The British embassy in Brasilia has given 1.2 million reais ($480,000) to the project, which US environmental group The Nature Conservancy hopes will help bring soybean certification to the whole of the Amazon and possibly all Brazil.

"Soy is one of the engines of deforestation," said Ana Cristina Barros, head of The Nature Conservancy in Brazil. "Our objective is to stop deforestation."

Brazil is the world's second-largest soybean producer but is expected to overtake the United States in a few years as it develops vast areas of the interior, including its central 'cerrado' savannas and the Amazon, for soy farming.

Soy represented about 10 percent of the country's exports last year, at around $10 billion.

Environmentalists see the extension of soybean farming as a main culprit behind a jump in Amazon destruction to its second-highest level in 2002-2003.

In that period an area of the Amazon -- the world's largest tropical forest and home to up to 30 percent of all animal and plant species -- larger than the US state of New Jersey was cut down. Last year's figure is expected to be similar.

"There is no doubt that soy is clearly expanding in Brazil's two biggest biomass regions; the cerrado and the Amazon," said Joao Paulo Capobianco, the government's secretary of biodiversity and forests.

Certification has already been introduced for Amazon wood.

Sergio Barroso, head of Cargill in Brazil, said his company was committed to the project, which could prove crucial since Cargill buys about 80 percent of the soy produced in Santarem.

"We already decided that we will only work with producers that respect the environment," Barroso said. He said the project could be extended to other areas of Brazil if it works in Santarem.

Farmers' requirements would include maintaining forests around fields and respecting environmental laws.

David Cleary, who heads The Nature Conservancy's Amazon program, said certification for soy could work because there are relatively few buyers.