History Forum / General / Archaeology / September 2007

Little by little the origins of agriculture, urban existence and
those other attributes of aculture and civilization are being
"discovered" or realized by scholars.

"The dates are in a beautiful sequence, and really tight,"
anthropologist Gary Crawford of the University of Toronto at
Mississauga, who was not involved in the research.

http://www.latimes.com/news/nationworld/world/la-sci-rice27sep27,0,3062127.story
?coll=la-home-world

Rice grown in China 7,700 years ago
People burned trees in coastal marshes, converting them to paddies,
and built dikes to keep the sea from crops, researchers find.
By Thomas H. Maugh II
Los Angeles Times Staff Writer

September 27, 2007

Stone Age people began cultivating rice in what is now China more than
7,700 years ago by burning trees in coastal marshes and building dams
to hold back seawater, converting the marshes to rice paddies that
would support growth of the high-yield cereal grain, researchers
reported today.

New analysis of sediments from the site of Kuahuqiao at the mouth of
the Yangtze River near present-day Hangzhou provides the earliest
evidence in China of such large-scale environmental manipulation,
experts said.

"It shows people were changing the environment, actively manipulating
the system, and well on their way to having an agricultural way of
life," said anthropologist Gary Crawford of the University of Toronto
at Mississauga, who was not involved in the research.

Using data from the site, it is possible to extrapolate a timeline
back to the first attempts at domesticating rice, which would have
occurred about 10,000 years ago, said archeologist Li Liu of La Trobe
University in Victoria, Australia, who was also not involved. That is
contemporary with the development of agriculture in the Middle East.

The finding also sheds new light on an ongoing controversy in
archeology: How long did it take for crops to become fully
domesticated?

The evidence from China, and new finds elsewhere, indicates that the
process took much longer than previously thought, said archeobotanist
Dolores Piperno of the Smithsonian Tropical Research Institute in
Panama.

Nonetheless, she said, there is now "little doubt that by 7,700 years
ago, these people were dedicated rice farmers. . . . I think people
were getting all the benefits of agriculture before plants were fully
domesticated."

When agriculture developed is a key question in archeology because the
production of abundant food, thereby freeing time for other pursuits,
is one of the chief requirements for development of a civilization.

Kuahuqiao was discovered in the early 1970s after it was exposed by
the construction of a brick factory. The site is buried under 9 to 12
feet of sediment, which led to remarkable preservation of organic
materials.

Chinese archeologists have found remnants of wooden houses built on
stilts over the water, fine pottery that initially made researchers
think the site was more recent, bamboo and wooden tools and even a
dugout canoe, complete with paddles.

In the newest study, Yongqiang Zong of Durham University in England
and colleagues from East China Normal and Fudan universities in
Shanghai studied the sediment itself, looking for pollen, algal and
fungal spores and charcoal from fires. Their report in the journal
Nature provides a precise timeline for occupation of the site.

The site was originally a marshy freshwater environment dominated by
birch and willow trees and then alders. "Then, about 7,700 years ago,
a group of humans moved in," Zong said in a telephone interview.
"There was a sudden increase in the use of fire and the disappearance
of the older type of vegetation."

The trees were replaced by rice and cattail, which was also used as a
food source. "The human activity there was quite intense," Zong said.
Particles of charcoal in the sediment indicate that inhabitants burned
brush regularly to keep the site clear, and pig bones and other
evidence indicate that they were using manure to fertilize the
paddies, he said.

Researchers know that ocean levels were gradually rising during this
period from the melting of ice after the end of a glacial period. If
there had been no humans at Kuahuqiao, the water in the marsh would
have become more brackish over the years, Zong said.

The pollen and fungal evidence, however, doesn't indicate increasing
saltiness. That suggests that the people who lived there erected low
earthen dikes, called bunds, to keep the seawater out so that it did
not impair rice growth, he said.

By about 7,550 years ago, however, the ocean had risen so much that
the primitive dikes could no longer hold it back. The site was
inundated, and its residents were forced to move to safer areas up the
coast and perhaps inland as well.

"They continued cultivating rice, leading to the completion of
domestication more than 1,000 years later," Zong said.

"The dates are in a beautiful sequence, and really tight," said
Toronto's Crawford.