THROWING nitrogen at wheat to achieve higher protein will have to change markedly as application rates come under increasing environmental scrutiny.

That’s the view of ProCam’s agronomist, Ian Jackson, who said that methods of supplying N fertiliser to support growth and protein content of arable crops will need to be finely tuned.

Talking ahead of the summer nitrogen top-up aimed at boosting grain protein, he said this should be a time where alternative methods can be tried.

With environmental restrictions on the total nitrogen dose that can be applied to crops over the season and pressures to cut ammonia emissions under the government’s Clean Air Strategy, Mr Jackson said alternatives to traditional granular or urea forms of nitrogen will become increasingly important.

This will especially be the case later in the season as it becomes warmer and drier, in order to cut down on volatilisation of ammonia and because granular nitrogen requires soil moisture for good plant uptake, he argued.

“As an alternative to both granular fertiliser and liquid urea, which is often used as a later-season alternative to granular nitrogen, experience on farms over recent years has shown that applying modified forms of nitrogen has given good results.

“Applied as foliar sprays, these treatments contain nitrogen in a form that plants can readily utilise – it doesn’t have to be metabolised. This means it can be applied to the plant at relatively low dose rates. Also, because it is absorbed by foliage rather than roots, it is less reliant on moisture for plant uptake.”

Both of these factors make these types of treatment an environmentally efficient way of applying later-season nitrogen, said Mr Jackson.