Situated on the banks of the Boyne in Dowth, Co. Meath, an agritech research farm is currently undergoing ambitious research, investigating methods of farming that strive towards producing carbon-neutral beef and lamb.

The farm, which has set about being carbon neutral by 2025, consists of 91ha of grass, trees and hedges and is a mixed sheep and beef farm.

The system in place on the farm consists of a flock of spring-lambing ewes and sees 13-month-old Angus and Hereford cattle bought in the spring time and brought to slaughter off grass in the autumn.

As part of the World Steak Challenge, which took place in Dublin last week, judges from the event were invited to the Devenish farm on a study tour to find out more about the farm’s ambition.

The project manager for research at the Devenish Lands at Dowth, Dr. Connie Grace, gave attendees on the tour an overview of the research currently underway at the farm.

The farm was taken over by Devenish in 2014 and the first steps taken as part of that journey involved soil improvement and soil correction.

Connie explained: “When the farm was bought it had been quite dilapidated. The average soil pH on the farm was 5.5 when the optimum should be 6.3 – 6.5.”

We implemented the Devenish soil improvement programme to improve the soil’s chemical, biological and physical properties and as a result of that, the soil pH is now at 6.5.

“This in turn allowed us to build on soil fertility and develop different sward types to start reducing the amount of fertiliser we use.”

Sequestering carbon

The farm also undertook a baseline survey in 2017, using Lidar technology to identify the amount of trees and hedgerows on the farm.

This procedure was undertaken in an effort to identify how much carbon was being sequestered in the farm’s trees and hedgerows, as well as to identify the level of carbon stocks in the farm’s soils.

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Continuing, the former University College Dublin (UCD) PhD student added: “We have taken a lot of approaches in recent years to build our soil’s carbon.”

Some of the measures undertaken on the farm include:

  • Planting trees;
  • Planting hedgerows;
  • Agro-forestry;
  • Growing multi-species swards.

“All of these help towards the goal of building carbon stocks on farms,” Connie outlined.

Grass sward improvement

Connie told attendees at the farm walk: “When we improved our soil condition, we then focused on improving our swards and started research into grazing practices that are more sustainable.

“We knew there were huge pressures coming on the amount of Nitrogen (N) fertiliser used and as a result of that, we adopted an experiment to put science behind our strategy.”

The decision was then made to look at comparing ryegrass monocultures typically found on Irish farms to multi-species swards.

The ongoing experiment compares:

  • A ryegrass mono-culture receiving 170kg N/ha/year;
  • Old permanent pasture receiving 135kg N/ha/year;
  • Two different multi-species swards receiving 70kg/N/ha/year.

All pastures were stocked in the same way with sheep and cattle co-grazing together.

The findings

While the trial is still only in its early years, Connie outlined that if the farm was stocked “at 2.5 livestock units/ha with dairy cows, we would be sequestering 56% of the emissions we produced”.

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Commenting on the grazing systems, she explained: “Last year, we found that multi species – despite receiving 60% less fertiliser – grew about 40% more herbage and animal performance was extremely accelerated when grazing multispecies compared to a ryegrass mono-culture.”

Lambs on multi-species swards were slaughtered 42 days earlier than lambs on rye grass, the study has found.

“Beef cattle on multi-species swards were slaughtered earlier and consistently grew at 20% higher growth rates throughout the grazing season, and were brought to beef earlier as a result,” Connie added.

“When fertiliser reduction coupled with animal-performance improvements are compared, we have reduced our greenhouse gas (GHG) emissions from the farm by about 30% after one year alone.

“And that does not take into account the accelerated soil sequestration going on beneath the multi-species swards compared to ryegrass only,” she outlined.

“Devenish is starting to pave the way for farmers to realise there are ways to farm very economically – while being highly productive – with less environmental impact. We package all this together in a programme called Agrinewal,” Connie concluded.