Almost half of all US cropland was planted to genetically engineered (GE) crops in 2009. The report said that GE crops have provided many farmers with economic and environmental benefits, due to less pesticide use and lower production costs, but the NRC warned that GE crops that are resistant to glyphosate – the herbicide in Monsanto’s Roundup Ready product – could lose their effectiveness as new weeds evolve to withstand it.
Professor of environmental management and economics at Portland State University, and chair of the committee that wrote the report, David Ervin said: "Many American farmers are enjoying higher profits due to the widespread use of certain genetically engineered crops and are reducing environmental impacts on and off the farm.
"However, these benefits are not universal for all farmers. And as more GE traits are developed and incorporated into a larger variety of crops, it's increasingly essential that we gain a better understanding of how genetic engineering technology will affect US agriculture and the environment now and in the future. Such gaps in our knowledge are preventing a full assessment of the environmental, economic, and other impacts of GE crops on farm sustainability."
In particular, the NRC raised concerns about reliance on Roundup Ready crops for weed control.
“The repeated use of glyphosate as the only weed-management strategy favors the evolution of glyphosate-resistant weeds,” it said. “…To limit the evolution of glyphosate-resistant weeds, farmers of herbicide-resistant crops should incorporate more diverse management practices, such as herbicide rotation and tank-mixes of more than one herbicide.”
Developing new benefits
The report went on to say that research institutions should be eligible for government support to develop GE crops that could provide valuable benefits, but that have “insufficient market potential to justify private investment.”
Among such GE crops, it lists plants that could be bred to be resilient to changing climatic conditions, plants with reduced water requirements, plants with added nutritional value, and plants that could produce their own nitrogen, thereby reducing pollution caused by fertilizers.
Responding to the report, the Center for Food Safety’s executive director Andrew Kimbrell said that his organization has long maintained that GE crops are unsustainable, and called the NRC’s report “a small step toward acknowledging the truth of this critique.”
“Its recommendations fall far short of adequately addressing the problem,” he said. “…The costs of what the NRC calls ‘excessive reliance’ on Roundup Ready technology are legion…In the end, the NRC makes too much of short-term benefits of certain GE crops, and fails to appreciate the inherent unsustainability of the pesticide-promoting technologies being offered by the industry. In addition, there is too little concern for the many adverse impacts of seed industry concentration and seed patents on farmers’ welfare.”
A summary of the report can be found online here.