Government seeks to reduce emissions from urea fertilisers

The government has launched a consultation today seeking views on reducing ammonia emissions from solid urea fertilisers used for growing plants and crops.

Ammonia emissions are harmful to natural habitats and our rivers and lakes, as well as to human health, with 87% of the UK’s ammonia emissions coming from farming. The Government has committed to reducing ammonia emissions by 8% of 2005 levels by 2020, and a 16% reduction by 2030.

Taking action on solid urea fertilisers has the potential to reduce pollution caused by:

• Ammonia reacting with other pollutants – nitrogen oxides and sulphur dioxide – to form particulate matter (PM2.5) which is harmful to cardiovascular and respiratory health.
• Nitrogen deposited on sensitive habitats such as peat bogs. This leads to excess nitrogen in soils that damages the growth of certain plant species.
• Nitrogen leaching through the soil and surface run-off which pollutes water courses, causing harm to plants and animals and impacting on water quality.

The consultation presents three cost effective options:

• A total ban on solid urea fertilisers
• A requirement to stabilise solid urea fertilisers with the addition of a urease inhibitor - a chemical that helps slow the conversion of urea to ammonium
• A requirement to restrict the spreading of solid urea fertilisers so they can only be used from 15 January to 31 March While each of these options will support the Government’s commitment to reducing ammonia emissions, a ban on solid urea fertilisers would achieve around 31% of the ammonia reduction target by 2030.

Reducing ammonia emissions will significantly reduce nitrogen deposition to land and in turn help reduce damage to peat bogs, which are an important carbon sink, thereby helping to tackle climate change.

Up to half of the fertiliser evaporates, causing ammonia emissions that react with other pollutants to produce fine particles whose microscopic size allows them to penetrate the lungs and enter the bloodstream, making them the most dangerous form of air pollution.

Public Health England attributed the serious smog episode in London in April 2014 partly to agricultural ammonia emissions.

The fertiliser also causes excess nitrogen in soil which promotes growth of brambles, nettles and hogweed that then crowd out wild flowers like harebell and bird's-foot trefoil. Almost nine out of ten designated wildlife sites in England are damaged by excessive nitrogen.

Defra expects farmers to switch to using more ammonium nitrate fertiliser, which is dearer but causes less evaporation and which crops absorb more efficiently.

The ban is expected to cost farmers £132 million up to 2030 and result in an additional 388,000 tonnes of ammonium nitrate being required per year, according to Defra’s impact assessment.

Clear Air in London stated: 'Many more technical measures and lifestyle changes will be needed if we are to reduce ammonia emissions from cattle and agriculture generally which are a major cause of particle air pollution episodes in spring.'