Around 10,000 years ago, as people in present-day West Asia began to domesticate wheat and barley, a similar development took place in China where people began to cultivate rice. This marked the emergence of rice agriculture, which has had a profound influence on people's lives in various parts of the world ever since.

For years, Shangshan Culture, a Neolithic culture from 11,000 to 8,500 years ago in the Jinqu Basin in the middle and western part of East China's Zhejiang province, has been widely recognized as a source of rice agriculture with many related relics found in its sites. A new discovery may add insights into the Shangshan people's rice domestication, announced by the National Cultural Heritage Administration in Beijing on Sept 13.

The Huangchaodun Site, dating back 9,300 to 8,000 years in Quzhou, Zhejiang, recently unveiled remnants of settlements surrounded by a moat. More importantly, an area to the east of the settlements, covering 15,000 square meters, is possibly the earliest rice field ever discovered with a dense distribution of rice phytoliths, or remains of rice, according to Zhang Sen, a researcher with the Zhejiang Provincial Institute of Cultural Relics and Archaeology.

Zhou Dongya, a member of the archaeological team, told Zhejiang Daily that only fields that have been cultivated with rice will leave behind a large amount of phytoliths. Archaeologists have found that the field has an extremely high density of rice phytoliths, which are distributed in independent blocks, suggesting this was a land where early settlers had cultivated rice.

"We found carbonized rice and rice husks at the site. And scholars have studied them with the conclusion that they belong to domesticated rice. Since rice has been domesticated, where is the rice field? Now, we may have found it," says Zhang.

Moreover, the potential rice field is not solitary, but is a complete system. According to Zhang, covering an area of 70,000 square meters, the site has the rice field and two platforms surrounded and separated by a moat. The layout is like a pear, with one smaller platform in the north, a larger one in the south and the field to the east of these platforms.

Zhang says the settlements should be on the platforms, which are yet to be excavated.

To the west of the site, scholars have found an ancient waterway and pond. There seems to be a suspected ancient ditch linking the pond with the moat, maybe an artificial drainage ditch, he adds.

They also discovered an area to the west of the site where a large amount of wild rice seemed to have grown.

"This means the local environment was favorable for the natural growing of rice and the area had conditions for people to domesticate rice. Maybe that was why people were attracted to settle in this place," says Zhang.

"From discoveries at the site, we generally believe during this period, the framework of rice agriculture society had gradually become clear and may have even surpassed the formation stage," he adds.

Archaeologists infer the site belongs to the middle and late period of Shangshan Culture and Kuahuqiao Culture, a Neolithic culture found in the northern part of Zhejiang dating from 8,000 to 7,000 years ago. They hope to find the relationship between the two ancient cultures in future studies.

Other finds include pottery vessels from both the Shangshan and Kuahuqiao periods, including jars, plates and bowls.

Huangchaodun is especially important among the 24 Shangshan sites discovered since the structure of others are mostly destroyed or under modern houses that are not easy to excavate. As a result, it's rare to unveil the complete layout of a Shangshan cultural site, says Zhang.

Lin Liugen, an archaeology professor at Zhejiang University, says scholars have excavated a series of rice fields from sites in Zhejiang and formed a systematic way to study them.

And the Huangchaodun Site remains special as it yields the earliest rice field among them.

"Based on our search for rice fields in the middle and late Neolithic period, we have developed a research method for locating them. This method includes preliminary field surveys, systematic exploration and sampling, archaeo-botanical analysis, and focused excavations of key areas. By further improving this working model, we believe we will discover more early rice fields, further advancing our exploration of early rice agricultural society," says Zhang.

Zhang Chi, an archaeology professor at Peking University, also highlights the preservation of the settlement landscape.

He points out the layout of two platforms — if they are analyzed to be of the same time, they may offer clues for a very elaborate society.

"The two platforms, or two settlements, are separated by a moat. They possibly belonged to two different groups of people living together," Zhang Chi says.

Similar phenomenon had been discovered at the Baiyinchanghan Site of the Xinglongwa Culture, a Neolithic culture dating back 8,200 to 7,200 years in today's Inner Mongolia autonomous region and Northeast China, he adds.

He says the Baiyinchanghan Site in Chifeng, Inner Mongolia, also unveiled two settlements separated by moats, very close to each other. And the Huangchaodun Site is more than 1,000 years earlier than that.

Zhang Chi urges more studies on the identification of the rice field and reasons why it can still be preserved to this day.

"We generally believe it's hard for a rice field to be preserved for several thousand years. Only under very special conditions, could the field have continued to be utilized by people of later generations. We still need further studies to confirm if it was really a rice field," he says.