Ecological impacts of genetically modified crops. Experiences from ten years of experimental field research and commercial cultivation | Impacts ecologiques des cultures genetiquement modifiees. Experiences de dix ans de recherche experimentale en champ et de culture commerciale

The global area planted with genetically modified (GM) crops has consistently increased each year since GM crops were first commercially cultivated in 1996 reaching 90 million hectares in 2005. GM crops are currently grown by 8.5 million farmers in 21 countries, where 90% of the farmers using the GM technology live in developing countries. Five countries (USA, Argentina, Brazil, Canada and China) are growing nearly 95% of the total area of these crops and there are four main GM crops that are grown worldwide. Soybean is the principal GM crop occupying most of the global area, followed by maize, cotton and oilseed rape. Herbicide tolerance is the dominant trait that is deployed in all four crops, while maize and cotton are the only two insect resistant GM crops commercialized. Concerns have been raised that the commercial cultivation of GM crops could result in adverse effects on the environment. Agroscope Reckenholz- Taenikon Research Station ART was commissioned by the Swiss Expert Committee for Biosafety to review the scientific knowledge on environmental impacts of GM crops deriving from ten years of worldwide experimental field research and commercial cultivation. The sources of information included peer-reviewed scientific journals, scientific books, reports from countries with extensive GM crop cultivation, as well as reports from international organizations. For some of the questions addressed only limited infor mation was available from commercial cultivation. Therefore most chapters of the study include to some extent scientific data deriving from large-scale experimental field research. The authors recognize that results from large-scale cultivation systems, as often characteristic in the countries growing GM crops, have to be transferred with care to small-scale agricultural systems like in Switzerland. However, we believe that the worldwide scientific knowledge and the existing practical experiences should be taken into account for future decision making when discussing potential risks of field releases of GM crops in Switzerland. [...]When discussing the risks of GM crops, one has to recognize that the real choice for farmers and consumers is not between a GM technology that may have risks and a completely safe alternative. The real choice is between GM crops and current conventional pest and weed management practices, all possibly having positive and negative outcomes. To ensure that a policy is truly precautionary, one should therefore compare the risk of adopting a technology against the risk of not adopting it. We thus believe that both benefits and risks of GM crop systems should be compared with those of current agricultural practices.