Recently proposed restrictions on using nitrogen fertiliser (News, 24 August), both manufactured and in manures and slurries, should affect pure arable farms less than mixed and livestock units.

But some of DEFRA’s Action Programme ideas for the extended NVZs, to reduce nitrate pollution of water and counter potential EU legal action, could affect operations and require more attention to on-farm practices and record-keeping, says ADAS principal scientist Peter Dampney.

Many farmers already take account of soil N supply when assessing the need for fertiliser, either directly by soil analysis or by

A:Typical NMAX Rates (Kg/Ha)
8t/ha feed wheat (med soil)	220
10t/ha feed wheat (shallow soil)	280
9t/ha milling wheat (med soil)	280
3.5t/ha oilseed rape	220*
Potatoes	270

considering soil type, cropping and manuring history, he acknowledges.

“Farmers doing that should really have no cause for concern. But we know from surveys many farms using organic manures don’t take account of their N values.”

That process would become mandatory under the proposals.

“Farmers may be initially alarmed by the apparently low limits on N use,” adds Mr Dampney. “But it’s important to remember these so-called Nmax rates are farm averages, not individual field limits.”

A new yield adjustment factor, absent from the current official RB209 recommendations book, would also gives growers flexibility, he believes. (See box A).

“There’s no mandatory field maximum, but farmers will have to allow for minimum values of manure N efficiency.” And the figures for that will tighten after 2012, he notes (see box B). “The differences are there to allow farmers time to prepare for the changes.”

The ban on spreading artificial fertilisers between 1 September and 31 January would remain, though there would be some specific exemptions, including oilseed rape, where up to 30kg/ha of N in the autumn would be permitted.

Organic manures with plenty of readily available N, such as poultry litter and pig slurry (but not farmyard manure), would have to be incorporated into bare soil or stubbles within 24 hours. “That’s another new requirement.”

And although the Nitrates Directive with which the EU is threatening the UK does not require it, DEFRA is keen to get reaction to its proposal that no land be left bare over-winter except that following crops harvested after 1 September.

“That might not mean having to sow cover crops,” says Mr Dampney. “Natural regeneration could be enough.

“When it comes to the record-keeping proposals, a lot of what is being asked for is already required under the current NVZ rules.” But some extra work is probably inevitable.

DEFRA & NFU opinion News, p12 How it affects livestock farmers, p37

MIXED REACTION from farmers

Mark Ireland, a former Nitrate Sensitive Area pilot, stresses that any NVZ extension must be scientifically justified. “I would be very much against DEFRA’s proposal to apply the Action Programme throughout the whole of England.” NFU vice- president Paul Temple questions whether any lessons have been learned from the original NVZ areas. “Remarkably little is known about cause and effect, and the proposals certainly haven’t been costed.” Both men are against compulsory over-winter cover crops, Mr Ireland’s NSA experience showing they are bad for long-term weed control. They have a cost whereas managed regeneration could provide sufficient cover, suggests Mr Temple. Neither welcomes the prospect of yet more record-keeping. “We’re getting to the stage where we have to write an assessment for everything we do on a daily basis – and for what benefit?” says Mr Ireland. Mr Temple wants commonsense to prevail. “Dispensations are key.” FW’s midlands Barometer farmer Ben Atkinson, however, is relatively relaxed. “I can’t say I find the proposals too horrific. We’re just within an NVZ anyway and have to work with RB209 which in effect puts the whole country under NVZ type restrictions – and RB209 is quite workable.”