Latest estimates suggest that greenhouse gas (GHG) emissions could fall by as much as 8% on some non-dairy farms this year.
That is according to the latest Teagasc Outlook 2024 report which projects “a slight decline” in the region of 1% in GHG emissions on dairy farms compared to 2022 results.
But, overall GHG emissions are expected to decline this year across all farm systems – measured on a whole farm or per hectare basis.
Why is this likely to happen?
According to Dr Cathal Buckley, Teagasc Rural Economy and Development Programme, it is chiefly because there is likely to be an overall reduction in livestock numbers and reduced chemical Nitrogen (N) fertiliser use in 2023.
GHG emissions fell across dairy, cattle, sheep and tillage in 2022 and Dr Buckley expects this will continue this year.
It is a welcome trend against the backdrop of ongoing analysis by the Environmental Protection Agency (EPA) that shows agriculture is the largest contributor to Irish GHG emissions by sector, accounting for “38.4% of the national emissions total in 2022”.
Under the Climate Action Plan 2021, agriculture has been set a target to reduce emissions by 25% by 2030.
Farm level emissions Teagasc, outlined in its Outlook 2024 report, are estimated based on “activity data multiplied by an emission factor”.
The main sources of agricultural GHG emissions are:
- Methane (CH4) emissions from enteric fermentation (EF) by ruminant livestock;
- CH4 and nitrous oxide (N2O) emissions from manure management – including production and storage of livestock manures;
- N2O emissions resulting from the application of manures and chemical fertilisers to soils.
The latest GHG and ammonia (NH3) emissions projections from Teagasc for 2023 are based mainly on changes on farm activity levels.
According to the Teagasc the major factors that “can significantly influence emissions” are animal numbers and the type and quantity of chemical N fertiliser and lime applied to land.
Current figures suggest a fall in overall cattle numbers – with the exception of dairy cows and cattle aged two years and over – while the total number of sheep is likely to increase “very marginally”,
Meanwhile Teagasc detailed in theOutlook 2024 report that latest sales data for fertilisers suggests that common fertilisers purchased in volume terms – straight CAN and NPK compounds – have declined.
But the sales of protected urea fertiliser – associated with lower GHG emissions and lower ammonia emission – have remained stable.
Preliminary figures also suggest that the volume of lime applied decreased around 16% between 2022 and 2023 – which has implications for both GHG emissions as CO2 is released when lime is applied.
According to Dr Buckley one other key component which has and will continue to be fundamental to driving down GHG emissions on Irish farms is the “adoption” of certain technologies that can help reduce gaseous emissions at farm level.
Teagasc has found that there has been a significant “transition” by farmers to the use of low emissions slurry spreading (LESS) technology.
It has estimated that the quantity of slurry spread by LESS increased from 48% in 2021 to 59% in 2022 and it has “assumed this transition continues in 2023”.
Teagasc projections
Overall the latest projections suggest a “slight decline” in GHG and ammonia emissions on dairy farms in 2023 compared to 2022 however, there are also likely, according to Teagasc to be “increased emissions associated with increases in the dairy herd being offset by significant reductions in chemical N and lime usage”.
Teagasc also outlined in its Outlook 2024 report that more significant reductions in GHG and ammonia emissions” are projected for drystock and tillage farms “on the back of reduced livestock numbers and chemical N/lime applications as well as transition to the use of LESS”.