Fertiliser restrictions ‘can be beneficial’

‘Good for business and environment’

Fertiliser manufacturers say it still pays to apply urea – despite rules which mean it must be specially treated to reduce ammonia emissions.

Restrictions which came into force last year mean urea spread after 1 April must be treated with a urease inhibitor. Audited through the Red Tractor farm assurance scheme, the government rules aim to reduce greenhouse gas emissions from agriculture by restricting the application of untreated urea fertiliser.

Although some farmers may see this as a needless restriction, suppliers say the benefits could offset the burden of compliance.

Protected urea costs about 10% more than unprotected urea – but it can reduce ammonia losses by as much as 70%. This represents a 2:1 return on investment on arable crops at today’s prices, says Tom Wells, agronomist at Origin Soil Nutrition.

Multiple trials have shown protected urea offers equivalent yields to ammonium nitrate. It also has a lower cost per unit of nitrogen, so users can spread the same amount of nitrogen with fewer bags and refills.

There are other benefits too. Using protected urea means more of the fertiliser remains available to plant, rather than being lost to the environment – so it offers a viable option for several reasons, explains Mr Wells.

“Protected urea consistently matches ammonium nitrate’s yield responses and has the potential to be cheaper per unit cost of nitrogen due to a higher nitrogen content in each bag,” he adds.

Enforcement

Defra is monitoring the update of urease inhibitors. Failure to abide by the rules could see new legislation passed making it mandatory to include an inhibitor in all applications – not just those from 1 April each year.

“As an industry, we should be fully supporting this stewardship guidance to prevent regulation being enforced,” says ProCam business manager Phil Burrell.

“Not only should we be thinking of inhibitor use for stewardship, there is also the financial aspect. With fertiliser making up a large proportion of on-farm variable costs, anything we can do to enhance performance and get the most from that investment should be taken.”

Liquid fertiliser manufacturer Omex Agriculture, which supplies NitroShield, says trials carried out by the company’s research and development team ensures that the right amount of product is used according to the conditions at time of use.

Inclusion of NitroShield with the Omex liquid fertiliser range will reduce ammonia emissions, improve nitrogen use efficiency and consequently improve yield or provide the option of applying less nitrogen, says Omex technical director David Booty.

Reduction

“Our trials show ammonia emissions from Nitroflo alone are less than a third of that from urea – and similar to emissions from protected urea,” says Mr Booty. “NitroShield produces an average emissions reduction of 70% compared with Nitroflo without the inhibitor.

Applying fertiliser is more accurate through a sprayer, says Mr Booty. There is no waste outside the cropped area, no yield loss on field margins from the liquid – and the environmental benefits from less leaching.

Be clear on crop before spraying

Growers with late-sown cereals should be mindful of drilling date rules when spraying crops this spring.

The drilling date is important because it determines whether a cereal crop is defined as a winter crop or a spring crop – and which pesticides and growth regulators can be legally applied on those fields.

Any cereal drilled after 31 January is legally classed as a spring cereal – even if it is a winter variety. Similarly, a spring variety sown before the end of January will technically be considered as a winter crop.

“When winter cereals are sown after the end of January, they can only be treated with products approved in spring cereals,” explains Hutchinsons technical support manager Duncan Connabeer.

Any product authorised for use on winter cereals can legally be used on spring cereals sown before the end of January. But such use may not necessarily be supported by product manufacturers or agronomists.

Crop damage can occur when using some chemistry on winter cereals drilled in the spring – or spring cereals sown in the autumn. Growers should check labels carefully and discuss suitable options with their agronomist.