Baodun Culture in the Context of the Emergence of Rice Cultivation in the Sichuan Basin

Girchenko Ekaterina Aleksandrovna ORCID: 0000-0001-5304-2595 PhD in History Researcher; Department of Stone Age Archaeology; Institute of Archaeology and Ethnography SB RAS 17 Akademika Lavrentieva Ave., office 503, Novosibirsk Region, 630090, Russia wusong@yandex.ru

The origin of the Baodun culture remains a controversial issue in Chinese archaeology and Neolithic sites older than Baodunc have not yet been discovered on the Chengdu Plain. Yu Weichao suggests that the Baodun speakers were migrants from the territories of modern Hubei who came to the Chengdu Plain through eastern Sichuan ^[18]. Other researchers also suggest that the very principle of building walls of fortified settlements indicates interaction with the region of the middle reaches of the Yangtze River, where similar settlements associated with the cultivation of rice culture were found. There is a version that the Baodun culture appeared around 4700-4500 BC on the basis of migrations from the northwestern regions of modern Gansu and Qinghai ^{[1, p. 47]}. Perhaps the earliest Neolithic groups in the Chengdu plain were migrants from the territory of southern Gansu, who went south around 3000 BC and advanced through the Bailong Valley and the valley of the Minjiang River, first to the northwest of Sichuan, and then south. Only the absence in Baoduncun of painted ceramics typical of the south of Gansu of the ivth and III millennia BC causes some doubts about the correctness of the construction of migration schemes. Thus, archaeological data that could confirm direct links between Gansu, northwestern Sichuan and the Chengdu Plain is still insufficient. This is partly due to the small number of archaeological works in the western part of Sichuan, the lack of descriptions of the stratigraphic context of the finds and a sufficient number of radiocarbon dates.

Despite the fact that the theory described above about the origin of Baodun is generally working, the formation of culture cannot be attributed solely to the cultural influences of the mountainous northwest, since the archaeobotanical conclusions for both millet and rice suggest a connection with other regions. Ashtray samples indicate a transition from the cultivation of common millet (Panicum miliaceum) and Italian millet (Setaria italica) circa 3000-2600 BC to the combined production of rice (Oryza sativa japonica) and Italian millet by the end of this phase circa 2600 BC. Three potential routes for the spread of rice farming in the Chengdu plain have been proposed: 1) through the upper valley of the Hanjiang River north of the Sichuan Basin, through the territories of the modern cities of Danjiangkou, Shiyan, Yunxian and Yunxi counties, 2) through Three gorges of the Yangtze River in the eastern part of Sichuan and 3) through the foothills of northern Guizhou. The immediate homeland of rice cultivation was the area of the middle and lower reaches of the Yangtze River. The settlement of people who grow rice and millet is often seen as a key moment in the history of the population of East and Southeast Asia associated with the establishment of settlement. Nevertheless, all working hypotheses about human settlement in the Neolithic, based on rice cultivation, need further confirmation.

There are also discussions in the research literature on the causes of the appearance of fortified settlements in the Neolithic of Sichuan. Despite the fact that some Chinese archaeologists believe that the walls were primarily intended to protect against floods ^[8], basing their assumptions on the shape of the gentle external slopes and the functions of ditches as drainage channels, there are other theories related to the development of ancient societies. Other scientists suggest that population growth as a result of the development of agriculture could sometimes be very rapid ^{[19, p. 14-19]}, especially among a population that depended more on agriculture than on hunting and gathering. The growing population occupied the surrounding uninhabited territories, gradually developing them. A sharp increase in population could have occurred on the Chengdu Plain between 2500 and 2000 BC, since the settlements of the Baodun culture significantly outnumber any sites of an earlier time. Probably, such population growth continued until all suitable lands were developed, after which the next stage was the intensification of subsistence farming methods. The appearance of fortified settlements in the Neolithic is an indirect sign of the manifestation of tension associated with population growth, as well as the appearance of a large number of stone spearheads and arrows, which in other regions of China is often referred to as a key indicator of social complexity and the first prerequisites for the emergence of city-states ^[20].