Ozone is costing farmers millions


7 June 2000



Ozone is costing farmers millions


TRAFFIC pollution is seriously damaging key British crops and costing farmers millions of pounds, according to new research.

Winter oilseed rape yields fell up to 14% and winter wheat produced a 13% loss when exposed to ozone levels typically found in more than 90% of UK arable land by University of Newcastle researchers

This calculates at as much as 25 per tonne for oilseed rape seed, with a further loss of 9 per tonne for the oil content which fell by 5%.

For winter wheat the loss works out at between 100 and 146 per hectare, says the department of agricultural and environmental science team.

In 1998 more than 2m hectares of wheat and 500,000 hectares of oilseed rape were sown in Britain.

Dr John Ollerenshaw who carried out the research said the results were unexpected.

“We were rather surprised because ozone impact had mainly been felt in Mediterranean and big continental areas, rather than places like Britain.”

He attributed the higher than expected levels to the effects of climate change, as higher sunlight levels stimulate the production of ozone.

Ozone pollution is caused primarily by road traffic and power station emissions. Nitrogen oxide emissions react with oxygen to create ozone, which can disperse far beyond the source of pollution.

The Newcastle teams field trials revealed that despite an absence of visible damage plants were affected.

Numbers of flowering branches on oilseed rape decreased by 38%, and while the plants produced more and larger seeds per pod, seed yields fell 14% in the sensitive Eurol variety.

In winter wheat a reduction in grains per ear and increase in infertile florets brought down yields.

Parallel research in Spain, where strong sunlight leads to more ozone developing in the lower atmosphere, recorded yield losses of 39%.

National Farmers Union environmental advisor Michael Payne said that climate change was a complex issue which could benefit crops through increasing carbon dioxide levels, as well as causing problems such as ozone pollution.

He added: “Ozone damage is a significant factor which must not be brushed aside.”

Dr Ollerenshaw said that if current trends of global warming continued farmers could expect to find ozone damage to crops becoming a growing problem.

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