Comprehensive Study into Non-GMO Environmental Impact
A team of researchers, at Midwest academic institutions, has published the results of a new analysis, comparing herbicide and pesticide usage in GE versus non-GE crops. The paper boasts a more robust method and dataset, versus much of the existing work. It is also set apart by the large temporal span of the surveys it analyzed—ranging from 1998-2011—versus prior research, which generally considers only a few years of data. Published in the journal Sciences Advances last month, the results found that GE, glyphosate-tolerant (GT) soybeans led to a raw increase of 28% in herbicide usage, over the timeframe examined, relative to non-GE varieties. GT maize herbicide raw usage decrease by 1.2% on the other hand, and insecticide-tolerant (IT) maize saw insecticide applications fall 10.4%.
Two other important factors were considered in the paper. First, the authors analyzed the Environmental Impact Quotient (EIQ), which weights combinations of different herb- and pesticides by degree of environmental impact. An effectively 0% difference was observed in EIQ-adjusted herbicides between GT and non-GT soybean adopters. GT corn saw an EIQ-adjusted decline of 9.8% herbicide usage, while IT corn saw EIQ-adjusted pesticides fall the same 10.4%. The paper also noted that, since the inception of GE crops, herbicide usage has been creeping persistently upwards in both corn and soybeans, while pesticides, conversely, have been steadily falling.
The latest results from Sciences Advances suggests that the environmental impact of GT and IT products has been net-neutral (soybeans) to net-positive (corn). Critics point out, however, that EIQ measures are often an inaccurate and cumbersome metric, and that pending issues, such as increasing weed and pest-resistance, are unquantifiable, and loom on the horizon. (NPR; Science Advances).
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