With difficult growing conditions last season many crops were unlikely to have used all the nitrogen fertiliser applied, so soil reserves were generally higher than you might expect at the end of August.

But how much of that residual will still be available come spring 2013?

Allison Grundy, arable agronomist at GrowHow UK has been looking at rainfall data.

She said: “We’ve had an awful lot of rain since then. Looking at the figures up until the middle of December, rainfall across England and Wales has been on average 150 per cent of the norm, with some regions having over 180 per cent more rain than is usual over this period. Even the ‘driest’ region, the East has had 125 per cent of its usual rainfall and in the run-up to Christmas we saw even more rain.

“Leaching is bound to have been a problem on lighter soils, but where soils have been water logged denitrification is likely to be the main problem. On all soil types the cold and wet will have meant very little mineralisation – every which way you look, nitrogen is being lost.”

So will nitrogen levels be low next spring? Probably, but as GrowHow’s experience from its NMin nitrogen testing service over the past 15 years clearly demonstrates, N levels can be surprisingly variable, not only between years, but also between soil types, regions and even individual fields within the same year. Therefore oil sampling with GrowHow N-Min, to measure the amount of nitrogen a crop will get from the soil over the entire growing season, will be important in 2013.

One of the key conclusions from the independent HGCA Soil Nitrogen Supply research project, which reported in 2012, was that soil mineral nitrogen on its own is a relatively poor indicator of the amount of nitrogen that will come from the soil.

However, using the GrowHow NMin service which measures both SMN and AAN (Additional Available Nitrogen) shows a considerable improvement in accuracy.

“However, this does not mean that every field needs to be sampled,” Allison added. “Use NMin on barometer fields to check base levels but target fields that are likely to have low or high SNS as these will benefit the most from using N-Min,” she advised.

“Based on current values of nitrogen and cereals, we have calculated that using N-Min can give a benefit of between £100/ha and £200/ha, so it definitely pays.”