Clean air strategy: How UK livestock farmers can reduce ammonia emissions
Earlier this year the Government launched an ambitious new strategy to clean up our air.
The measures set out in the Clean AirStrategy will help cut the costs of air pollution to society by £1.7 billion every year by 2020, rising to £5.3 billion every year from 2030.
The strategy includes commitments to support farmers’ efforts to tackle air pollution in England, particularly by reducing emissions of ammonia gas.
Around 87 per cent of the UK’s ammonia emissions are from agriculture. Most ammonia is emitted from livestock manures in animal housing and stores, and when organic manures and mineral fertilisers are applied to land.
Ammonia emissions have increased since 2013, mainly due to increased livestock numbers and more farmers using urea-based fertilisers.
Ammonia combines with other chemicals in the atmosphere to form fine particulate matter (PM2.5) which is harmful to human health. When deposited on land, ammonia leads to over-fertilisation of sensitive wildlife habitats leading to a loss of lichens, mosses and wild plant species.
Catchment Sensitive Farming has provided some guidance on what livestock farmers can do to reduce emissions.
David Ball, AHDB senior manager for environments and buildings, says: “Many of the options available make good financial sense, reducing ammonia emissions is all about retaining more of the valuable nitrogen within manures and slurries, which when applied using low emission techniques maximises crop production and reduces the need to buy in costly mineral fertilisers.”
Ways to reduce emissions
- Cover slurry tanks and lagoons. Some types of cover exclude rainfall and could give you substantial savings on slurry storage and spreading if you farm in a high-rainfall area. By law, covers will be required on slurry tanks and lagoons by 2027.
- Cover heaps of solid manure where safe to do so.
- Funding for covers is available to farmers in high priority water catchment areas through the Countryside Stewardship Scheme (England only).
- Work with a registered feed advisor to ensure crude protein levels are matched to the requirement of the animal, otherwise excess nutrients are wasted in manure and can cause pollution.
- Regularly scrape and wash floors and yards.
- Regularly empty slurry from pits to a covered store.
- For new sheds, specially designed flooring and scraper systems can be combined with V-shaped slurry pits to reduce the surface area of slurry exposed to air. Defra plan to introduce housing design standards in England and will work closely with industry to develop these.
- Consider innovative techniques such as pH reduction to reduce ammonia in-house, in-store and in-field. Defra have previously offered grants for this equipment and is currently undertaking a three-year research project looking at the potential of wider scale implementation of pH reduction.
Manure and slurry spreading
- Spread in cool, windless and humid conditions in accordance with a nutrient management plan.
- Rather than a splashplate, spread slurry using a trailing hose or dribble bar (30 per cent reduction in emissions), trailing shoe (60 per cent) or injector (70 per cent). It will be law to use one of these three types of kit for spreading slurry by 2025.
- Funding towards these ‘low emission spreaders’ will be available through the Countryside Productivity Small Grant Scheme (England only) later this year.
- Incorporate solid manure into soil as soon as possible.Defra are planning to require solid manure to be incorporated within 12 hours of spreading, unless you have a no-till system.
- Rather than using urea-based fertilisers, use urease-inhibited urea or an alternative like ammonium nitrate. On average in the UK, around 10 per cent of the nitrogen in urea-based fertilisers is lost as ammonia, compared to 2 per cent of the nitrogen in ammonium nitrate.
- Use a nutrient management plan, with tools like Manner NPK and AHDB’s RB209 Nutrient Management guide to work out which product to use, how much is needed and when to apply. Weather conditions are also important.
Farmers in Catchment Sensitive Farming areas are now able to access one-on-one advice on practical and cost-effective ammonia mitigation options, as well as support with grant applications.
To find your local contact visit www.gov.uk/catchment-sensitive-farming