Modern farmers in the Amazon region could take lessons in sustainability from the area's inhabitants of 800 years ago, scientists say.

Research led by the University of Exeter in Britain showed indigenous people living in the savannas around the Amazonian forest farmed without using fire to clear forest by practicing 'raised-field' farming, which involved constructing small agricultural mounds.

These raised fields provided better drainage, soil aeration and moisture retention in an environment that has both drought and flooding, an Exeter release said Monday.

While it has long been assumed indigenous people used fire as a way of clearing the savannas and managing their land, the study proves raised-field farming limited fires, which helped conserve soil nutrients and organic matter, and preserve soil structure, researchers said.

"This ancient, time-tested, fire-free land use could pave the way for the modern implementation of raised-field agriculture in rural areas of Amazonia," Exeter researcher Jose Iriarte said.

"Intensive raised-field agriculture can become an alternative to burning down tropical forest for slash and burn agriculture by reclaiming otherwise abandoned and new savannah ecosystems created by deforestation."