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 draw- back 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 conventio- nal 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 Mader 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. …