By ANN HINCH
Assistant Editor

WASHINGTON, D.C. — Fourteen years after genetically engineered (GE, sometimes called GMO) seed went on the market, such crops are grown on more than 80 percent of corn, soybean and cotton acres in the United States, which is more than half all planted acres. But not much is known about their socio-economic effects on farms and farmers themselves.

According to a National Research Council (NRC) study released last week, what does concern some scientists is that GE crops’ effectiveness could be waning thanks to evolving weed and insect resistance to the specific traits designed to defeat those pests.
Increasing glyphosate resistance in particular stands out, since this is the most common broad-spectrum weed killer used around crops, mainly soybeans, in the United States. To lose glyphosate could mean a return to weed control considered more environmentally harmful.

“In general, we find that GE crops have had fewer adverse effects on the environment than non-GE crops produced with conventional farming methods,” said L. Lareesa Wolfenbarger.

Wolfebarger is an associate professor in the University of Nebraska Department of Biology and member of the NRC committee formed to study GE crop effects on farm-level technology and sustainability.
Herbicide-resistant crops, she said, have gone hand-in-hand with increased conservation tilling practices to reduce soil erosion and improve water quality during the past decade or more. David Ervin, committee chair and a professor in economics and environmental management at Portland State University, said this is not meant to imply all GE growers practice better conservation than all non-GE growers.

“We worded this very carefully in our findings, that these (practices) were replacing non-GE conventional farming methods,” he said.
Because agriculture is the largest single source of surface water pollution in this country, Wolfenbarger said, better conservation practices may be the most significant contribution of GE crops to sustainability.

She said the study examined the effects of approved use of glyphosate, and that water contamination is restricted to it being sprayed too close to waterways – which is not a federally approved use.

Glyphosate, she said, is attributed with less toxicity for humans and wildlife than other herbicides. But there is evidence at least 10 U.S. species have developed resistance to the weed killer – she explained this might encourage a return to more tillage and use of more toxic herbicides.

Insect-resistant GE crops such as corn and cotton are designed to produce bacillus thuringiensis, or Bt, a bacteria that kills susceptible pests feeding on the plants. Wolfenbarger said use of Bt crops has shown the trait may be favorable to plant-beneficial insects that used to be hurt by broader-spectrum insecticides.

After 14 years, there is evidence at least two species of pests have developed a resistance to the Bt trait, too. The study noted so far, the economic impact of this seems minor.

Crop economics
Non-GE growers worry about cross-pollination between their crops and geographically-close GE crops. The report stated breeding with wild or weedy relatives doesn’t happen because GE corn and soybeans do not have weedy relatives in the U.S., and for cotton this is only a “local” problem. But, potential of “gene flow” to cultivated non-GE crops is a concern, especially as use of GE increases.

At one point, the study noted use of GE crops may have helped organic growers develop a niche market for sales of their crops, since they appeal to consumers who don’t want GE food. Someone with an organics organization at the NRC press conference, however, wanted to know if the researchers had taken into account how much more organic growers now have to spend on extra testing and certification that their crops are not being cross-pollinated.
Ervin admitted there is no good data on these costs. Wolfenbarger did say, however, the study urges industry to find ways to reduce potential cross-pollination that won’t impose additional costs on the farmers themselves.

Another area for which there was little existing data are GE crops’ socio-economic effects on all farmers. NRC committee member Raymond Jussaume Jr., professor and chair of the Washington State University Department of Community and Rural Sociology, said this is particularly noticeable when it comes to such effects on non-adopters of GE: livestock producers and organic and other non-GE growers.

There are some benefits easily observed, said Ervin – reduced farm expenses for fuel and chemicals, increased worker safety, reduced losses to insects and weeds and more time to devote to other aspects of farming or even to working off the farm. “These are not just financial benefits,” he said.

He agreed with Jussaume, however, that there’s not enough credible data on how non-GE farmers are affected. “We’ve had this first era of GE crops,” he said, “but now is the time to take stock of what’s happening and what the potential is.”

Jussaume briefly addressed how the structure of the seed industry has changed over the years, noting that by 2007, 70 percent of U.S. corn acres and 15 percent of soy were planted with seeds from only four companies. To be fair, he said consolidation of this industry began before the planting of GE crops.

According to Ervin, right now there is no good evidence on what this consolidation means for any farmer – “Frankly, it has not been studied well enough,” he said. He did say the NRC understands that farmers have trouble finding good, viable cultivars of non-GE seed.

Needs
The NRC – which, unusually, funded its own study – came to a few basic conclusions in this report. First, it said stakeholder groups need to document the weed resistance problem to glyphosate and develop cost-effective methods to curb it. The specific effect on water quality of GE crops should also be documented, ideally by the U.S. Geological Survey and associated agencies.

Next, there needs to be a better job done of monitoring and assessing the effect of GE crops, overall. Over the last 5-8 years, the report noted, various parties of interest seem to have lost a handle on how GE technology is being used and its environmental impacts.

The report also suggests better management of GE crop and herbicide rotation might help delay non-crop plant resistance to glyphosate. Wolfenbarger said other factors that might help are different application methods and equipment and harvesting alterations.

For these crops to promote sustainable agriculture, the report also said there needs to be a stronger public-private collaboration – including farmers themselves – in developing the “next generation” of GE crops, for both major commodities and less widespread crops that may use the technology. There is some technology, the scientists noted, that private companies alone will probably not invest enough in to move the research along as quickly as farmers would like (such as, say, drought tolerance).

To view or order the NRC report, visit www.nap.edu/catalog.php?record_id=12804