High-input dairy farms are not sustainable, either economically or environmentally.

This was the message from John Roche, scientific adviser to New Zealand’s agriculture ministry, who was speaking at the Positive Farmers Conference in Cork on Wednesday.

“Greenhouse gas emissions per hectare are higher in high-input systems.

Bringing in more feed to your farm increases your carbon footprint. That’s the law of physics

"The energy used in growing, harvesting and then feeding out crops is much higher than it is for grass-based systems.

“Anything that uses diesel is bad for the environment, it costs you money and reduces profit.

"Bringing in more feed to your farm increases your carbon footprint. That’s the law of physics,” he told farmers at the conference.

“Intensification will also increase ammonia emissions. Ireland is already exceeding its ammonia emissions and more intensive dairy systems will actually make this worse,” Roche said.

He said that it’s likely that some form of environmental quotas will be introduced in the future.

Speaking from the floor, Teagasc director Gerry Boyle said that there is no magic formula for tackling climate change, but there are a number of small things that every farmers can do.

“We can make quick gains by moving away from CAN-based fertilisers towards stable urea.

"The other area we can make progress in is regarding slurry spreading, by using more trailing-shoe and injector-type spreaders. There is likely to be a regulatory package around this in the future,” Boyle said.