Chinese archeologists say relics of ancient rice they have unearthed from a heritage site about 3,500 years from today may shed light on how rice farming started on the country's southwestern plateau.

The plateau that covers the southwestern provinces of Yunnan and Guizhou was for a while believed by many scientists to be the cradle of paddy farming, but little evidence was available to support their hypothesis until recent excavations of nearly 50 kilograms of carbonized rice from three ancient sacrificial pits in Zhongshui, a town in Weining Yi, Hui and Miao Autonomous county, with an average altitude of 1,800 to 2,000 meters.

Besides the rice relic, archeologists also unearthed from the site a large quantity of stone implements, chinaware, jade and bronze pieces, said Zheng Herong, a research fellow with the Guizhou Provincial Institute of Archeology.

"We're convinced now that at least 3,500 years ago, rice farming was already popular on the plateau," said Dr. Zhao Zhijun, an archeologist with the Chinese Academy of Social Sciences. "The people had more than enough to feed themselves, they used rice as sacrificial object for the dead."

Zhao, one of the leading scientists engaged in plant archeology in China, proposed the first cultivated rice could be dated back more than 10,000 years.

According to Zhao, the discovery of ancient rice relic, along with ideal climate and soil conditions and archeological findings evidencing an advanced stage of agricultural production, is an important proof of rice farming, a subject that has been popular yet controversial among archeologists, agriculturists and historians over the past three decades.

Yet Dr. Zhao said scientists still need to determine whether the relic was paddy rice or dry rice and whether it was native to the plateau or had been introduced from other known rice production bases in the middle and lower reaches of the Yangtze River -- China's longest waterway -- or the Sichuan Basin north of the plateau. "These are crucial in our research on highland rice farming."

South China, with plentiful rainfall and a mild climate, is widely believed to be origin of rice farming. Many scientists believe that highlanders in the southwestern plateau were the first to cultivate rice and excavation of Neolithic stone implements, including farm tools, seemed to support their hypothesis, said Zhang Herong, an archeologist based in Guiyang.

A theory was first set forth by an American scholar in 1952 that the world's agriculture first burgeoned in southeast Asia, south China included, but the theory did not arouse enough attention back then, according to Dr. Zhao.

(Xinhua News Agency May 30, 2005)