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NC State Extension

Do GMOs Contribute to Monoculture?

Monocultures are prevalent in agriculture in the developed world and are commonly used in conventional, organic and bioengineered agriculture (GMOs). The main reason farmers often use monocultures is due to mechanization, particularly mechanical harvesting. Imagine a field where you intercrop peanuts with corn. Your corn would like mature first and you would have to run a combine (corn harvester) over the peanuts to harvest the corn. This would certainly damage the peanuts. In addition, crop yields on a given area of land are almost always higher in monoculture than in an intercropping system. Imagine again a field of intercropped corn and peanuts. The corn would be much taller and would reduce sunlight available for peanuts. Monocultures were heavily in use well before bioengineered crops, and there are very practical reasons why many growers use monoculture. Most growers do rotate crops to create biodiversity in time as explained in this article from Washington State University.

Many of the traits that have been made available through bioengineering would work just as well, or perhaps better in intercropped systems as they would in monocultures. Imagine our corn and peanuts intercropped system again. If you had an insect or disease that was affecting the corn and were applying a synthetic or organic insecticide or fungicide, you would likely spray both of the crops. If the corn was bioengineered to be insect or disease tolerant you might be able to not only avoid spraying the corn, but also avoid unnecessarily spraying the peanuts. Bioengineered traits such as reduced toxins or increased nutritive value would work equally well in monoculture or intercropping.

The bioengineered trait that might be mostly suited to monoculture versus intercropping would be herbicide resistance. For a bioengineered herbicide trait to work in an intercropped system, all of the crops would have to tolerant of the same herbicide. In our corn and peanut example, we could use a corn that was glyphosate tolerant, but there is no glyophosate tolerant peanut. Spraying the corn with glyphosate in field with intercropped peanuts would damage the peanuts. Alternatively you could substitute glyphosate tolerant soybeans for the peanuts and use the trait in an intercropped system.