Development of crop growing from the late Yangshao to early Longshan period in the Zhengluo region of central China: phytolith evidence from the Shuanghuaishu site

The Zhengluo region in central China is the core area for the start of the process from which Chinese civilization emerged during the late Yangshao Culture (LYS, ca. 5.5–5.0 ka bp) and the early Longshan Culture period (ELS, ca. 5.0–4.5 ka bp). During this time, agriculture must have played a major role by providing stable food resources. However, information on the farming methods during this period is rare, especially from large settlement sites. This paper discusses the study of 77 soil samples from Shuanghuaishu (ca. 5,290–4,527 bp), the largest settlement site of the LYS to ELS period ever discovered in the middle catchment of the Huang He (Yellow River). Abundant phytoliths from Panicum miliaceum (broomcorn millet) and Setaria italica (foxtail millet) were found, together with a small amount from Oryza sativa (rice), indicating that millets were more important than rice at Shuanghuaishu. Further statistical analysis reveals varying amounts of rice throughout the period of site occupation, which may be due to the local gradual climate change from warm to cold and dry, as well as the change of the nature and size of the site. Combining previous studies, it is also proposed that farming was based on a range of several crops starting in the LYS period. The development of agriculture, consistently dominated by millets in the Zhengluo area, could have provided stable food resources for the local population and thus made possible increasing social complexity and the development of civilization. This study provides the latest archaeobotanical data from the largest settlement site in the area, contributing to a further exploration of the relationship between the development of agriculture and of civilization in central China.