Source: DEFRA

A study published today has shown that the abundance of wildlife differs between GM herbicide-tolerant winter oilseed rape and its conventional counterpart.

Growing herbicide-tolerant GM winter oilseed rape resulted in the same overall numbers of weeds as conventional winter oilseed rape but there were fewer broad-leaved weeds in the GM crop and more grass weeds. Flowers of broad-leaved weeds provide food for insects, and fewer bees and butterflies were found in the GM crop compared to the conventional crop.

Seed numbers of broad-leaved weeds were lower and numbers of grass seeds were higher in the GM crop. Weed seeds are an important food source for other wildlife and seeds from broad-leaved weeds feature strongly in the diet of farmland birds.

Some beneficial soil insects were found in greater numbers in the GM crop. Fewer differences between GM and conventional winter oilseed rape were found in the number of other insects, slugs and spiders compared to the other three crops studied in the farm scale evaluations.

The researchers stress that the differences they found are not a result of the way in which the crop has been genetically modified. They arose because this GM crop gave farmers taking part in the trial new options for weed control. That is, they used a different herbicide and applied it differently.

The researchers also stress that the results apply to the particular type of GMHT winter oilseed rape crop and herbicide management tested.

The research has been conducted by an independent consortium of research institutes and the work has been overseen by an independent Scientific Steering Committee. Today this committee has advised Ministers that the results of the final phase of the Farm Scale Evaluations has been successfully completed and have outlined the latest findings. The Chairman of the Scientific Steering Committee, Professor Chris Pollock, said: " I'm delighted that today marks the successful completion of a truly original and innovative study on farmland ecology. The information presented in this paper and the ones that preceded it show in unparalleled detail the processes that go on in the crop that sustain the natural food chains within the countryside. This study is much more than a research project on weed control in GM herbicide-tolerant crops. It will serve as a benchmark for all studies on the balance between agricultural production and the management of biodiversity in the countryside"

The Scientific Steering Committee and research consortium have produced an updated accessible summary of the research findings, copies of which are available free from the farm scale evaluation website.

The Scientific Steering Committee will now pass the results of the study to the Government's statutory advisers on GM crops - the Advisory Committee on Releases to the Environment (ACRE) - who will review the findings and advise the government on their conclusions.
 

BACKGROUND

For full details of how to obtain a copy of the results or the non-specialist summary see www.defra.gov.uk/environment/gm/fse

The field trials began in 1999 when the government asked an independent consortium of researchers to investigate how growing herbicide-tolerant GM crops might affect farmland wildlife compared with growing non-GM varieties of the same crops. Four GM crops were tested, all of which had been genetically modified to make them resistant to certain herbicides.

The results for three crops, spring-sown oilseed rape, beet and maize were published in October 2003. The research team found that there were differences in the abundance of wildlife between GMHT crop fields and conventional crop fields. Growing conventional beet and spring-sown oilseed rape was better for many groups of wildlife than growing GMHT beet and spring-sown rape. Some insect groups, such as bees (in beet crops) and butterflies (in beet and spring rape), were recorded more frequently in and around the conventional crops because there were more weeds to provide food and cover. There were also more weed seeds in conventional beet and spring-sown rape crops than in their GM counterparts. Such seeds are important in the diets of some animals, particularly some birds. However some groups of soil insects were found in greater numbers in GMHT beet and spring-sown rape crops.

In contrast, growing GMHT maize was better for many groups of wildlife than conventional maize. There were more weeds in and around the GMHT maize crops, more butterflies and bees around at certain times of the year, and more weed seeds.

Results for a fourth crop in the farm scale evaluations, winter oilseed rape, are now available. The research team found that there were also differences in the abundance of wildlife between GMHT winter oilseed rape fields and conventional oilseed rape fields.

Release from The Royal Society

Final GM Farm Scale Evaluations paper published today

The herbicide management of genetically-modified herbicide-tolerant (GMHT) winter-sown oilseed rape results in differences in the types of weeds present, compared to growing conventional varieties, according to a paper published today (Monday 21 March 2005) in the Proceedings of the Royal Society B: Biological Sciences*.

Sixty-five fields were sown with winter oilseed rape. Each field was split, one half being sown with a conventional variety managed according to the farmer’s normal commercial practice for weed control, the other half being sown with a GMHT variety, with weeds controlled by a broad-spectrum herbicide called glufosinate-ammonium. Comparisons in biodiversity were made by looking at the levels of weeds and invertebrates, such as beetles, butterflies and bees.

Effects on weeds
At harvest time, in the GMHT crop, both the amount of broad-leaved flowering weeds and the number of their seeds, which provide food for wildlife, were one-third of those in the conventional. But in the GMHT crops there were three times as many grass weeds and five times as many of their seeds as in the conventional. These effects were observed in the year of cropping and persisted in the following two years that data were collected. For the total amounts of weeds found, there was little difference between GMHT and conventional cropping.

Effect on invertebrates
For the majority of invertebrate species there was no significant difference between the GMHT and conventional herbicide regimes. However, by the July sampling, there were half the number of bees and two-thirds the number of butterflies found foraging in the GMHT crop areas, compared to the conventional. Also, consistent with previous Farm Scale Evaluation (FSE) results reported for spring-sown crops, the yearly totals for springtails, a type of detritivore which feeds on dead and decaying weeds, were higher in the GMHT crop areas.

Dr David Bohan, one of the authors of the paper, said: “These results present a number of interesting similarities with, but important differences to, the results for the spring-sown crops in the FSEs published in 2003. In terms of broad-leaved flowering weeds, the effects were broadly similar in winter-sown oilseed rape to those seen previously in spring-sown oilseed rape, with smaller numbers found in the GMHT crop area. But with grass weeds there was a significant difference, with many more present in the winter-sown GMHT crop. This resulted from relatively poor control of the grass weeds by late-applied glufosinate-ammonium to the GMHT crops compared with herbicides applied much earlier in the conventional.”

Dr Bohan continued: “Surprisingly, given the link between numbers of weeds and numbers of invertebrates seen in the spring-sown crops, most species were unaffected by the changes in amounts of broad-leaved and grass weeds in the winter-sown crop.”

Dr Bohan summarised: “The study demonstrates the importance of the effects of herbicide management on wildlife in fields and adjacent areas.”

The paper can be viewed online, free-of-charge, at: www.pubs.royalsoc.ac.uk/proc_bio_content/pdf/rspb20043049.pdf

Electronic appendix:  
www.pubs.royalsoc.ac.uk/proc_bio_content/pdf/rspb20043049supp.pdf

*Effects on weed and invertebrate abundance and diversity of herbicide management in genetically modified herbicide-tolerant winter-sown oilseed rape
by DA Bohan, CWH Boffey, DR Brooks, SJ Clark, AM Dewar, LG Firbank, AJ Haughton, C Hawes, MS Heard, MJ May, JL Osborne, JN Perry, P Rothery, DB Roy, RJ Scott, GR Squire, IP Woiwod and GT Champion.

Release from the Agricultural Biotechnology Council

abc statement on the results of the Winter Farm Scale Evaluations

abc welcomes today’s publication by the Royal Society of the final set of results from the Farm Scale Evaluation programme of GM field trials.

abc Deputy Chairman Tony Combes said “GM crops offer a better, more flexible weed management option for farmers and, as the results today indicate, the difference between the impact of growing GM and non-GM crops on biodiversity is minimal.”

Overall weed biomass was equivalent in both crops - grass weeds increased in GM crops while broad-leafed weeds decreased in GM crops.

Where there were observable differences with a few specific insects these were predominantly in July - a time in the crop lifecycle usually bereft of insects.  It is worth noting that a few insect groups were present in increased numbers throughout the trials.

Mr Combes continued: “These results confirm once again that GM crops give farmers the flexibility that they need to balance economic viability with environmental responsibility.

“This weed management option is delicate and precise enough to allow active management for weed and insect species. As with all weed management systems, some weed and insect species were positively, some negatively and others not at all.

“Coming so soon after the recently-published research from the BRIGHT Project and Broom’s Barn, today’s announcement shows once again that GM agriculture can be used in a positive manner, with the potential to provide marked environmental benefits.

“GM crops are now being grown by 8 million farmers, on 200 million acres in 17 different countries around the world. 2005 will see the billionth acre planted in the world since the introduction of GM crops 10 years ago. The UK has been field testing GM crops for 14 years and abc looks forward to the day when farmers in the UK are given the opportunity to access this important technology.”

BACKGROUND

What were the FSEs?

The Farm Scale Evaluations (FSEs) were an investigation by independent researchers aimed at studying the effect, if any, that the management practices associated with genetically modified herbicide tolerant crops might have on farmland wildlife, when compared with weed control used with non-GM crops.

They were the largest ecological study of their kind ever undertaken, in which insects, other small animals and weeds were measured in side-by-side GM/non-GM plots at 270 sites in the UK (including around 70 sites for winter oilseed rape).

The UK Government commissioned four FSEs on different crops in 1999; these were winter oilseed rape, spring oilseed rape, sugarbeet and maize. This final set of results refers to the trial of winter oilseed rape. All the others were announced in October 2003. Our response to the first results is available on our website at: http://ww.abcinformation.org/incubator/applications/press_releases/uploads/GM%20Nation%20Statement%20FINAL.doc  

Background on Winter Oilseed Rape (OSR)

Winter OSR is an important crop for farmers
It is grown in approximately 450 thousand hectares a year in the UK
The harvested seed is crushed for vegetable oil and the remaining meal is used for animal feed
Winter OSR is a far more profitable crop for farmers than its spring counter part

Are these crops safe?

Yes. Long before these trials were proposed the GM crop had to demonstrate it was at least as safe as the non-GM variety to regulatory authorities in the UK and around the world where these crops are grown commercially, including Canada and the US.

The herbicides used on the crops have also been tested as safe and are the same as the ones you can buy from the high street to use in your garden.

How did the GM and non-GM crops coexist?

In all the FSE sites and many other trials around the world there has been no coexistence problems. GM and non-GM winter oilseed rape crops were planted a minimum of 50m apart in line with SCIMAC guidelines.

What support did the agricultural biotechnology invite provide for the trials?

abc member companies are the licence holders for the crops (no crops can be grown in the UK without a licence) and provided the seed, herbicide and organised for the disposal of the crops. BayerCropscience is the licence holder for winter oilseed rape.

What happens next?

The Government has announced they will refer the results to the Advisory Committee on Releases to the Environment for advice on their implications. (House of Commons written answer 219527, 3 March 2005.)

Where can I find the report?

The full scientific results will be published in the journal “The Proceedings of the Royal Society” on 21 March 2005 and will be available on the journal's website at www.pubs.royalsoc.ac.uk.

The Scientific Steering Committee, which oversaw the evaluations, will publish a summary on the same day which will be available on the Defra website at: http://www.defra.gov.uk/environment/gm/fse/index.htm.