Largest Study of GM Crops Yield Surprising Results
The largest study of genetically modified crops (GM crops) and pesticide/herbicide usage shows the reality of their impact on chemical use in farming.
The words "genetically modified" typically bring controversy with them. However, with the promise of increased yields and protection from pests and diseases, GM crops have become a feature in modern agriculture.
[Image source: UVA Today]
Using the annual data from over 10,000 farmers - half maize, half soybean - researchers from a collaboration of universities gathered information to draw conclusions. Team leader Federico Ciliberto told UVA Today:
“The fact that we have 14 years of farm-level data from farmers all over the U.S. makes this study very special. We have repeated observations of the same farmers and can see when they adopted genetically modified seeds and how that changed their use of chemicals.”
Comprising over 80 percent of US soybean and maize crops since 2008, genetically modified (GM) maize seeds are altered to make them both insect- and herbicide-resistant. GM soybeans are only altered to make them herbicide resistant. The study's findings were surprising.
While pesticide use by farmers who planted the GM maize seeds dropped by 11.2 percent, herbicide use only dropped 1.3 percent. With soybeans, modified to survive herbicides, farmers reported increasing their herbicide use by a whopping 28 percent. Ciliberto explained why this might be:
"In the beginning, there was a reduction in herbicide use, but over time the use of chemicals increased because farmers were having to add new chemicals as weeds developed a resistance to glyphosate. Evidence suggests that weeds are becoming more resistant and farmers are having to use additional chemicals, and more of them. I did not expect to see such a strong pattern.”
Future of Farming
Increased use of herbicides has massive implications for the environment, as chemicals pollute the air and waterways. Concerned about the long-term impact of this chemical bombardment, the research team explored the impact on farm workers, consumers, and the environment using a tool called the environmental impact quotient (EIQ). While they found few immediate negative effects upon the studied groups, the team still wants to learn about the impact on local ecosystems of higher doses of herbicides.
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