Throughout the week we have got an insight into multi-species swards from the components of a mixture to establishment and management on farm. While sowing a crop that has no available weed control or requirement for artificial nitrogen may seem strange, there are a whole host of benefits from using multi-species swards. These benefits include
Maintaining forage yields while greatly reduced nitrogen fertiliser use
Improved animal performance and health
Enhanced soil quality and reduced GHG emissions
Both Karol Kissane and Kevin O’Hanlon have witnessed these benefits first-hand with their multi-species swards producing the same amount of forage as grass swards but without the need for nitrogen fertiliser. For example, Kevin has skipped 4 rounds of fertiliser application since sowing his mixture in June. This kind of cost-saving represents a significant amount of money when scaled up over 20, 30 or 40 acres.
In addition, the forage is of excellent quality with the mixture of grasses, legumes and herbs providing a balanced diet that is high in protein, vitamins and minerals. This represents further opportunity for cost-savings on bought-in feed, minerals and anthelminthic dose.
With potential for savings like this and the positive knock-on effects on the environment, multi-species swards represent a very important tool in achieving real sustainability, both financially and environmentally, in Irish meat and milk production.
Karol and Kevin have seen the benefits multi-species swards can bring to a grass-based production system and intend to increase the area of multi-species swards on-farm this year.
If you intend to experiment with a few acres of multi-species this year then remember the following important tips:
•Before sowing, address any weed problems in the field as once the seed is sown there are no herbicides available for multi-species swards.
•Sow into a fertile, fine, firm seedbed. Rolling is important to ensure contact between the small seeds of legumes and herbs and the soil.
•Rotational grazing is best to prolong persistence
oIncreasing the rotation length to 28 days will also help persistence
oAs will grazing to 6cm
•Reduce N. Any N (up to 50kg N/ha) should be applied in early spring to boost grass growth.
oLarge applications of N in summer will reduce legume and herb persistence
oSlurry is an ideal source of N in spring
There is great interest in multi-species swards across Ireland and if the benefits seen in these early stages persist into the future these swards will no doubt play an important role in Irish agriculture.
Multi-species swards have the potential to produce high yields of quality forage at greatly reduced rates of nitrogen fertiliser input.
As well as providing excellent quality, mineral-rich forage in the summer months, deep-rooting herbs like ribwort plantain and chicory are extremely drought tolerant, which is an increasing concern for many Irish farmers.
Multi-species swards can produce similar DM yields to perennial ryegrass swards at significantly lower rates of inorganic N fertiliser. This could be worth up to 7 bags 18.6.12/acre or €120/acre per year.
The inclusion of warm-season species like chicory and plantain means multi-species swards have strong summer production compared to a grass sward. Furthermore, these deep-rooting species make the sward much more tolerant of drought than a grass sward.
The use of multi-species swards compared to grass-only swards in agriculture can also provide a wide range of environmental benefits, including:
Reduced N2O emissions and nitrate leaching associated with reduced fertiliser use.
Higher rates of carbon sequestration due to deeper root-depths
Enhanced biodiversity, particularly pollinators feeding on the variety of flowering plants in multi-species swards.