crop system in southern middle-size and small sites had local features, in which rice or common millet played a relative important role in farming. During the late Longshan period, five crops were more likely to be cultivated at the large-scale settlements. This study provides the latest archaeobotanical evidence, contributing to a further exploration of the relationship between agriculture development and the civilization process in Central Plains.