News on GMOs

There have been a couple news items regarding genetically engineered crops.  

The first is a new paper published in Science Advances (co-authored by a couple agricultural economists, David Hennessy and GianCarlo Moschini).  The authors used a large scale survey of corn and soybean farmers to determine the impact of biotech crops on pesticide and herbicide use.  By and large, I'd say the research confirms what has become the scientific consensus on these issues: 

Over the period 1998–2011, our results show that GE variety adoption reduced both herbicide and insecticide use in maize, while increasing herbicide use in soybeans. However, weighting pesticides by the EIQ [environmental impact quotient] lowers the difference in herbicide use by GT soybean adopters (such that the estimated average impact over the study period is statistically indistinguishable from zero). Adoption of Bt maize, on the other hand, is associated with a clearer decline in insecticide use.

This article at NPR interviewed weed scientists Andrew Kniss about the study, and he is critical of the use of EIQ. I believe his argument is that a proper toxicity-adjusted herbicide use might have shown a reduction in herbicide use in soybeans from adoption of GE.   Note also that several of the same authors published a related paper a few months ago showing adoption of GE herbicides led to higher rates of adoption of conservation tillage and no-till.  

In other news, Mark Bittman has an editorial today in the New York Times on the new GMO labeling laws.  I often disagree with Bittman, but I was pleased to see that he had a reasonably accurate portrayal of the science on GMOs:

These foods produced with G.M.O.s have not been found to be harmful to people who eat them. (This isn’t to say they won’t be; our system for declaring products safe leaves much to be desired.) In some instances, the technology has yielded great medical benefits and will certainly lead to more. In industrial agriculture, the technology has led to lower applications of insecticides. But it has also encouraged the growth of weeds that have become resistant to herbicides after years of exposure, often forcing growers to turn to more and different herbicides in a cycle of chemical warfare.

He goes a bit polemical at the end (as if organic and local producers don't use "chemicals" to control bugs and weeds).  And, he goes a bit off the rails in the next paragraph:

Another problem is that by simplifying the growing of almost unimaginably large tracts of crops, especially corn and soybeans, G.M.O.s have become an indispensable crutch for the fertilizer- and pesticide-dependent monoculture that is wrecking our land and water and generating the execrable excess of corn- and soy-based junk food that is sickening our population and decreasing our life spans.

The implication seems to be without GMOs we wouldn't have as much corn and soy.  But, here's data from USDA on the number of acres in the US planted to corn over time.  

Yes, there has been an increase in corn acres since the mid 1980s, but biotech corn didn't start being grown in earnest until about 2005 (that's when more than half of US corn acres were biotech), and of course we had ethanol policies emerge in the mid to late 2000s, which promoted movement to corn acres too.  

More important, look at the data prior to 1950.  We were planting more corn then than now.  But prior to 1950, there was no biotech.  Use of hybrid corn and "synthetic" fertilizer didn't begin in a big way util the late 1930s.  And, yet in the 1920s, we planted more corn than we do now.  So much for the "chemical warfare", "fertilizer-dependent" story that explains our "monoculture" production system.  That is, the figure above suggests Bittman might want to rethink some of the key underlying economic reasons why we plant hardy, easily storeable, easily transportable crops like corn.  

In any event, Bittman's larger point is that he hopes the new mandated QR codes will be used to disclose all kinds of other information about food:

Where are the ingredients from? Were antibiotics routinely administered to animals? What pesticides and other chemicals were used, and do traces of these chemicals remain? Was animal welfare considered, and how? What farming practices were used? How much water was required? Let’s really get down to it. Were the workers who sweated to put food on my table paid at least minimum wage? Did they get health benefits? Overtime? Were they unionized? Protected from pesticide exposure?

I suspect there are some people who would value such information.  However, my research shows most people mainly care about something much more basic: : is this food tasty, safe, healthy, and affordable?