Multispecies Sward animals have an approximately 15 percent reduced carbon footprint compared to animals bred on perennial ryegrass, according to rigorous research at UCD’s Lyons Farm.
r Helen Sheridan, associate professor at the UCD School of Agriculture and Food Science, says several studies on the effects of multispecies turf — including perennial ryegrass, timothy, white clover, red clover, chicory and plantain — increased DM production from herbs have shown reduced fertilization inputs, improved animal performance, reduced greenhouse gas emissions, improved economic performance and improved biodiversity (compared to ryegrass monocultures).
Speaking at last week’s UCD symposium on meeting the agricultural sector’s climate targets, Dr. However, Sheridan also warns that multispecies grasslands are better suited to intensive rather than extensive farming systems.
She outlined 10 years of research on three specific projects and said there were “big wins”.
“The Smartgrass project found that legume-fed lambs finished about two weeks earlier than monoculture lambs. So that’s a two-week shorter lifespan, less time for methane production, and less handling by farmers.
“More excitingly, lambs grazing on multispecies pastures require 50 percent fewer dewormers over their lifetime compared to lambs grazing perennial ryegrass.”
On the performance of males from the dairy herd grazing at a stocking density of 2.5 LU/ha as part of the Smartsward project, said Dr. Sheridan: “Nevertheless, multispecies turfs produced 2.5t forage DM/ha compared to ryegrass turfs receiving only 40 pcs of fertilizer N/ha – a big win.
“Days to slaughter were also significantly reduced by about a month compared to ryegrass monoculture cattle…that’s a month less methane production,” she said.
“Smartsward then found a drop of about 45 percent in CO2 equivalents per kilogram live weight of beef compared to the national average.
“There was a further 15 percent drop between the three Smartsward systems when comparing the ryegrass monocultures to the multispecies and ryegrass clover turfs. This was largely based on reduced slaughter days and fertilizers.
“So the animals grazing the multispecies and the ryegrass and clover grass meadows had about a 15 percent reduced carbon footprint compared to the ryegrass animals.
“In terms of economic benefits, there was a 68 percent net margin increase compared to perennial ryegrass, which in turn is largely related to the reduction in fertilizer nitrogen… but these numbers are based on conservative fertilizer prices.”
Finally, at the Heartland project, the multispecies turfs again produced more herb dry matter from lower fertilizer N inputs, and heifers grazing a six-species mix had a 17 percent higher average daily gain compared to those grazing perennial ryegrass and permanent pasture grazed.
“Overall, it’s a really positive picture in terms of how minimal biodiversity improvement on these grasslands really benefits many different sustainability measures,” said Dr. Sheridan.
“But I see the role of multispecies very strongly in relation to high-input, higher-intensity systems.
“More extensive systems are hugely important for biodiversity conservation and we need to recognize and reward the provision of that biodiversity as a result of the farming system, much like meat and milk, which would give farmers a way forward to more extensive systems. “
