ngin - Norfolk Genetic Information Network

31 May 2002


The second item, by Steve Connor the science editor of the Independent, makes an interesting contrast with the first report from The New Scientist. Connor extensively quotes GM enthusiast and self-appointed expert on organic farming, Prof Anthony Trewavas FRS.

Interestingly, it was Connor who in the run up to the Lancet's publication of the Pusztai and Ewen paper ran a spoiler piece based on an attack by Prof John Pickett, the only reviewer of the paper arguing against publication. Connor's article appears to have been part of a concerted campaign to discredit the Pusztai paper prior to publication.

It is also worth noting that Connor has been a long time supporter of the SIRC, even serving on its highly partisan Forum that laid down guidelines for journalists and scientists on how they should report science stories in the media.

Trewavas, of course, needs little introduction!  See: 'Prof Trewavas requires a health warning: Reports on the media-war waged against organics by a scientist renowned for his extreme, unsupported and unfounded assertions.' Includes an article with detailed criticism of a Trewavas' opinion piece in Nature.

"Journalists who blindly quote 'experts' without illuminating their agenda are simply adding another layer of fog to an already confusing debate" - Howard Kurtz, Columbia Journalism Review March/April 1990

1. 20-year study backs organic farming
2. Prof Trewavas on new study


1. 20-year study backs organic farming

Fed Pearce, New Scientist
19:00 30 May 02
[Journal reference: Science (vol 296, p 1694)]

The world's longest running experiment in comparing organic and conventional farming side-by-side has pronounced chemical-free farming a success.

"We have shown that organic farming is efficient, saves energy, maintains biodiversity and keeps soils healthy for future generations," says Paul Mader of the Research Institute of Organic Agriculture in Frick, Switzerland, which carried out the 21-year study.

Although crop yields on organic plots in the experiment were on average 20 per cent lower than those on conventional plots, the ecological and efficiency gains more than made up for it, Mader says.

Soils nourished with manure were more fertile and produced more crops for a given input of nitrogen or other fertiliser. "The input of nutrients like nitrogen were as much as 50 per cent lower, so overall the organic system was more efficient," he told New Scientist.

Not all crops did equally well. Potato yields on organic plots were only 60 per cent of those on conventional plots. But organic winter wheat achieved 90 per cent, and grasses fed on manure did just as well as those fed on fertiliser.

Mader argues that the biggest bonus is the improved quality of the soil under organic cultivation, which should ensure good crops for decades to come.

Earthworms and fungi

Organic soils had up to three times as many earthworms, twice as many insects and 40 per cent more mycorrhizal fungi colonising plant roots. Soils microbes went into overdrive, transforming organic material into new plant biomass faster than microbes in conventional plots.

More predictably perhaps, organic plots contained up to 10 times as many weed species as conventional plots sprayed with herbicides.

"Under European conditions, we can clearly grow our food with much less chemical input than we do now," says Mader. "But of course a 20 per cent yield reduction in a country like India would have fatal consequences."

However, in practice, where poor farmers cannot afford expensive agrochemicals, switching to organic methods boost yields, he says: "Last year I visited a project in India, the Maikaal Project near Indore, where more than a thousand farmers are growing food organically - and increasing their yields compared to neighbouring conventional farmers."

Jules Pretty, director of the Centre for Environment and Society at the University of Essex, who recently completed a global study of organic farming, said the findings confirmed his conclusion that "organic farming is more efficient and in many circumstances can increase yields for farmers".


2. News analysis: Organic methods are viable, but benefits to environment remain hidden in the soil

Swiss team's 21-year research project provides scientific backing for naturally grown products although more evidence is needed

By Steve Connor, Science Editor
The Independent, 31 May 2002

Organic farming is good for the environment. That statement might appear to be a self-evident truth, but there has been little hard science to prove it until today and the publication of a study in the journal Science.

A team of Swiss agriculturists has just completed a 21-year comparison of organic farming, which uses no synthetic fertilisers or pesticides, and its conventional cousin, which relies heavily on agrochemicals. The team concluded that although organic farming produced significantly smaller yields than the conventional approach, the drawback was more than compensated for by the long-term benefits to the environment.

The findings are based on comparing yields with the amount of fertilisers and pesticides sprayed on five types of crop: potatoes, barley, winter wheat, beets and grass clover. Although the organic fields produced on average a 21 per cent lower yield, they needed between 34 and 51 per of the amount of minerals and other nutrients used on the conventionally farmed fields.

Paul Mader, of the Swiss Research Institute of Organic Agriculture in Frick, and the leader of the team, said the findings indicated that organic farms used their resources more efficiently and that, in the long term, the organic approach was a commercially viable alternative to conventional farming. "These results should be encouraging for farmers, because they can see that yields are stable over time and that soil fertility has increased," Dr Mader said.

The study showed organic farming produced more food with less energy and fewer resources a contradiction of many criticisms of the organic approach, which have emphasised its inefficiency and lack of productivity.

Proponents of organic farming, such as the Soil Association in Britain, frequently assume that it must be better for the environment. In reality, there have been few long-term studies to back up this claim.

The Swiss study, however, found that the organic soil in the experiments was richer, with a larger and more diverse range of beneficial organisms than the soil farmed conventionally. The organic soil harboured more microbes involved in nutrient recycling, more earthworms and more pest-eating spiders and beetles. Because the study ran over many years, the scientists were able to make a statistically valid comparison.

"Soil fertility and biodiversity develop slowly, and this is why a long-term study is essential," Dr MSder said. "There is a need to evaluate alternative farming systems as a whole system in a scientific way. The most appropriate method to do this is still to conduct long-term experiments, which can be analysed statistically and performed under identical soil and climate conditions."

Although many of the high-profile supporters of organic farming, such as the Prince of Wales and the broadcaster Jonathan Dimbleby, will no doubt find comfort in the Swiss study, some critics are not swayed by it.

Anthony Trewavas, professor of plant biochemistry at the University of Edinburgh, said the Swiss study was severely limited in what it demonstrated about organic farming conducted elsewhere in the world. Field size and climate in Britain were different from Switzerland, Professor Trewavas said. "Unfortunately, the data in the paper suggests that no extrapolation can be made to other soils, climates or countries. The yields of wheat [in the Swiss study] are low, well under half what would be achieved in the UK," he said.

Professor Trewavas has been one of the sternest critics of the organic farming lobby. Two years ago he wrote an article in the journal Nature that questioned the widespread assumption that organic farming was good for the environment. One of his main criticisms of the Swiss research was that it did not take into account a recent innovation in conventional farming where seeds are drilled directly into the ground, with minimal ploughing.

"Ploughing is the most dangerous thing you can do to the soil," Professor Trewavas said. "The plough disturbs ground-dwelling animals, it allows nutrients to be washed away in the rain and it encourages soil erosion."

A similar comparison of organic and conventional farming in Britain, named after a farm called Boarded Barns in Essex, had found that "no-till" conventional farming was better than the organic alternative, with, for example, double the number of earthworms in the soil, Professor Trewavas said. "Organic farmers have to plough to eliminate weeds and bury weed seeds. Weeds are the major problem with organic farming."

No-till conventional farming used one third of the fossil fuel energy of organic farming when calculated on a yield basis, he said. "Organic farming simply wastes energy by having to plough. Herbicide-resistant crops are the way forward here. A single treatment with innocuous herbicide, coupled with no-till conventional farming, avoids this damage and retains organic material in the soil surface."

Another assumption about organic farming is that it causes fewer nutrients to be washed into streams and rivers, reducing dame to wildlife. In fact, there is some evidence that applying manure, the preferred organic fertiliser, rather than chemicals rich in nitrates and phosphates can be just as polluting. Indeed, one study by the publicly funded Rothamsted research station in Hertfordshire found that nutrient run-off from manured fields was higher than from conventionally farmed fields, Professor Trewavas said. Another issue that had to be addressed was the damage to crops from pests. The Swiss study showed pests were a more serious problem for crops grown organically. Professor Trewavas said the study seemed to confirm the fear that organic farms could act as repositories of disease.

The arguments are far from over. What is clear from the Swiss study is that more comparisons are needed to assess the long-term effects and support the belief that organic invariably means "good for the environment".


3. UK: Blair wrong on science stance

22 May, Soil Association
[via Organic Trade services:]

In response to Tony Blair's proposed speech in support of science to be given last Thursday, Peter Melchett Policy Director of the Soil Association said:

"Tony Blair is wrong to imply that people are against GM food because they are anti-science, and is regurgitating chemical industry propaganda.

"The vast majority of the British public, environmentalists, organic farmers and businesses are pro-science - but this does not mean that we have to agree that Monsanto, Tony Blair and pro-GM scientists should run our lives and decide what we eat.

"The Prime Minister cannot argue that it is in Britain's economic interest to support GM food. Around 96% of GM crops are grown in just three countries - the USA, Canada and Argentina. The market is dominated by Monsanto, an American company which accounts for over 90% of all GM crops. Neither of the other major players, Syngenta and Bayer, are British. GM crops have been a disaster for American farmers and taxpayers.

"Farmers in the US have lost billions of dollars of exports, and US farm subsidies from the taxpayer have shot up.

"GM technology has given scientists almost limitless power over life - the public is right to insist that we make the choices about what is right and what is wrong. It is significant that GM food has been widely rejected across the globe.

"The BSE crisis highlighted that advice given by scientists and Government is not always correct or in the public's best interest. In the 1980s, the Soil Association banned the feeding of animal protein to cattle in response to growing concerns about the potential outcome. "

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