ST. LOUIS - The global use of genetically modified crops, which allows farmers to plant using less herbicide and without tilling the soil, is significantly reducing greenhouse gas emissions, according to a new study.
In 2005, the impact in reduced carbon dioxide emissions was the equivalent of removing nearly 4 million average family cars from the road, said the study by Graham Brookes and Peter Barfoot of PG Economics Ltd., a British consulting firm. The study was commissioned by Monsanto Co. of Creve Coeur, Mo., the world's leading provider of biotech crops, and published in the peer-reviewed journal AgBioForum.
Genetically modified, or GM, soybeans, corn, cotton and canola were planted on 215 million acres by 8.5 million farmers in 2005, the study said. These crops ward off certain pests and withstand applications of glyphosate herbicide, a weed killer that is less environmentally damaging than other chemicals.
Benefits of no-till
The biggest environmental benefit of these crops, according to the study, comes when they are used to enable no-till farming. Growers who use that technique don't plow the ground; they plant through the organic material left from a prior crop.
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Plowing allows naturally occurring carbon dioxide to escape into the air, contributing to greenhouse gas buildup.
Farmers in North and South America rapidly have adopted no-till farming in conjunction with GM crops, the study found. In 2005, this practice left in the ground 2.9 million kilograms of soil carbon that would have been released through plowing - an amount equal to the emissions of 3.6 million cars.
"No-till farming is nothing new. Farmers have been trying (it) for many years," Brookes said. But the approach doesn't work well with conventional crops, leading many growers to abandon it.
Further carbon dioxide savings come from reduced use of fossil-fuel-burning farm vehicles. The reduction includes the use of plow equipment, as well as vehicles used to spray pesticides needed on conventional crops.
Since their introduction in 1996, GM crops have saved farmers 441 million gallons of fuel, which led to a 4.6 billion kilogram reduction in carbon dioxide emissions, the study said.
Vic Miller, chairman of the U.S. Grains Council, to which Monsanto and other biotech seed companies belong, said he's impressed with the results. He's been using GM crops on his 3,600-acre Iowa corn and soybean farm since 1996.
"It's put more money on my bottom line, year after year. And it's allowed me to reduce chemical and pesticide use in my operation," he said. "I'm one of the first environmentalists, because I have to live there. I drink the water and walk on the soil, and I don't appreciate having to use products that have the skull and crossbones on them."
