AFBI tackles ammonia emissions from livestock

Slurry application to grassland by trailing shoe reduces ammonia emissions by 57% compared with splashplate application.
Slurry application to grassland by trailing shoe reduces ammonia emissions by 57% compared with splashplate application.

The emission of ammonia gas from agricultural practices in Northern Ireland constitutes both an environmental threat to sensitive natural habitats and a loss of valuable nitrogen from slurry and fertiliser.

The emission of ammonia is currently one of the biggest challenges facing the dairy industry and methods of reduction will be a key feature at the AFBI dairy open day at AFBI Hillsborough on June 6, 2018.

The UK is required to meet ammonia emission reduction targets set by international legislation which is independent of the UK leaving the EU. Northern Ireland currently produces 12% of the UK’s food, but also 12% of the UK’s ammonia emissions. 93% of ammonia emissions in Northern Ireland are derived from agriculture, with the dairy and beef cattle sector producing 73% of these emissions.

DAERA has recently commissioned a major research programme with AFBI who will work with Rothamsted Research and the Centre for Ecology and Hydrology to address ammonia emissions from livestock to ensure the specific conditions and key characteristics of Northern Irish agricultural practices are appropriately represented and addressed when both modelling and ultimately reducing ammonia emissions.

Tasks within this large research programme include:

l Determining the most cost-effective on-farm solutions for Northern Irish agriculture to reduce its ammonia emissions.

l Validation of modelled atmospheric ammonia concentration through the establishment of a network of 25 ammonia monitoring stations.

l Establishing robust emission factors for key livestock practices such as dietary crude protein levels, housing systems and floor types.

Up to half of the total nitrogen in dairy manure may be lost as ammonia under current typical Northern Irish manure management practices where no ammonia mitigation strategies are implemented. This represents a financial loss for the farmer who has to replace this with imported nitrogen fertiliser. Ammonia is created when urine and faeces mix and AFBI have already identified some simple on-farm practices which can significantly reduce ammonia emissions.

These have been endorsed by the Sustainable Land Management expert working group and include:

l Maximising the length of the grazing season – ammonia emissions from grazing animals are lower than from housed animals where slurry has to make its way through the manure management chain (housing, storage, landspreading).

l More frequent scraping and washing down of animal house surfaces and hardstandings where slurry accumulates.

l Covering outdoor slurry stores/lagoons.

l Replacing traditional splashplate slurry spreading with low trajectory spreading methods such as dribble bar and trailing shoe.

l Landspreading manure earlier in the season when conditions are cool but dry and avoiding warm and windy conditions when the potential for ammonia loss is greatest.

l Applying stabilised urea fertiliser rather than traditional straight urea.

l Planting tree shelterbelts immediately downwind of animal houses to ‘capture’ ammonia on site.

l Reducing the crude protein in livestock diets to meet, but not exceed, requirement.

Researchers at the AFBI dairy open day ‘Dairy Innovation 2018 - Profiting from AFBI Research’ will be on hand to discuss ammonia mitigation among many other topics ranging from feed efficiency, grass utilisation and animal health in dairy systems. The event will provide farmers with the opportunity to learn how to adopt the latest innovations back on the home farm. This is an opportunity not to be missed, so plan to be in AFBI Hillsborough on the 6th June where tours will run between 10.30am and 2.30pm. For more information on the event visit www.afbini.gov.uk/events or T: 028 9025 5636

In the interests of biosecurity those attending are asked to wear clean clothing not previously worn while in direct contact with their own animals. Outdoor workboots should not be worn. Protective overalls and footwear will be provided.