US farmers have benefited from the introduction of genetically modified crops, according to a new report * published today by the National research Council of the National Academies. Farmers who switched from conventional crops have seen higher profits and a reduced environmental impact, the committee concluded. However, many benefits such as improving water quality, need to be better quantified, and some biotech crops are threatened by the development of weeds resistant to herbicides.
Over 80% of corn, soybean, and cotton acreage in the US is planted with modified crops to resist pests and improve weed control. During the last decade, groups of experts convened by the National Research Council examined the potential risks to human health and the environment, such as gene flow between agencies. But they had not taken a broad look at what the impact was on farms that grow biotech crops. For example, NRC commissioned a group of 10 experts combing the scientific literature.
"The evidence is quite strong is that these technologies have both economic and environmental benefits," says David Ervin of Portland State University economist in Oregon, who chaired the panel. But many effects need to be better studied. The committee recommended, for example, the US Geological Survey to study the impact of reduced tillage has had on water quality.
Charles Benbrook, chief scientist of the OrganicCenter in Enterprise, Oregon, is unsure of the persistence of the economic benefits. Benbrook, who was not on the NRC panel, said that strong price increases biotech seeds, which began in 07, could erode economic gains for farmers.
The group also highlighted several risks. One of the most important is that the resistance of insects or weeds will make genetically modified crops inefficient farmers and strength to return to more toxic chemicals or plowing causing soil erosion. Economist Dermot Hayes Ames says State University of Iowa, he is optimistic that new types of crops and biotechnology management will solve the problem of resistance, but Benbrook is less optimistic. "It's a crisis now," he said.
A news story about the report published in this week's issue of Science .
* The impact of GM crops on agricultural sustainability in the US . Washington The National Academies Press, 2010.
0 Komentar