Webinar: Are multi-species swards right for your farm?

On Thursday 24 March 2022, Germinal experts Ben Wixey and Dr Mary McEvoy hosted Professor Tommy Boland for a webinar discussing the potential of multi-species swards.

Below, you can watch the webinar and read through the detailed questions and answers that were compiled by our viewers and the panel.

Watch: Are multi-species swards right for your farm?

Multi-species swards Q&A

If you want to control weeds pre-oversowing, which spray has the best kill on dock but has the shortest residual period?

I am not a qualified agronomist, but I am aware that there are significant periods that need to be observed after spraying before legumes or herbs can be included – please ask a qualified agronomist.

The bigger question is: Will multi-species seeds establish into an existing sward? There will but much competition from the existing sward that will out-compete a small-seeded herb or a young seedling.

If the existing sward is open and full of perennial ryegrass (PRG) with good soil pH and P & Ks, then there is a chance. But, if it is an old "feggy" sward, then stitching into it is not that successful in our opinion.

If not covered tonight, could you please advise on the application of farmyard manure to MSS? Advisable, when in season? Things to avoid?

There will generally be no different advice on applying farmyard manure to a grass sward. Well-rotted and broken-up manure can be applied in the seedbed and friable manure could be applied to the growing crop, but it would need time for the weather to break it down before grazing.

What are the costs of seed per acre between the different multi-species seed mixes?

The costs of herbs and clover seeds per kilo are far more than the price of perennial ryegrass and Timothy. Therefore, yes, it is more expensive if you have the same seed rate.

However, the big advantage is the seeds are small. So, in a kilo, you get about twice the number of seeds as a tetraploid perennial ryegrass seed. You are also not looking for a full sward of herbs but a nice balance between grass and herbs and clovers. I would suspect on average about £20/€20 per acre more for a multi-species grass seed mixture.

Are multi-species grass seed mixtures more expensive than perennial ryegrass-clover seed mixtures?

Please see the answer above.

How much nitrogen were you applying per acre or per hectare to the pure perennial ryegrass sward on your trial to get 14.5 tonnes of dry matter per ha?

The standard fertiliser rate was 150kg N/ha. To simulate grazing returns, the increased rate was 250 kg/ha. The results presented in the webinar were a combination of results under these two fertilisers regimes.

Are you able to put a value on cover kg/DM/ha for ‘don’t overgraze’? Grazers on dairy typically hit the first round of grazing in the spring and the last in autumn hard, which could adversely affect sward composition?

Yes, there’s slightly different advice due to crowns of some of the herbs and clovers, particularly chicory and red clover. If the multi-species sward has a large percentage of perennial ryegrass in it, then tighter grazing can be achieved. But, overall, the advice would be not to overgraze as you will take out the herbs. We would not give a cover DM value as it is difficult, if not impossible, to use a plate meter with a "strong" multi-species sward, but we would recommend not grazing below 7cm.

Can herbs be overseeded in years three-plus?

In the right conditions, yes, but it is very difficult as the herbs are slow to establish and have very small seeds. If the existing swards are open and have good pH with good P&K, then it is possible to have success with multi-species overseeding, but it is a risky operation.

Bearing in mind the likely Sustainable Farming Incentive (SFI) requirement for 15% of an area as a multi-species sward, are you suggesting this can only be achieved by a full reseed rather than oversowing?

The short answer from us would be yes, but please see the answer above regarding overseeding multi-species. My question would be is it worth the risk on your SFI payment if it is unsuccessful?

You mention that red clover had a lower protein level than white – is this typical?

Generally, yes, red clover would be in the high teens in terms of protein content and white clover would be in the twenties, but it depends, of course, on the growth stage. The advantage of red clover is it has two-to-three times the dry matter content of white clover and is compatible with PRG for timings with silage management.

If you have weeds, do they take over the multi-species swards over time under management in Wiltshire?

The eight or nine cutting method used to simulate grazing is controlling most of the weeds. There are more weeds in the more open 16 species mix with less PRG that acts as ground cover. This is because the other grasses, Fescues, Timothy and Cocksfoot are slower to establish and give more opportunity for weeds to establish.

Good establishment of your multi-species sward is important. If it is slow to get going, the weeds get more of an opportunity. So, the timing of sowing and ensuring soil fertility is optimum, and that the weather is in your favour will be important.

When you say to control weeds before sowing, how is this done when you till the soil to bring up a new weed burden?

I would recommend creating a stale seedbed as I would for lucerne. Prepare the seedbed in a normal way, including rolling firm. Then shut the gate for two-to-three weeks until all the weed seeds in the soil have emerged and then burn those off with glyphosate and drill into the surface of the seedbed and roll one last time.

The secret to this method is timing, both for the application of glyphosate and the drilling. A warm seedbed and moisture at this stage will be critical.

What is the likely persistence of multi-species leys? We know PRG plus Aber white and red clovers are very productive for five years. Will the other species stick it that long?

In general, multi-species swards would last two-to-four years. Less intense grazing and not damaging the crowns of the plants in autumn, winter and early spring is vitally important. Chicory has relatively low persistency.

What are multi-species swards like for winter grazing? Any advice on management for the winter on a farm with all MSS fields?

As above, do not overgraze. The crowns, growing points of chicory and clovers, are delicate and damage from sheep grazing or treading from cattle hooves in wet weather will damage and cause death to those plants.

Did you have any control plots with no nitrogen used?

No, we didn’t work this into the trial’s protocol at the start as it is another whole set of repetitions. But, in hindsight, it would have presented useful information and is likely something we will do in the future.

Is there any organic growing trials data available of multi-species swards been carried out to date?

I am afraid we don't have any.

Why aren't you testing for growth with no chemical fertiliser?

After a busy initial trial, we will be looking at it in future.

Do multi-species swards reduce bloat incidence in high clover swards?

I am not sure we have any evidence of bloat reduction, but a more balanced diet should help. We would recommend a cautious approach to multi-species grazing if the animals are not totally used to high clover swards. Avoid turning out hungry animals to swards with a high clover percentage and monitor stock where there is a risk.

Can white clover seed be stitched into a permanent pasture that has been well grazed down and harrowed? How long should it be left until it is grazed by sheep?

Yes, it can work, but please see my previous comments. The secret would also be timing with white clover. Drill into swards in the summer when the grass growth is slightly slower the day length is long and the soil temperature is at its highest. Make sure there is moisture around and do not bury the seed too deep, 1cm or on the soil surface, and then roll in tight. We would say go in April/early May as there is a better chance of moisture. Soil fertility needs to be good. Frequent grazing at low covers after sowing to "check" the grass and ensure the clover can access light and is not smothered by the grass is important.

Did you compare a mix of PRG, white clover, Timothy and Cocksfoot with a straight PRG or a PRG/WC mix?

I am afraid we did not at this stage.

Why do you think that the multi-species silage performs better than it analyses?

We are not totally sure; we think it might be to do with the calibrations on high-protein samples using NIR. And it might also be to do with the PPO (Polyphenol Oxidase), which is an enzyme that protects the protein through the rumen and is then broken down and absorbed more efficiently in a lower stomach.

Tommy: Not exactly sure, but our work on feed intake and digestibility which will take place later this year, will hopefully shed some more light on this.

Could you undersow multi-species with wheat/barley for wholecrop production?

Yes, I can't see any reason why not, but remember the multis-species is the key crop. Don't be too greedy with the wholecrop. Cut the seed rate right down to allow the multi-species sward to establish against it. The slower establishment of some of the herbs might be a problem with a fast-germinating cereal crop as a cover.

What do you think of undersowing with Redstart hybrid brassica seed?

Yes, again this is possible, but be careful not to use more than 1/4 kg or 1/2 lb in old money. The Redstart hybrid brassica is quick to emerge and could smoother the slower establishing elements.

Make sure it is grazed off in good time with a large number of lambs on a small area for a small amount of time and then move them on. And make sure the multi-species sward can stand the pull test (i.e. grab the forage and make sure the leaf rips rather than the seedling coming out by the roots).

Can I set stock sheep, and mixed stock graze?

To be honest, this wouldn’t be ideal. We have seen stock preferentially graze out some of the smaller herbs and clovers. I think multi-species rotational grazing or mob grazing would be better.

How do multi-species perform in heavy soil types? Would heavy farms expect a later spring turnout and earlier winter housing than perennial ryegrass swards? Does the surface growing point of red clover and Plantain mean that extra care should be taken to avoid poaching?

Yes, in short, to all your comments. The soil conditions would delay spring growth and be more at risk of causing damage to some elements. Please avoid poaching and increase the content of PRG for ground cover. The plants will grow but the management will be more difficult. Herbs and red clover are not very tolerant of poaching.

Will cows adjust to the sward if it’s a small proportion of the grazing block?

This is a challenge with dairy cows. Sometimes, herbs left too long between grazing can become strong and stemmy, particularly chicory, and can then become bitter.

If you are rotationally grazing multi-species with dairy cows, then I would suggest PRG, maybe Timothy, white clover red clover and plantain, and leave it at that.

Ideally, use multi-species for a group of animals and leave them on it for as much time as possible to minimise changes to the diet (e.g. weanlings).

Are there any BASIS points available for this webinar?

No, I am afraid not on this occasion.

At University College Dublin (UCD), did you look at adult parasite burdens in the sheep at slaughter after grazing multi-species swards?

No, we didn't assess the level of parasitism within the animals at slaughter.

At UCD, is that multi-species silage you fed, pit or bale?

Bale.

Is UCD measuring if there is any carbon sequestration between each sward?

Yes, but this is a very long-term measurement timeframe and we don't have any data yet.

Is it a fair comment that 12.5 ewes and lambs per hectare is a low stocking rate? Nearer 20 on ryegrass/white clover leys in Southern England with March/April lambing?

It is location dependent as to what a high stocking rate (SR) is. In Ireland, the average SR on sheep farms is 7.5 to 9 ewes/ha, so in that context 12.5 is high.

For any questions regarding multi-species grass seed mixtures, sowing, establishment or grazing, please ask a Germinal expert.

Multi-species grass seed mixtures

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