ALTHOUGH PROGRESS in T-sum has slowed as mild temperatures have been replaced with night frosts, some areas have already hit T-200 – the optimum timing for nitrogen applications.

The mildest areas along the south and south-west coasts of England have reached T-200, says Ian Barrie from the Met Office at ADAS Wolverhampton. “However, soil moisture conditions over most of the UK are still unsuitable for heavy traffic. The exception is East Anglia, where soil moisture deficits have built up to 10-20mm.”

Wet ground conditions mean it will be a while before producers in south-west England get out with their nitrogen applications – even where T-sum has been reached, says south-west Kemira GrowHow adviser Mike Shepherd.

“We’ve had a wet January, although it is drier and colder now, which should help. Most producers in this region don”t turn out until March, when T-sum is well past and they have enough silage, so there is no pressure to turn out early,” he says. “They know that once ground conditions improve this year, their fertiliser applications will be used efficiently. T-sum has more of an effect further north where producers could lose potential grass growth.”

However, producers following a New Zealand system will want to turn cows out in February, and for these Mr Shepherd reckons they will typically apply about 50kg/ha of nitrogen (40 units/acre) to keep grass ticking over.