Increased yields are just ONE benefit for SOME crops. Today’s GM crops are basically developed to fight bugs and weeds, the bane of farmers, and a drag on crop yields.

As Sara notes in her post, research is underway to address issues of salt tolerance and better nitrogen utilization. And drought tolerance improvement has already been realized in corn. These changes will likley allow future farmers to grow crops on marginal land, or to better adapt crops to the changing climate.

I appreciate Sara’s thoughtful comments — she’s a scientist, and I’m not. I would encourage anyone who wants to wade into this issue and make their own decision, to visit http://www.isaaa.org/kc/default.asp (paste this link into your browser) to learn more about the work that’s being done around the world to help farmers, particularly those in developing countries, have access to modern tools of agriculture.

I cannot find the original research article online, but what I have been unable to unearth does lend creedence to a yield decline in Roundup Ready GMs. This is in part explained by the chemical action of the Roundup itself, which can alter the nutrient uptake ability of the plant, even if the plant is engineered to be resistant to the killing action.

The important thing to realize is that this is not an indictment of the GM process itself. It is a strong caution to the industry however, about evaluating the big picture, and total production when we use GM.

One other real phenomenon is the genetic progress made in breeding conventional varieties while the modified strain is being tested. In species where there is still much genetic progress to be made by traditional selection, the base yield may, in fact, increase more in the time lag than the modification causes in the original crop. That same modification, once proven, could theoretically be made in the later generation genetic stock to bump the yield further.

I have seen much very convincing research on modifications such as salt tolerance and nitrogen utilization that show yield increases and/or fertilizer need decreases compared to conventional varieties.

Neither sweeping generalization that “GMOs will cause the end of the world” nor “GMOs will solve all our problems” are accurate. Genetic modification is a useful technology, but must be evaluated thoroughly and honestly and used wisely in the larger context.