Madam, - At its recent conference, the Irish Organic Network (ION) made its usual hare-brained plea for a wholly organic Irish agriculture (The Irish Times, May 21st).
This might work if we had a stable, fully-enclosed system (no exports, no imports) with recycling of all plant, animal and human wastes and remains. But Ireland exports about 80 per cent of its agricultural output. Such produce contains significant quantities of the major essential plant nutrients nitrogen, phosphorus and potassium (NPK).
Although nitrogen losses can be replaced using N-fixing plants (e.g. clovers), Ireland has negligible phosphorus and potassium sources to replace what is exported in food. In the absence of P and K mineral fertilisers (nasty "chemical", "synthetic" and "artificial" fertilisers, in ION parlance) yields would gradually decline to 19th-century levels, with serious job and export losses in our principal industry.
A foretaste of the above scenario was provided by the wartime shortages of phosphatic fertilisers in Ireland in the 1940s. There was widespread incidence of phosphorus deficiency diseases in crops and livestock, which was corrected only when P fertiliser imports resumed in the 1950s. - Yours, etc.,
CON O'ROURKE,
Park Lane,
Sandymount,
Dublin 4.