The tighter rules to prevent possible groundwater pollution and environmental problems will probably come into force next year.

They will include a 170kg per hectare whole-farm annual limit for nitrogen fertiliser, longer closed periods when organic manures cannot be spread and more long-term slurry storage.

Arguing against these restrictions, backed by sound science, is "top of our immediate agenda", said Jim McLaren, the union's vice-president, this week.

He told journalists: "It's time-critical and finance-critical for thousands of farmers. No farm, or any business, can afford to have regulatory restrictions imposed in the absence of scientific evidence or proof that they will deliver a benefit."

Farmers and the union support any sensible efforts to protect water quality, he said: "But window-dressing measures to keep Brussels happy will only harm farming and do nothing for the environment."

There are four NVZs covering about 14 per cent of Scotland - part of Aberdeenshire, Moray, Banff and Buchan, part of Strathmore and Fife, part of Lothian and Borders and the whole of Lower Nithsdale.

Source: The Scotsman