Grassland trials score big on weight gain and nitrogen reduction

IMPROVED animal performance and a potential 90pc reduction in emissions of a potent greenhouse gas could be delivered by new grassland species being trialled by Irish researchers.

Since 2013, researchers on the Government-funded SmartGrass project have been investigating the potential of multi-species grasslands in comparison to perennial ryegrass swards. Findings to date include: Estimated emissions of the potent greenhouse gas nitrous oxide (NO) per tonne of herbage from the multi-species swards was only 10pc of that from the perennial ryegrass swards. This was due to a combination of the lower levels of N fertiliser used and the high dry matter yields achieved from the multi-species swards. ÷Lambs reared on more diverse, lower input swards grew significantly faster, had lower intestinal worm burden, were slaughtered earlier and had a higher kill-out percentage than those reared on higher nitrogen input perennial ryegrass.

“Given the positive scenario these findings present for both farmers and the environment, UCD are currently establishing a long-term grasslands experiment with hydrologically isolated paddocks at UCD Lyons Farm,” says SmartGrass researcher Dr Helen Sheridan from the School of Agricul- ture and Food Science, UCD. “This national facility will be used to assess the sustainability of Irish grass-based agricultural systems through investigation of the interactions between three different pasture types, animal production, the environment, labour and farm economics.”

Funded by the Department of Agriculture, Food and the Marine, the SmartGrass project involves researchers from UCD, Teagasc and Belfast-based AFBI (Agri-Food & Biosciences Institute).

Experimental plots are located at UCD Lyons Farm and the Teagasc Animal and Grassland Research and Innovation Centre, Grange.