Total farm greenhouse gas (GHG) emissions on the average dairy farm increased in 2020, largely due to an increase in the average herd size, a new report from Teagasc shows.
However, GHG emissions/ha on dairy farms remained relatively stable, as the average dairy farm area increased. The decline in cattle GHG emissions offset the increases in dairy farm emissions.
Teagasc has released its latest sustainability report covering the year 2020.
The report uses the Teagasc National Farm Survey to track the performance of dairy, cattle, sheep and tillage farms across Ireland in improving their economic, environmental and social sustainability.
Lead author of the report, Dr. Cathal Buckley of the Teagasc Rural Economy and Development Programme, noted: “There is a sustainability paradox when results are examined by farm system.
“Dairy farms have a higher level of economic and social sustainability compared to most other farm systems, but also have higher levels of environmental emissions.
“By contrast, drystock farms have lower levels of economic and social sustainability, but also have much lower levels of environmental emissions.
“Tillage farms lie in between dairy and drystock farms in terms of economic sustainability, but also have low levels of environmental emissions.”
In terms of the trend over recent years, Dr. Buckley said: “It is notable that ammonia emissions declined in 2020 relative to the preceding years across all farm systems.
“Data which tracks farm management decisions indicates a significant movement towards low emissions slurry spreading methods and this is helping to reduce ammonia emissions.”
Comparing farm performance for recent years, Trevor Donnellan, head of the Agricultural Economics and Farm Surveys Department in Teagasc, and co-author of the report noted: “Dairying continues to be the powerhouse when it comes to economic sustainability compared to other farm systems.
“Average dairy farm incomes far exceed drystock systems and are also ahead of tillage farm incomes.
“On the flip side, dairy farmers typically have a less favourable work-life balance, typically working longer hours than farmers in other systems.”
GHG emissions
Focusing on greenhouse gas emissions, the data indicates that dairy farmers “continue to improve their environmental efficiency, with lower levels of greenhouse gases generated per tonne of product produced”.
However, the report said that “these efficiencies are being overridden by a rising dairy cow population”.
“In spite of the improved emissions efficiency, total dairy farm emissions continue to increase although emissions/ha remained constant on the back of increased area farmed.”
The average dairy farm produced 510.7t of agricultural GHG emissions (in CO2 equivalent) in 2020.
At 73%, most dairy farm emissions were from milk-based output. A further 26.7% was allocated to beef production on these farms (this would include emissions from cull cows and calf sales and transfers).
The remaining emissions, less than 1%, were associated with sheep and arable production on dairy farms.
The average cattle farm produced 131.6t CO2 equivalent (CO2e) of agricultural GHG emissions in 2020.
Beef production was the principal source, generating 97.1% of these emissions.
Sheep production was responsible for approximately 2.6% of total emissions on Irish cattle farms, and a very small proportion (less than 0.04%) was derived from other enterprises on these farms.
In 2020, the average sheep farm produced approximately 126.8t CO2e of agricultural GHG emissions.
Just under half (49.1%) of these emissions were generated by the sheep enterprise, with over half (50.5%) generated by a cattle enterprise present on specialist sheep farms, with the remainder coming from other sources (minor arable enterprise).
The average tillage farm produced 139.1t CO2e of agricultural GHG emissions in 2020.
However, only 24.1% of GHG emissions were generated from crop production. Despite being specialised in crop production, 68% of tillage farm emissions were from cattle present on these farms, with a further 7.9% from sheep.