The consequences of genetically modified crops for organic farming in Denmark

A report from DARCOF analyses the potential risks of plant biotechnology development for organic production in Denmark. The main objective is to compile existing knowledge concerning the effects of genetically modified plants (GMP) and crops in order to propose concrete measures to avoid or to minimize the risks of GM-contamination.

The work leading to the report has been carried out by a group of experts with experience in organic farming, agricultural production, regulation and control, plant biology, plant biotech, modelling and risk assessment of ecological, agricultural and toxicological effects of GMP.

The central issues described are: the expected biotechnology crop development, principles for organic farming, farm practices including a discussion of the risk of GMP contamination from import of non-organic seed, feed and manure, the risk of dispersal by pollen and seed to the field, and the current and future legislation and regulation in the EU.

By April 2001 a total of 1660 field release trials with approximately 60 plant species has been made in the EU; the majority was performed with genetically modified maize, oilseed rape, beet and potato. The involved traits were herbicide-, insect-, nematode- and virus-resistance, male-sterility and changed metabolic compounds. To this day, only 4 cultivars of maize, 1 soybean, 2 oilseed rape and 1 chicory have been approved for marketing in the EU. Of these, 1 maize, 1 soybean and 1 oilseed rape are approved for import only, while 1 oilseed rape and the chicory are approved for seed production only. There has been a limited production of GM-maize in Spain, Germany and France. Presently, no GMP cultivars are approved for cultivation in Denmark, but within five years, genetically modified fodder- and sugar beet; oilseed rape and maize are expected to be introduced to Danish agriculture.

The number of organic farms and the total organic farming area has increased over the latest years. However, this development seems to be quite dependent on the type of farm (dairy, pig or arable). In general GMO's are not wanted in organic farming, and by definition organic farmers do not want to rely on GMO in their production. However, the development of organic farming systems is, at present, to some extent dependent on the use of non-organic seed, feed and nutrients. With increased use of GM-crops in conventional farming systems, it is expected that the risk of GM-contamination will increase by the use of non-organic products. It is therefore concluded that the development of organic farming relies on the availability of GMO-free organic seed, feed and nutrients as well as on the possibility to sell organic products. At the moment the availability of seed of pulses, white clover, alfalfa, beets, vegetables and hybrid-rape is insufficient to supply the demand. Some of these species are cross-pollinated and they are characterised by a high risk of contamination by GMO.

The most evident way of reducing this man-made (controlled) GMP-contamination is to exclude the use of non-organic products in organic farming. However, under the prevailing conditions this will affect the organic farming systems dramatically. Instead, it is recommended that projects to develop organic seed in species, where the supply is insufficient, should be initiated, and that organic production systems for protein crops to eliminate the use of soybean should be developed.

For most out breeding species, the majority of pollen is dispersed within 100 to 200 meter from the field. Pollen of some species, such as oilseed rape, beet and maize, can, to some extent, disperse by wind or bees to distances up to 1 to 3 km. Some mainly inbreeding species, such as barley, wheat, pea, broad bean and potato, have a low risk of GM-dispersal and hybridisation. The group of high-risk species for GM-contamination consists of oilseed rape, red clover, white clover, alfalfa, maize, perennial forage grasses and rye. Oilseed rape is especially a problematic species because hybrids between rape and field cabbage or wild radish easily establish, are quite common and may become sources for further dispersal of GM-traits. Seeds of some grain crops survive for less than 1-2 years in the soil and consequently represent only a minor problem. Seeds of oilseed rape, beet, perennial forage grasses, black medick, white clover and red clover however can survive for 5 to maybe 20 years. Therefore need precautions need to be taken to secure that GM-types do not survive.

The consequences of biological dispersal of GMP to organic fields may be minimised by modified cultivation measures. It is suggested that isolation distances between GM-crops and organic fields are established similar to those required for seed production. For dispersal-critical GM-crops, such as oilseed rape, beet and maize, the isolation distance should probably be increased (not be less than 2 to 3 km). This will not completely prevent GMP dispersal by pollen, but will reduce the extent greatly. For both practical and political reasons longer isolation distances or GMP-free regions are perhaps not realistic in Denmark. The use of protective safety zones around organic fields is another possible way of reducing the risk of GM-pollen dispersal. Research and modelling of crop specific requirements for this need to be done. During crop rotation, it may, to some extent, be possible to use low-risk crops, which have no or only little risk of GM-contamination by pollen. Based on results from specific farm monitoring for detection of GM-hybrids and GM volunteer seed, the transition time for soil, used for GM-crop production, to organic cultivation should probably be extended for critical crops. Different cultivation techniques could also be used to reduce the GM seed bank in the soil and volunteers. Finally, it is suggested that organic farmers actively take position on the use of a concrete threshold limits for GM-content in organic products.

Gösta Kjellsson & Birte Boelt (eds.) 2002. The consequences of genetically modified crops for organic farming in Denmark . FØJO-rapport no. 16. 136 pp. Download Danish version (pdf 1.500 kb)

A full article in the late autumn of 2002 be submitted for publishing in a reviewed journal.


New research
Following the investigations a number of research projects on organic seed production and development has been established. The research intends to improve the performance and the quality of organic seeds, and - at the same time - to provide organic farming with tools for protection against contamination by GMO.

Current research in organic seed production and development