|Corn growing in Ohio by Graylight (Flickr) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)]|
via Wikimedia Commons
The results of a unique US agronomic study have been released. Two different commercial maize crops grown in fields with different management histories were tested for composition. One crop was a GM herbicide-tolerant variety in a no-till field treated with glyphosate (Roundup) for the past 10 years. The other was a conventional variety in a field which hadn't been sprayed with Roundup during the previous 5 years. The two fields were separated by a fence. Environmental stresses on the crops were not unusually high that year.
Compositional analysis was by the 'gold standard' technique of chromatographic separation followed by mass spectrometry to identify the components. (Note that such analysis identifies specific substances, not the broad nutrient categories routinely used to assess the animal feeding value of crops.)
As expected, the GM crops had accumulated glyphosate levels equal to the recently set US maximum residue level. Also as expected (because glyphosate is known to bind to certain substances making them unavailable) the GM crop had lower levels of essential mineral nutrients.
Because the two crops were genetically different cultivars, it would be unlikely for their nutrient to be the same. However, the extent of the difference was extreme: with one single exception out of the fourteen minerals measured, the conventional maize had levels six to four-hundred times higher than the GM crop.
Even more unexpected was the discovery of high readings of formaldehyde in the GM maize. None was detected in the conventional one.