"Genetically modifying crops such as corn and soybeans to tolerate exposure to glyphosate-based herbicide has made it possible for many farmers to mechanically till their fields less often, which reduces soil erosion, as well as farming costs.
Many farmers no longer need to disturb the soil to kill weeds, because they can spray herbicide directly on their fields without harming their genetically modified crops.
Genetically modifying crops with a gene from a soil microorganism to make a natural insecticide has allowed many farmers to reduce their use of synthetic pesticides that kill beneficial insects such as honey bees.
"Genetically modified crops have had less adverse effects on the environment" than their conventional relatives. They have spread rapidly since Monsanto Co.'s herbicide-tolerant soybean was introduced in 1996: About 80% of the soybeans, corn and cotton grown in the U.S. are now produced from genetically modified plants."
Genetically Modified Crops Get Vote of Approval - WSJ.com.