The interplay of millets and rice in Neolithic central China: Integrating phytoliths into the archaeobotany of Baligang

Baligang is a Neolithic site with a long occupation, from before 6300 BC up to the first millennium BC, although the bulk of excavated finds and archaeobotanical evidence from the site comes from the Yangshao, Qujialing, Shijiahe and Longshan (4300–1800 BC). The cultural group affiliation of the site varies between northern (Yangshao and Longshan) and southern (Qujialing and Shijiahe) cultural connections. The earliest occupation of the site represents a pre-Yangshao society with early cultivation of rice (Oryza). In later periods Baligang has evidence for mixed farming of both rice and millets (Setaria italica and Panicum miliaceum), although rice is the most prominent crop in the phytolith record throughout the occupation. Wetland rice cultivation is indicated throughout the Yangshao, Qujialing, Shijiahe and Late Longshan periods. However, there is a shift towards better watered rice in the Qujialing and Shijiahe phytolith assemblages, indicated by a decline in sedges (Cyperaceae) alongside occurrence of sponge spicules and diatoms. These data suggest deeper flooding of rice fields in order to suppress weeds and increase productivity, indicating that the ecology of rice cultivation changed over time. In the Late Longshan period, when millet became more prominent and the cultural influence shifted northwards, it appears that more sedge-infested and weedy rice fields became the norm, suggesting a decline in rice cultivation intensity, perhaps connected to influences of cultivation practices from the north. In addition, we can infer aspects of the organisation of crop-processing from the phytolith evidence. In the Yangshao period the remains consist of mostly dehusking waste from the final processing, suggesting storage of a more processed crop and therefore larger scale, more communal post-harvest processing. By contrast this declined in the subsequent period with more evidence for primary winnowing waste indicating a shift towards smaller social scales of harvesting and processing, such as smaller household groups replacing a more communal approach. The household-level of processing is most evident in the Late Longshan period.