Utilising legumes and growing cover crops was a key focus of a recent Germinal Ireland technical briefing.
The event identified ways in which climate-smart agriculture can help grassland farmers lower inputs while continuing to drive production and improve soil health.
Mary McEvoy, Germinal technical director, told delegates: “Pasture utilised continues to be a key driver of profit per hectare. It is important we don’t start to see system drift.
“Grass and clover management will become increasingly important.
“Healthy soils will underpin the profitability of our systems. We need to maintain productive agricultural systems to ensure we can feed the world,” she added.
Approximately, 90% of land in Ireland is in grass which provides huge scope to sequester carbon at a national level.
“Agriculture and the environment can have a very symbiotic relationship in the future,” McEvoy added.
The Germinal Ireland representative also highlighted the importance of using the Pasture Profit Index for grass seed to select top-performing varieties.
There is a €157/ha difference between the best and the worst perennial ryegrass on the list, she revealed.
Role of red clover
Dr. Nicky Byrne, from Teagasc Grange, confirmed that red clover could play a key role in helping to lower nitrogen use while maintaining or even increasing sward and animal performance.
Since 2019, the management team at Teagasc Grange has reduced chemical nitrogen (N) from 250kg/ha/year to 120kg by incorporating white and red clover into grassland.
Byrne explained that red clover could biologically fix up to 300kg of N/ha. But swards needed careful management to achieve good yields and persistency.
He encouraged farmers to select varieties for good persistency after year three, and sow red clover alongside good quality perennial ryegrasses and white clover to bridge the gap when red clover diminishes in the sward.
New developments in plant breeding
Dr. David Lloyd, head of plant breeding at Germinal Horizon – which is part of Aberystwyth University in Wales – explained how Germinal is developing improved varieties of red clover to improve persistency.
One of these is RedRunner; it has a stoloniferous growth habit like white clover.
Lloyd referred to this specific trait as being “revolutionary in grassland agriculture”.
“Not only does it have improved grazing tolerance, but it also reduces ammonia losses,” he said.
“When leaves are damaged during grazing or when clover is ensiled, it produces compounds that bind to proteins making them less vulnerable to degradation by fermentative processes.
“Therefore it reduces the loss of nitrogen as ammonia and increases protein available for use by the animal.”
RedRunner is one of the varieties being developed as part of the Nitrogen Utilisation Efficiency-Legume (NUE-Leg) project which has recently secured €4 million in grant supports from the UK Department of Environment, Food and Rural Affairs (Defra) for its next on-farm trial phase.
Project NUE-Leg seeks to combine newly developed legume varieties with selected soil microbes and bespoke plant nutrition programmes to achieve a three-fold increase in fixing atmospheric nitrogen.
Cover crops
Soil scientist Neil Fuller, from the Atlas Sustainable Soils Program, talked about the role of cover crops in retaining nutrients, like nitrogen, while also building a ‘brand new proposition’ for agriculture in helping to mitigate climate change.
“The only piece of the puzzle that can get involved with carbon removals is farmers because they have land and that’s a unique proposition. The whole thing pivots around soil sequestration,” he explained.
Trials have confirmed that growing multi-species cover crops for 90 days after barley harvest retained 120kg of N and 32kg of phosphorus, three years of data showed.
“If it’s green, it’s growing, it’s multispecies, it’s really climate-friendly and farmers are taking the first steps towards climate-smart farming,” Fuller said.