The origins of multi-cropping agriculture in Southwestern China: Archaeobotanical insights from third to first millennium B.C. Yunnan.

Yunnan's location at the crossroad of temperate China, Northeast India and tropical mainland Southeast Asia makes it a pivotal area for the understanding of early cultural contacts and agricultural spread between these ecologically diverse regions. This paper evaluates current evidence relating to the emergence of the first agricultural systems in Yunnan. It also reviews previous theories on agricultural dispersal to Yunnan, including whether Austroasiatic speakers were responsible for the spread of rice from Yunnan to mainland Southeast Asia, and builds a new framework that allows to tie agricultural development in the region into broader patterns of early migration and exchange networks. Archaeobotanical remains attest to an initial spread of rice and millet from Central China into Yunnan in the third millennium B.C. and the establishment of a mixed-crop economy; the introduction of wheat and barley in the second millennium B.C. allowed for increased diversification of the agricultural system, with a two-season intensification trend in the late first millennium B.C. Differences in early rice cultivation ecologies between Yunnan and mainland Southeast Asia suggest that Yunnan rice farmers may not have had a primary role in the southern dispersal of rice, however, more data is needed to fully clarify the source and development of dryland cultivation of rice in mainland Southeast Asia. Supplementary Information: The online version contains supplementary material available at 10.1007/s41826-022-00052-2.