‘It’s important to protect the sustainable image of our dairy farms’

A litre of milk produced in Ireland is the most efficient litre of milk produced in the European Union (EU). Irish dairy farmers produce the lowest greenhouse gas (GHG) emissions per litre of milk in the EU28. However, we are the third highest producer of GHG emissions per capita in the EU – 33% of these emissions come from agriculture.

How sustainable are Irish dairy farms? Teagasc’s James Humphreys answered this question at the recent Irish Fertilizer Association spring seminar.

Dairy production in Ireland is built on solid sustainable foundations and is proactive in meeting emerging societal requirements for environmental protection and animal welfare, Humphreys said.

More than ever, it is important to protect and foster the sustainable image of our dairy farms.

Humphreys stated that our high GHG emissions per capita are related to high livestock numbers and a relatively low human population density.

Ireland has the lowest nitrogen (N) surplus in the EU and the sixth highest level of water quality.

Phosphorus efficiency – highest in the world

Ireland has also improved its phosphorus (P) efficiency – moving from 40% in the 1990s to 70% in 2018. This is mostly due to the low levels of concentrate used and the high level of grazing systems.

Humphreys stated that Irish dairy farms have the highest P use efficiency in the world.

High P use efficiency is important for water quality; but also because global reserves of P are diminishing and P is an expensive fertiliser input.

Nitrogen use

He also stated that our weakness is our N use. Ireland’s grass-based system leads to the use of more N than other countries. Other high dairy output countries, like the Netherlands, rely on inputs like maize.

N use efficiency is lower under grazing systems. Urine patches in fields lead to the uneven application of N in concentrated patches, which can lead to leaching of N through the soil.


Grass is what makes our dairy production sustainable and helped to generate dairy farm incomes exceeding the average industrial way for the past 10 years – apart from 2009.

The low level of concentrates in Irish dairy diets results in less GHG emissions and less phosphorus pollution. Irish milk has one of the lowest carbon footprints in the world, which makes it very attractive as a food ingredient.