£13/t premium needed to justify milling wheat N rates

A premium of at least £13/t is needed if growers are to justify the higher nitrogen requirements of modern high yielding milling wheat varieties, according to a HGCA-funded project.

In the project, some 38% of modern high-yielding group one and two wheats (e.g. Einstein, Malacca, Xi19) needed more than 280kg/ha N to achieve 13% protein and 25% needed more than 300kg/ha N.

At the nitrogen rates needed to achieve 13% protein, the extra margin over nitrogen cost was around £100/ha (assuming all crops achieved a £13/t) premium. But, at lower premiums and success rates, the margin did not generally justify growing milling wheat compared to feed wheat, said ADAS’s Peter Dampney, who led the project.

“There was uncertainty about the nitrogen requirements of modern group one and two wheat varieties which are high yielding, but where a high grain protein may be needed,” he said.

Just one third of group one and two milling wheat crops met all the quality standards in last year’s HGCA cereal quality survey, so growers must pay more attention to nitrogen requirements this season.

“With fertiliser N prices increasing substantially in recent years, the breakeven ratio has likewise increased, reducing economic optimum N rates. This in turn has made it more difficult to achieve both high yields and required protein contents,” he added.

The project also found that foliar urea applied during milk development stage was generally more effective than solid ammonium nitrate at increasing protein. “Effects of late N on yield were uncommon and small,” Mr Dampney added.

The HGCA hopes the results of this project will be considered in the revision of DEFRA’s Fertiliser Recommendations (RB209). See final project report PR 400 at www.hgca.com for more.