Farmer uptake of the reduction measures laid out by Teagasc will be needed to take farming’s ammonia emissions in line with the targets set out under the national emissions ceiling directive and prevent agriculture from again missing its ammonia reduction target, a Teagasc researcher has said.
These measures - described in Teagasc’s ammonia marginal abatement cost curve (MACC) - include using low-emission slurry spreading (LESS) technologies to spread 90% of cattle slurry by 2030 and liming 15% of the country’s grasslands annually.
Ireland has not reached emissions reduction targets for seven of the 10 years between 2010 and 2019, with a continuation of this non-compliant trajectory for agriculture currently projected by the Environmental Protection Agency (EPA), Teagasc emissions researcher Dominika Krol has said.
“According to EPA projections, we will be non-compliant for the next 10 years, because we have reduction commitments even more stringent now than over 2010 to 2019,” stated Krol on a Teagasc Signpost webinar.
However, should farmers adopt the complement of mitigation measures in the numbers predicted by Teagasc in the MACC, agriculture’s compliance with the emissions directive could be reached as early as 2025, Krol explained.
“If we fully adopt measures from the ammonia MACC, we can actually get compliant around 2025 and still be compliant with ammonia regulations for the rest of the commitment period.
“So, this is really good that there is a pathway to compliance there,” she said.
Storing and managing slurry
Most of agriculture’s ammonia emissions come from the winter housing period and the subsequent handling of the organic manures produced while stock were in sheds, Krol told the webinar’s attendees.
Chemical fertiliser, on the other hand, accounts for only about 10% of the ammonia emissions from Irish agriculture.
“That short period when the animals are in the house – in the shed – and the resulting slurry storage, that is responsible for half of our ammonia,” she said.
A further 30% of emissions result from the agitation and spreading of slurry collected during the housing period, Krol went on to say.
Grazing is currently responsible for only 12% of the sector’s ammonia emissions, she explained, despite the grazing season making up a far higher proportion of the year when compared with housing.
A switch away from CAN to protected urea and LESS uptake at the numbers stipulated in the MACC could deliver 80% of the reduction needed to ensure compliance with the emissions target, according to the Teagasc researcher.
“What really stands out is the LESS - especially for bovines - and protected urea and those two alone can provide 80% of the ammonia mitigation needed to bring us closer to compliance,” said Krol.
Other practices, such as increasing the frequency of slat scraping, may also play a role in reducing ammonia emissions from agriculture.
“If they scrape the surface every three hours, they can save ammonia emissions by around 50%. If they are scrape every hour, they can reduce ammonia by nearly 80%. That is a huge reduction there,” she commented.