Why should you sow a Multi-species sward?

 

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
o Increasing the rotation length to 28 days will also help persistence
o As will grazing to 6cm
Reduce N. Any N (up to 50kg N/ha) should be applied in early spring to boost grass growth.
o Large applications of N in summer will reduce legume and herb persistence
o Slurry 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.

 

Links to Multi-species Research