The impacts of genetically engineered crops on the surrounding environment have been examined and released in the June 2011 report issued by ISB News Report. Overall, the review found that currently commercialized GE crops have reduced the impacts of agriculture on biodiversity through enhanced adoption of conservation tillage practices, reduction of insecticide use and use of more environmentally benign herbicides. Increasing yields also alleviate pressure to convert additional land into agricultural use.
According to the findings, studies of genetic diversity in cotton and soybean in the U.S. both concluded that the introduction of GE varieties was found to have little or no impact on diversity. “From a broader perspective, GE crops may actually increase crop diversity by enhancing underutilized alternative crops, making them more suitable for widespread domestication,” according to the report.
In terms of farm-scale diversity, the findings showed that, “… in general, few or no toxic effects of Cry proteins on woodlice, collembolans, mites, earthworms, nematodes, protozoa and the activity of various enzymes in soil have been reported. Although some effects, ranging from no effect to minor and significant effects, of Bt plants on microbial communities in soil have been reported, they were mostly the result of differences in geography, temperature, plant variety, and soil type and, in general, were transient and not related to the presence of the Cry proteins. Crop production practices also have significant effects on the composition of weed communities.”
One negative attribute the study found was related to the loss of natural habitats. “The most direct negative impact of agriculture on biodiversity is due to the considerable loss of natural habitats, which is caused by the conversion of natural ecosystems into agricultural land. Increases in crop yields allow less land to be dedicated to agriculture than would otherwise be necessary. A large and growing body of literature has shown that the adoption of GE crops has increased yields, particularly in developing countries. A review of the results of global farmer surveys found that the average yield increases for developing countries range from 16 percent for insect-resistant corn to 30 percent for insect-resistant cotton, with an 85 percent yield increase observed in a single study on herbicide-tolerant corn.”
To read the full report, click here.