Multi-species swards include grass, legume and herb components, that bring different characteristics and make maximum use of resources, according to Germinal’s technical development manager, Dr. Mary McEvoy.
“There are multiple benefits of multi-species which are well-proven from a scientific perspective,” Dr. McEvoy said
Germinal’s multi-species mixture includes perennial ryegrass with white clover as the legume element, plus the herbs, chicory and plantain. Adding more species brings more characteristics and can fine-tune suitability for different grazing systems.
“Essentially, some species are more suited to intensive grazing than others, so it’s about identifying what’s going to work on your particular farm,” she added.
Soil conditioning
A multi-species mixture aids soil conditioning, with different root structures helping to break up soil compaction and aerate the soil, improving drainage and biological activity.
The resulting improvement to organic matter content contributes to the overall health of the soil and its ability to sequester carbon, compared to single species swards.
Deeper rooting species are more tolerant to drought, McEvoy explained. The ability to reach moisture from lower in the soil allows them to maintain a relatively stable yield through the summer and especially during dry spells.
Varied rooting systems the species harvest minerals from different layers of the soil. “Legumes for example, would generally be considered high in copper, cobalt, zinc and iron and herbs tend to be high in iodine and selenium,” said Dr. McEvoy.
Nitrogen reduction
Another benefit is the reduced need for nitrogen, predominantly due to the nitrogen-fixing qualities of clover. Dry matter (DM) production from a multi-species sward is better at low nitrogen inputs compared to grass-only swards.
Less nitrogen means lower emissions and reduces the possibility of leaching, McEvoy added.
“We also see improved biodiversity with multi-species mixtures, both above and below ground.” This includes earthworm and insect populations which also have a positive impact on birdlife.
The resulting forage is high in protein and highly digestible, said Dr. McEvoy. Research has shown impressive improvements in the growth rates of lambs grazing multi-species swards.
Trials from University College Dublin (UCD) showed lambs reaching finished weight 25 days earlier than those on perennial ryegrass only swards.
Research looking to quantify the effects of multi-species grazing on the performance of dairy herds is currently underway, but many farmers report these mixes are helping them manage drought and produce consistent forage in challenging weather conditions.
“Different species do well at different times of year; some are better in spring, some in mid-season or in dry spells. That’s where we gain the stability to help maintain a steady food supply across the year.”
Further benefits of multi-species swards
Other benefits to livestock include a reduced worm burden, says Dr. McEvoy. Chicory and sainfoin in particular are known for their anthelmintic properties and could help reduce the requirement for worming products.
This is particularly pertinent given the evidence for increasing resistance to wormers, she adds.
One concern with multi-species swards is weed ingress because, once sown, there are few options for weed control.
“But what we are seeing in reality is when you have a number of species competing for light and nutrients, they are able to out-compete weeds such as docks, so there isn’t the same need for weed control,” Dr. McEvoy added.
However, it is still important to address any weed issues prior to sowing. For good sward establishment and persistency, it is important to pay attention to soil fertility with a minimum pH of 6.0. Multi-species mixtures should be drilled into a warm soil between June and August.
For more information on multi-species swards; click here or call; 0504 41100.
