New evidence that agriculture was practiced in a southern region of ancient China before domesticated rice production techniques arrived in the area completely upends the conventional ideas of how agriculture emerged in China, according to new research.
Research from the University of Leicester and the Chinese Academy of Sciences indicates that people living in the southern subtropical region of Xincun 5,000 years ago may have grown a variety of foods and, surprisingly, could have even ignored actively cultivating rice -- the domestication of which is considered the dawn of agriculture in southern China.
The theory comes from a novel analysis of ancient grindstones.
Huw Barton, from the School of Archaeology and Ancient History at the University of Leicester, said that his team's method is a relatively new technique that involved extracting very small bits of sediment trapped in the pits and cracks on the grindstones' surface. At a lab in Beijing, Barton's colleague Xiaoyan Yang conducted an analysis of starches found on the ancient sediment.
"At Xincun we really hit the jackpot," Barton said in a statement. "Starch was well-preserved and there was plenty of it."
Barton said that some of the starch granules they found, such as freshwater chestnuts, lotus root and fern root, were expected, but "finding starch from palms was totally unexpected and very exciting."
Several types of tropical palms store great quantities of starch, which can be crudely extracted and dried into edible flour. It is not particularly delicious, but it is a reliable source of nutrients that can be processed year-round.
Many communities in tropical regions rely on flour derived from palms today, according to University of Leicester.
"The presence of at least two, possibly three species of starch producing palms, bananas, and various roots, raises the intriguing possibility that these plants may have been planted nearby the settlement," Barton said.
The communities that rely on palm flour today systematically plant crops near their villages so they can easily exploit the plants. Barton thinks that if people in ancient Xincun actively planted starch-bearing plants near their settlements, it "implies that 'agriculture' did not arrive here with the arrival of domesticated rice, as archaeologists currently think, but that an indigenous system of plant cultivation may have been in place by the mid Holocene."
"The adoption of domesticated rice was slow and gradual in this region; it was not a rapid transformation as in other places. Our findings may indicate why this was the case," Barton said.
"People may have been busy with other types of cultivation, ignoring rice, which may have been in the landscape, but as a minor plant for a long time before it too became a food staple. Future work will focus on grinding stones from nearby sites to see if this pattern is repeated along the coast."
The research is published in the journal PLOS One.