GM crops – in a field near yo u

Farm-scale trials on genetically modified herbicide tolerant (GMHT) crops are here—for the moment. They are taking place at the point where science, commerce and public opinion meet. This article looks at the planning and intention behind some of the trials, and what society hopes to learn from them.

Planned trials
A number of GM farm-scale trials are now being carried out across the country. Recent direct action by environmentalists to destroy these experiments has pushed the issue to the top of the political agenda. The table below indicates the location of the trials and the crops being grown.      There are two principal government-backed research projects.
    The Ministry of Agriculture, Fisheries and Food (MAFF) is funding the BRIGHT (Botanical and Rotational Implications of Genetically Modified Herbicide Tolerance) project involving five research centres (the National Institute of Agricultural Botany, Institute of Arable Crops Research, Morley Research Centre, and Scottish Agricultural Colleges) and will cost £600,000 over four years(1).
    The experiment will compare the agronomics and some of the environmental effects of a rotation with herbicide tolerant (HT) crops. Five sites are looking at two different HT rotations with one control rotation. Oilseed rape, sugar beet and maize are being grown, and the crops included in the rotations are tolerant to the herbicides imazamox, glyphosate, and glufosinate-ammonium.
    The project will also look at ‘worst practice’ assumptions as well as best practice. Sequential cropping of HT crops will be followed by crops that may be resistant to the same herbicide, in spite of the general advice not to do this. The aim is to produce an advisory package: “to guide farmers on the effective management of GMHT crops over the whole rotation to enable them to maximise the benefits and reduce any risks to a manageable level.”(2) Farmers are involved in the management of the project, and there is a commitment to publish interim research and results.
    At the same time, the  Department of the Environment, Transport and the Regions (DETR) is funding research(3) on farmscale evaluations of the impact of the management of GMHT crops (oilseed rape and fodder maize) which will run for four years on 20-25 farm sites throughout the country and cost about £3.3 million. The work will be led by the Institute of Terrestrial Ecology, working with the Institute of Arable Crop Research and the Scottish Crop Research Institute. The intention is to compare at each farm site two pairs of crops per year for three years, one crop GMHT and the other conventional.
    The economics and the yields of the relevant fields will not be studied. Effort will be concentrated on sampling plants and invertebrates to test the idea that there will be no difference in the diversity and abundance of wildlife associated with differences in management of the two crops. Birds and mammals will not be reported on, on the basis that most biodiversity is represented in insect species, which are the most responsive to impacts and change.
    According to Friends of the Earth (FoE), the trials have not been designed to prevent pollen from escaping from the crop, or to study pollen movement. FoE think it highly likely that cross-pollination of nearby crops or wild plants will occur. Any beekeepers in close proximity may also find their honey contaminated with GM pollen.

Trial sizes – creeping escalation
Current field sizes for the DETR trials are expected to be about 10 ha. AgrEvo has hopes, according to GeneWatch, that trials may be increased to 50ha for both winter and spring oilseed rape, and the field sizes may be increased to 50 ha for both. This would raise the possibility of  5,000 ha of GMHT oilseed rape being grown from 2000 onwards. Sue Mayer from GeneWatch says: “This hardly represents a controlled experiment. It shows that industry, not scientists, are calling the tune.”

GM success – straws in the wind
The benefits of GMHT crops are touted as reducing the use of herbicides, and increasing productivity. Whether the laboratory results can be achieved in the field is another question.  The US Department of Agriculture recently released an assessment of GM crops grown commercially in 1997 and 1998, which concluded that in two-thirds of the regions studied, yields of GM crops were no better than conventional yields, and in almost half of the study sites, pesticide use was identical(4).
    AgrEvo work on GMHT maize, oilseed rape and sugarbeet has confirmed that selective weedkillers will still be needed to cope with resistant volunteer weeds, and specific weeds that even some of the broad spectrum herbicides find hard to kill. AgrEvo produced glufosinate, used in the Liberty-link seed package for oilseed rape and maize. Both field pansy and nettles are not well controlled by the herbicide(5).
    A Spanish farmer reported disenchantment with Novartis GM maize, which has been grown for two years commercially in Spain—claiming the seed price increased 8% last year and 15% this year, and the grain held more moisture at harvest, leading to processor penalties(6).

Impacts on biodiversity
The Ministry of Agriculture Fisheries and Food (MAFF) carried out a review of the likely impact of herbicide use on GMHT crops. Although it came to no conclusion, it noted importantly that the current status of biodiversity in arable crops was poorly understood(7).
    BRIGHT and the DETR projects are welcome steps on the way to examining the wider impacts of GMHT crops on agriculture and the environment, together with the announcement that the Advisory Committee on Releases to the Environment (ACRE) is now empowered to set up a Wider Biodiversity Issues subgroup, and the coming into being of the Agriculture and Environment Biotechnology Commission (AEBC). 
    The timeframe of the experiments is not sufficient to indicate the impacts on biodiversity—only one hundredth of the seedbank will germinate in any one year. It can therefore take decades to evaluate with any certainty the impact of crops and management practices on native species.
    And observance of the Supply Chain Initiative on Modified Agricultural Crops (SCIMAC) guidelines will be no guarantee. The government’s statutory conservation adviser English Nature warned that farmers could follow the SCIMAC code but still ‘eliminate all wildlife from their fields.’
    The total budget for BRIGHT and the DETR work is around £4 million over the next 3-4 years. The R&D budget for organic farming is £2.1 million per year. How much of R&D budgets across MAFF and DETR are now being swallowed by GM issues, and how much should industry, which will be the large beneficiary of success, put into the pot?

Environmental impact
Commenting on the farm-scale trials, the Environment Minister Michael Meacher said: “The evaluations, which will take four years, will ensure that the managed development of the introduction of genetically modified crops announced in October 1998 will take place safely.”
    Others are not so convinced. According to Adrian Bebb of Friends of the Earth: “The trials are a farce. They will produce little or no scientific evidence of the environmental effects of GM crops. Only if there is a moratorium on commercial growing will there be time for a proper public debate on the future of farming in the countryside.”
    The position of Mark Avery of the Royal Society for the Protection of Birds (RSPB) is clear: “We oppose the commercial growing of GM crops until and unless they pass stringent tests.”

Comment
British farmland biodiversity has been in catastrophic decline over the decades in which synthetic pesticide use has been widespread. But the farmland ecosystem is so highly complex that the only scientific certainty that it has been possible to establish has been from a long-term monitoring study by the Game Conservancy which began in 1968, and more recent work by RSPB, that food sources of farmland birds have been depleted by pesticides. It is highly questionable that a four-year selective GM survey programme will detect all the changes that could, in the long term, bring about further losses in biodiversity, and even extinctions of vulnerable species, without proven yield or economic benefit.  (PB)

References
1. Managing herbicide tolerant crops in practice, BRIGHT Project Press Release, 14 October 1998.
2. Ibid.
3. Farmscale evaluations of the impact of the management of GM herbicide tolerant oil seed rape and maize on farmland wildlife, DETR, May 1999.
4. Field of Dreams, New Scientist, 10 July 1999.
5. Resistant crops will still need weed-killer, Farmers Weekly, 9 July 1999.
6. GM has young sceptics, Farmers Weekly, 25 July 1999.
7. Scientific Review of the Impact of Herbicide Use on Genetically Modified Crops, MAFF/PSD, December 1998.

[This article first appeared in Pesticides News No.45, September 2000, page 4]