Establishing Multi-Species Swards on your Farm

By Aoife Forde, B&T Drystock Adviser, Teagasc Galway/Clare

The growing of multi-species swards has gained much attention in recent years. Multi-species swards consist of a variety of plants from different families including clovers, grasses, brassicas and herbs. The benefits of a multi-species sward is that they require reduced fertiliser while maintaining a steady growth rate. A sward with a clover content of between 20-50% can allow fertiliser application in the summer months to be halved. The inclusion of Plantain and Chicory in multispecies mixes can prevent losses of nitrogen on the farm through better use of N by animals and reduced farm leaching. 

The recent Department of Agriculture multi-species sward scheme showed a good interest from farmers for sowing these swards. Below is some information about how to establish multi-species swards on your farm.

Choosing a Site and Preparation:

Choose grazing paddocks over silage fields and choose paddocks with low weed burden.  Avoid commonage and land designated as Natura 2000 as they are excluded from the DAFM scheme.  Also avoid replacing areas of existing biodiversity (naturally diverse permanent pasture that is not designated) or unused land on the farm with new multi-species swards.  It is important that soil fertility is good i.e. pH 6.2-6.5 and Index 3+ for P & K.  The seed mixture required for the DAFM scheme is listed below.

Weed Management:

Address weed issues with herbicide before sowing.  No post-emergence spray can be applied to the whole field once multi-species / clover swards are established.  After reseeding, the only methods for weed control are either spot spraying/weed licking/wiping (using a spray that targets the most prevalent weed e.g. for thistles use “Thistlex”), mechanically picking/removing weeds or regular topping to reduce annual weeds. Direct drilling results in lower weed emergence as does good establishment. 

Method of Reseeding:

Similar to grassland reseeding, best conditions for sowing are without drought or frost, and ideally a warm, moist seedbed (~10°C) between April and August.   

Plough/Till/Sow:

• Spray-off the existing sward as per normal reseed. Then cut the existing sward as tight as possible while complying with the prescribed interval between spraying and cutting.
• Cultivate soil as you choose (disc/harrow/plough)
• Lime should be applied, if necessary.  If using minimum cultivation apply 5 tonne of lime per hectare to the desiccated sward pre-cultivation.  If ploughing address any lime requirement post-ploughing.
• Apply normal seed bed fertiliser at sowing (P and K with N) based on soil test results.
• Sow the multi-species seed mix at a rate of 12kg/acre (30kg/ha) at approx. 1 cm deep (choose seeder carefully to avoid seed separation).
• Roll to get fine firm seed bed and good soil and seed contact.
• Allow 6-8 weeks before the first grazing to let herbs establish strong taproots, only graze if new plants are strong enough to withstand grazing

Direct Drilling into Stale Seed Bed/Minimum Cultivation:

This is environmentally beneficial because it retains more soil organic matter than a full reseed.

• Graze/cut off existing sward as tight as possible,
• Spray-off with glyphosate as per normal reseed,
• Comply with the interval between spraying and grazing/cutting prescribed on the herbicide label.
• Sow at approx. 1 cm deep (choose drill carefully to avoid seed separation)
• Roll to ensure soil and seed contact
• Seed bed fertiliser and lime as normal for reseed
• Allow 6-8 weeks before the first grazing to let herbs establish strong taproots, only graze if new plants are strong enough to withstand grazing

Over-Sowing into an Existing Sward:

Over-sowing into an existing sward is another option but can be less reliable than a full reseed.  It has the advantage of being cheaper, taking fields out of production for a shorter duration, and better protecting soil carbon. When done correctly (and with favourable conditions), it can be very successful.  However, for the DAFM MSS Scheme, the grass component must be included as part of the seed mix, so over-sowing will be a less relevant option.  Note that the principles are almost identical to those for over-sowing of clover into a grass sward.  

For further details on multi-species swards check out the Signpost factsheet on multi-species swards at:  www.teagasc.ie/signpost.