Genetically Modified Corn and Soy Breed Superweeds
The law of natural selection dictates that species will adapt, over time, to a changing environment. And unfortunately for American farmers who rely on GM crops, it seems that some of the world’s most invasive weeds are following nature’s laws to the letter when it comes to competing with genetically modified soybeans and corn.
Genetically modified corn and soybeans developed by Monsanto in the 1990s to be resistant to the synthetic herbicide glyphosate (better known by Monsanto’s trademarked name for the weedkiller, Roundup), have nearly taken over the American rural landscape. More than 80 percent of soybeans and more than 70 percent of corn produced in the United States are the genetically modified, herbicide-resistant variety.
And not without reason. Genetically modified soybeans and corn make it possible for farmers to plant their crops without tilling the soil to kill weeds first. With Roundup Ready crops, farmers can simply douse an entire field in glyphosate, then plant their seeds. According to the corporate producers of GM corn and soy, this method of farming is actually better for the environment than traditional large-scale farming methods. Why? Because no-till farming reduces the runoff of fertilizer and pesticides into water systems and prevents degradation and erosion of the soil.
But environmentalists and natural food advocates have been wary of GM foods since their introduction. Some scientists have argued for years that companies like Monsanto don’t do enough to test the safety, or the environmental impact, of their genetically modified crops before putting them on the market.
Though there is still scant scientific evidence regarding the long-term effects of genetically modified foods on human health, there have been a few animal studies on the effects of certain types of genetically modified foods that may be cause for concern. In 2008, an Austrian study indicated that eating GM corn may cause a decline in fertility in mice. And in January of this year, a study published in the International Journal of Biological Sciences warned that a comparative analysis of Monsanto’s own data on the effects of genetically modified corn indicates that a diet heavy in GM corn may cause organ damage in rats.
Even as the safety of herbicide-resistant GM food crops continues to be called into question by studies such as these, it now appears the very selling points that bioengineering companies used to convince farmers to switch to genetically modified crops, may no longer apply.
In a world where nearly every field for miles and miles is sprayed every spring with a uniform fog of glyphosate, the weeds GM corn and GM soy were developed to fight have done the only thing they can to survive — they have adapted.
According to a report on genetically modified foods recently released by the National Academy of Sciences Board on Agriculture and Natural Resources, up to nine species of invasive plants that interfere with food production are now naturally genetically resistant to Roundup. The report notes, “the nearly exclusive reliance on glyphosate for weed control, a practice accelerated by the widespread introduction of glyphosate-resistant crop varieties, has caused substantial changes in weed communities.”
Which means that some farmers who are already paying premium prices for the Roundup Ready seeds that are supposed to keep them from having to till their soil to kill weeds must now till anyway. Farmers who have depended on Roundup and Roundup Ready crops for years to reduce their use of other, more toxic herbicides, are finding they must now add those other herbicides on top of a generous application of glyphosate.
Just over a decade after their development, these artificially created, genetically modified plants that were meant by their creators to permanently transform agriculture are already in danger of being made obsolete by nature’s own power to rearrange genes. This points us to the obvious question: if genetically modified crops, designed to resist herbicides, provide such a brief window of benefit to farmers, why use them at all?
There are heirloom varieties of corn and soy that have been grown by organic farmers for literally hundreds of years — foods that were developed through the very old-fashioned, time-tested biotechnology called crossbreeding — foods that have proven their safety by safely feeding generations of people. Though heirloom crops often require more individualized attention than conventional commercial crops to thrive, some of them are surprisingly resistant to various problems and pests if they are given the right nutrients in the right environment.
It is absolutely true that the world needs innovative scientific solutions to provide our growing global population with sustainable food. But instead of trying to best nature, we may do well to seek new ways to thrive by nature’s own rules. In nature, variety is the genuinely vital spice of life. Species thrive in nature by harnessing the power of diversity, capitalizing on the constant natural variations on their own genetic codes to adapt and compete in an ever-changing environment.
A tiny variation in the thickness of a corn stalk or the taste of a leaf may hold the key to successful competition in a new set of circumstances. And in nature, natural selection allows those traits to spread as needed from one generation to the next. The traditional crossbreeding techniques used by people for thousands of years, sped and guided, but did not hamper this process. We changed the plants, but also left them free to keep changing.
Nature’s rules do not produce vast, miles-wide monoculture stands of identical clones of a single plant, all bearing a single set of genetic instructions, for a very good reason: that model of life is not sustainable on a changing planet. Life needs genetic variation to thrive. By trying to control the genetic code of our food plants so tightly, making sure every planted, patented seed bears the proper modified genes, we actually cage and cripple them. They cannot adapt without our assistance.
But the weeds and pests that threaten our food supply — wild creatures outside our genetic control — still can. And they have. Will we learn from it?
Corn Field photo by Paranoid, from Wikimedia Commons. Public domain.