Back to nature - again

Since my attitude to organic farming is rather simplistic (I support it by instinct but have no detailed knowledge) I was interested to read the article by Louise Fresco and colleagues to see what three distinguished scientists had to say on the matter (Opinion, June 3).

I know little about the science, so all I could do was examine the quality of the arguments. I was very disappointed. The authors assert that organic farming has had a "more negative impact on the environment than its science-driven counterpart" but fail to explain why this might be so. They touch on biodiversity with the strange statement that while organic farmland has greater biodiversity than high-production land, the number of species does not come near that in rainforest. This seems to be comparable to me declaring that since I will never be as fit as Sir Steven Redgrave I should give up any idea of taking exercise. The underlying suggestion that as long as we have some pockets of biodiversity somewhere we'll be OK is deeply worrying.

Having given organic agriculture a good kicking, what is the answer offered by our scientists? Cut back the amount of chemicals and promote land use that allows natural enemies of pests to thrive. Where have I heard that before?

Chris Rust
Sheffield