Multi-species grass seed mixes are increasing in popularity thanks to the benefits they bring to livestock performance, soil health, and biodiversity. Currently, mixes are most often used in sheep or low-input beef enterprises, but are rapidly gaining interest in the dairy sector, too.
What is a multi-species grass seed mix?
A multi-species mix includes at least one type of grass, legume, and herb. The different characteristics of the varying plant types work together to maximise the use of light, moisture, and nutrients above and below ground.
As with traditional grass and clover mixes, high-sugar grasses provide the basis for performance, supplemented with the protein from legumes and their palatability to increase dry matter intakes.
The addition of herbs provides further protein, energy, and trace elements, with their drought-resistant properties helping to produce feed when ryegrass and clover production dip.
Dr Mary McEvoy on multi-species
“Plantains and chicory are the leading forage herbs in multi-species, as they cope well within a competitive sward and perform consistently across soil types,” explains Dr Mary McEvoy.
“In terms of legumes, red and white clovers are used most often but more complex options include birdsfoot trefoil, sainfoin, and alsike clover. All bring different attributes; alsike clover for example tolerates more acidic soils and wet soils better than conventional white clover and sainfoin has anthelmintic properties.”
What are the benefits of multi-species swards?
1. Prepare for the weather
With ever-changing weather patterns, introducing more species into a sward helps regulate forage availability at either end of the season and provides ongoing herbage and dry matter in times of drought.
2. Improve soil health
The range of plants in a multi-species mix provides root systems working at various soil strata, bringing trace elements to the surface and helping soil structure and fertility.
3. Enhance biodiversity
Environmentally, more species in a field means more opportunities for biodiversity, attracting additional insects to the crop.
4. Nitrogen-fixation from clover
Legumes, such as clovers, have valuable nitrogen-fixing properties reducing a farm’s dependence on bought-in nitrogen.
5. Clover persistency
The increased persistency seen in modern varieties of red clovers means they yield effectively into their third, fourth, and fifth seasons, building soil fertility and structure.
6. Plantain drives sheep performance
Plantains are particularly effective in driving performance in sheep. They emerge early and their perennial leafy forage is highly palatable, providing ewes with more milk to produce heavier lambs at weaning.
7. Red clover for lamb finishing
Red clovers continue growth into the autumn, providing excellent feed to finish lambs, so multi-species are a good option for those looking to buffer the shoulders of the season. Red clover contains phytoestrogens, though, which can impact ewe fertility. Avoid putting ewes on these leys six weeks pre- and post-tupping.
Are there any limitations?
As a rule, multi-species grass seed mixes are suited to lighter, drier soils. While herbs tend to thrive in periods of drought, they can fail in waterlogged or heavier soils. But, in terms of longevity, the herbs within a ley are expected to persist for up to five years.
There are no options for weed control once a multi-species sward is established so it’s important to address any issues prior to sowing. For optimum establishment and persistency, soil fertility must be good, with a pH of 6.0 or above and mixes should be sown in warm spring soils or from June to August.
What Irish farmers need to know about multi-species swards