Millet isotopes reveal advanced agriculture in early imperial China
A new study reveals how ancient Chinese farmers managed soil fertility and water resources over thousands of years. By analyzing carbon and nitrogen stable isotopes in millet crops, the research provides long-term isotopic evidence of farmland management practices in the Guanzhong Basin—the political heartland of early imperial China.
The research is in the journal CATENA.
Foxtail millet and common millet were domesticated in China around 10,000 years ago. For several millennia thereafter, they were the most important crops in northern China.
"Archaeologists already have a good understanding of millet's dietary role in the Neolithic period," says researcher Jingwen Liao. "Now we want to understand how millet farming practices evolved from prehistory into early historical times in response to climate fluctuations and soil nutrient depletion."
"In densely populated capitals," she adds, "maintaining crop production was essential to keep the state running."
Grain-filled pottery models from Han tombs
In the Han Dynasty (202 BC–AD 220), pottery model granaries filled with real grains were commonly buried in tombs. These provide ideal materials for agricultural research. "Since they were sealed in a known context, we don't need to worry about dating," Jingwen notes.
This study obtained 104 carbon and nitrogen isotope values from millet crops—the largest such dataset for ancient crops from the Late Neolithic to the Han Dynasty in China's core regions.
"It allows us to trace long-term changes in land use," says Jingwen.
More information: Jingwen Liao et al, Millet stable isotopes reveal the advance of agricultural practices in the core political regions of early imperial China, CATENA (2025).
Provided by Leiden University