American researchers from the University of Virginia have conducted a 14-year study on genetically modified (GM) crops and pesticide use. They found that the widespread use of GM seeds has decreased the use of insecticides, but has increased the use of herbicides, as weeds become more resistant.
GM crops have been a heated topic of discussion because of the ongoing debate about the risks to human and environmental health. Monsanto claims that GM food will feed the world, while at the same time reducing pesticide use. But according to new research, overall herbicide use has risen dramatically over the recent years, causing severe environmental damage.
New study reveals horrible truth
University of Virginia economist, Federico Ciliberto, led the study alongside Edward D. Perry of Kansas State University, David A. Hennessy of Michigan State University, and GianCarlo Moschini of Iowa State University.
Together, the four academics analyzed annual data from more than 10,000 soybean and maize farmers in the U.S. from 1998 to 2011. They gathered 14 years of farm-level data from farmers all over the U.S., making this the largest study on GM crops and pesticide use to date. All previous studies have been limited to one or two years only.
As stated by Ciliberto, the fact that they have followed farmers for 14 years makes this study unique. They performed repeat observations of the same farmers, and could clearly see when they adopted GM seeds and how that changed their use of toxic chemicals.
As reported by Popular Resistance, genetically engineered crops account for more than 80 percent of maize and soybean crops planted in the U.S. since 2008. Maize seeds are generally modified with two genes: one of them kills insects that eat the seeds, while the other makes the seeds resistant to glyphosate, a herbicide commonly used in weed killers like Roundup.
The authors of the study found that GM maize farmers used 1.3 percent fewer herbicides over the period studied, while the herbicide use of GM soybean farmers increased by a whopping 28 percent compared to their non-GM counterparts.
Herbicide use has dramatically increased in the past five years
Ciliberto and his colleagues attributed the increase to the rise of glyphosate-resistant weeds, which cause farmers to use more and different combinations of toxic chemicals that may harm biodiversity and increase water and air pollution.
Maize farmers have been spared from the same level of herbicide resistance, because they have not adopted genetically modified crops as quickly as the soy industry.
Despite the decrease in herbicide use in the maize industry, experts believe weed resistance is a growing problem for both soy and maize. They found evidence that during the last five years of the study, both maize and soybean farmers dramatically increased their herbicide use.
“In the beginning, there was a reduction in herbicide use,” Ciliberto said, “but over time the use of chemicals increased because farmers were having to add new chemicals as weeds developed a resistance to glyphosate.”
Furthermore, the researchers reported that maize farmers using GM seeds cut down insecticide use by 11.2 percent; insects don’t seem to develop a similar resistance. This is mainly due to federal regulations that require farmers to have “safe havens” in their fields. These safe havens are free of GM crops and create a safe home for insects and worms.
These insects don’t develop resistance, and breed with other insects in the rest of the field, which helps to prevent the development of resistance genes.
While insecticide use may be decreasing, these findings clearly show that GM crops negatively impact the environment. They have increased herbicide resistance, which means that more chemicals are being sprayed that seep into the soil and water and contaminate the local ecosystem and our food chain.
Ciliberto said that he was surprised by the extent to which U.S. herbicide use has increased in recent years, and is deeply concerned about the potential environmental impact this may have.
Using a measure called the environmental impact quotient (EIQ), the authors concluded that the adoption of genetically modified soybeans correlated with a massive adverse impact on the environment caused by increased herbicide use.
To do your bit and help save mother earth, start growing your own chemical-free food. It’s fun, cheap and environmentally friendly.
Sources for this article include: