While older grains of rice have been discovered in China-in Shangshan Culture dating back 10,000 years, also located in today's Zhejiang province, carbonized rice was found-this is the first discovery of a complete, ancient rice-growing system, including paddies and irrigation channels.

"Our previous studies mainly focused on the grains, like the evolution of their varieties, to reflect how people cultivated them," Chen Xingcan, director of the Institute of Archaeology, Chinese Academy of Social Sciences, says. "But the Shi'ao site offers a rare chance to directly study human farming activities."

The discovery of the Shi'ao site may also greatly contribute to studies of a bigger picture surrounding Liangzhu Culture.

The Archaeological Ruins of Liangzhu City in Hangzhou, Zhejiang, were listed as a UNESCO World Heritage Site in 2019. It indicates a jade-worshipping civilization and the capital city of a regional state, covering a significant area around Taihu Lake.

A developed water conservation system was found around the city ruins. An estimated 200,000 kilograms of carbonated rice was unearthed in a core area of the city, but no ancient rice paddies have been found within the city ruins.

At the Maoshan site, near the Liangzhu ruins, a group of small-scale rice paddies was discovered, once thought to be a "state-owned farm", and these new findings at the Shi'ao site offer more clues to the social structure of that regional state from an agricultural perspective.

"The discovery of rice in Liangzhu city means there must have been a national-level system for rice production," Li Xinwei, a researcher with the Institute of Archaeology, says. "The Shi'ao site was thought to be on a marginal area of Liangzhu Culture, but the new findings may give us a new perspective."

Song Xinchao, deputy director of the National Cultural Heritage Administration, expects upcoming research at the Shi'ao site to unveil specific rice-growing technology of the time.

"We can also see how farmlands were managed," Song says.

"However, it's only a start, and it's too early to draw firm conclusions."