Letter: `Efficient' farms

Sir: Professor Trewavas ("Is organic food safe?", 30 July) makes the common mistake of ignoring the real costs of agrochemical agriculture when he criticises organic farming.

The peculiar, but widely used, definition of "efficiency" ignores the value of organic matter and humus to long-term viability and production. It ignores the high costs of soil erosion from soils which have been depleted of organic matter by a reliance on artificial inputs and it ignores the heavy use of fossil energy in terms of pesticides, fertilisers and machinery to produce every grain.

This peculiar "efficiency" takes no account of the widespread contamination of ground and surface water by pesticides and nitrates and their knock- on effects on human health. It does not put a value on the loss of wildlife which cannot coexist in such a system.

But perhaps most strange of all is the implication that organic agriculture is less efficient because it employs more labour. Putting money into the pockets of a local workforce is of far greater benefit than providing revenue to distant and unaccountable agrochemical and fertiliser manufacturers.

If that is defined as inefficient, then it is the rules that we must change.

MARTIN HUGHES-JONES

Green Party Agriculture Working Group

Tiverton, Devon