Genetically modified (GM) crops may contribute to increased productivity in sustainable agriculture, according to a groundbreaking study published in the June 8 issue of the journal Science. The study analyzes, for the first time, environmental impact data from field experiments all over the world, involving corn and cotton plants with a Bt gene inserted for its insecticidal properties.
The research was conducted by scientists at the National Center for Ecological Analysis and Synthesis (NCEAS) at the University of California, Santa Barbara, The Nature Conservancy, and Santa Clara University. The study is accompanied by a searchable global database for agricultural and environmental scientists studying the effects of genetically engineered crops.
Biotechnology and genetic engineering are controversial because of concerns about risks to human health and biodiversity, but few analyses exist that reveal the actual effects genetically modified plants have on other non-modified species. In an analysis of 42 field experiments, scientists found that this particular modification, which causes the plant to produce an insecticide internally, can have an environmental benefit because large-scale insecticide spraying can be avoided. Organisms such as ladybird beetles, earthworms, and bees in locales with "Bt crops" fared better in field trials than those within locales treated with chemical insecticides.
"This is a groundbreaking study and the first of its kind to evaluate the current science surrounding genetically modified crops. The results are significant for how we think about technology and the future of sustainable agriculture," said Peter Kareiva, chief scientist of The Nature Conservancy.
According to lead author, Michele Marvier, of Santa Clara University, "We can now answer the question: Do Bt crops have effects on beneficial insects and worms" The answer is that it depends to a large degree upon the type of comparison one makes. When Bt crops are compared to crops sprayed with insecticides, the Bt crops come out looking quite good. But when Bt crops are compared to crops without insecticides, there are reductions of certain animal groups that warrant further investigation." What is clear is that the advantages or disadvantages of GM crops depend on the specific goals and vision for agroecosystems.
As NCEAS Director, Jim Reichman explains, "This important study by an interdisciplinary research team reveals how an in-depth analysis of large quantities of existing data from many individual experiments can provide a greater understanding of a complex issue. The project is enhanced by the creation of a public database, Nontarget Effects of Bt Crops, developed by NCEAS ecoinformatics expert, Jim Regetz, that will allow other scientists to conduct congruent analyses."
Materials provided by National Center for Ecological Analysis and Synthesis/UCSB. Note: Content may be edited for style and length.
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