The appearance here of weeds resistant to glyphosate, the herbicide commonly used in conjunction with soybean varieties that are genetically modified to tolerate it, may force Argentine agriculture to heed environmentalists’ decade-long warnings against favoring monoculture over crop rotation. Since Argentina authorized commercial plantings of genetically modified soy in 1996, soybean cultivation here has grown from six million hectares to 20 million hectares, and now accounts for half of the country’s cropland under cultivation. The soy, introduced by Monsanto under the name Roundup Ready, allowed farmers to kill weeds without harming the crop, use no-till cultivation and expand to lands previously considered marginal. Increasingly, critics including environmentalists, indigenous-rights activists, academics, and in some cases farmers themselves have warned that the monocrop agriculture... [Log in to read more]