Advice on establishing and grazing herbal leys

A herbal ley is a diverse sward that includes different grasses and species, with varying rooting depths, properties and drought tolerances.

They have a positive effect on soil health, structure and drainage and usually include nitrogen-fixing legumes, which are high in protein and tannins, and have huge potential for carbon sequestration.

Herbal leys also provide a very rich mineral feed for livestock – the mineral content is much higher than a ryegrass mix and can carry 60% more calcium.

Below, Anthony Ellis and Tom Tolputt from South West Farm Consultants explain how to establish and maintain herbal leys.

See also: Why herbal leys have been added to arable rotation trial

Advice on choosing the mix

You must build the mix to suit your soil type and what you want to achieve.

Perennial ryegrass is the mainstay of most medium- to long-term herbal leys, as it gives the bulk of dry matter, germinates quickly, protects the soil and allows the herbs to establish.

Italian ryegrass is not suitable due to its short-term nature (it generally only lasts two years). It might also outcompete the herbs and can be difficult to grow, especially in hotter conditions.

Other grasses to consider include:

  • Cocksfoot This is deep-rooting and grows over a slightly longer season, allowing for extending grazing.
  • Timothy Most higher-production grasses need temperatures to be higher than 5-6C to grow, but timothy will grow at a degree lower than this. It is also very palatable, which encourages the animal to consume more dry matter.
  • Festulolium A hybrid of fescue and perennial ryegrass it offers the best of both worlds combining stress resistance of fescue with the bulkiness of ryegrass. Although it’s important to check the parent material, as that will influence whether it is more similar to a ryegrass or a tough fescue.

There are a range of different grass, legumes and herbs that can be used. See table below for options.

Advice on establishment

Herbals leys need little fertilisation; with 30% legumes in the mix, they will be self-sustaining. This means they fit nicely into arable rotations, because they build soil carbon, fix nitrogen and mobilise phosphate for the next crop.

However, they can be tricky to establish. Nothing should be drilled deeper than 1cm and the soil should be rolled for good seed-to-soil contact. If you’re in doubt, roll it again.

Herbal leys are slow to emerge, so undersowing them with 100kg/ha of barley makes a good growing environment.

Advice on grazing livestock on herbal leys

From an animal nutrition perspective, livestock are very content on herbal leys, but they must be carefully managed.

Livestock naturally select the most palatable plants, so if you’re not careful, they can graze certain species to extinction.  

Therefore, it is best to rotationally graze fields rather than set-stock animals to allow it to be grazed evenly and rested.  

Ideally, fields should be left empty for 28-35 days to allow for sufficient recovery. This is a slightly longer rotation than ryegrass, but it will provide a lot more nutrition.

It is also important to graze leys lightly in the first year to encourage tillering and prevent plant damage.

Herbal ley species

Name

What is it?

Root structure

Soil type

Benefits

Persistence

Yield

Grazing/cutting suitability

Cocksfoot

Grass

Deep-rooting

Offers continued growing in dry weather when grown on dry and free-draining soil 

Early and extended grazing, quick recovery

Very persistent

Good

Good, provided it is grazed hard

Not good for long-term pasture, as it can become clumpy and unpalatable

Varietal choice important

Timothy

Grass

Fine, shallow, fibrous roots

Will grow well on heavy or light soil

Disease free

Very persistent

Good

Can be made into silage, hay or grazed

Meadow fescue

Grass

Medium to deep

Will grow on nearly all soils, from brash to clay

Long duration and drought-tolerant alternative to perennial ryegrass

More persistent, but similar growth habit as perennial ryegrass

Fair

Often sown with Timothy for hay or grazing

White clover

Legume

Deep taproot during establishment, replaced by shallower, fibrous roots and stoloniferous growth when mature

Grows on nearly all soils

Drought-resistant

Fixes nitrogen

Palatable

High protein content

Spreads and increases in the sward due to stolons over time

Good ground cover

Very persistent

Increases overall forage yield

Best grown with grasses

Can be cut or grazed

Ideal for grazing – extra protein increases liveweight gain

Very palatable

Red clover

Legume

Deep taproot

Grows on nearly all soil types, apart from very acidic soil, where alsike clover should be used

High-yielding

Less persistent than white clover, lasting between two and four years

Produces one-third more yield than white clover

Normally used in silage, but it can be grazed with careful management

Best sown with aggressive ryegrasses

Contains oestrogen, so move breeding animals off red clover around conception

Alsike clover

Legume

Medium

Good for acidic or heavy soils

Works in some soils that red clover might struggle in

Three years

 

Slightly lower-yielding than red clover

Slower to grow than red clover

Lucerne

Legume

Deep-rooting

Dry, calcareous soils, free-draining, not acidic

Protein-rich

Drought-resistant

Useful complement to maize silage

Fixes nitrogen

Perennial, varies according to soil suitability

 

14t DM/ha without nitrogen on dry land

High enough yield to be grown on its own

Usually sown with a companion grass such as Timothy or meadow fescue

Cut three times a year

Can cause bloat if grazed

Sainfoin

Legume

Deep roots  leave soil in great condition

Never stops growing – even in dry spells

Grows on thin, alkaline soils such as dry chalk or limestone

High in protein

Efficiently used by stock

Very drought-resistant

Pollinators love it

Great for grazing and cutting

Anti-bloat

Natural anthelmintic

Fixes nitrogen

Perennial, varies according to soil suitability

Good yields when well established, equal to that of lucerne

Can be cut

Contains tannins, which help protein absorption, leading to higher liveweight gains

Doesn’t cause bloat

May reduce methane emissions

Acts as an anthelmintic 

Yellow trefoil

Legume

Shallow

Establishes well when undersown

Sheds seeds freely, so is regenerative

Hardy annual (will survive a winter or a grazing)

Adds diversity

Gives early spring growth, which is unusual, as legumes are normally late to grow

Birdsfoot trefoil

Legume

Shallow

Suited to poor and dry soils

Anthelmintic

 

Four to five years

Works well as part of legume mix

Cut and graze

Contains tannins and may have other medicinal benefits

Chicory

Herb

Deep-rooting

Can grow very well on dry soil

Can penetrate plough pans

Good source of minerals

Has anthelmintic effects

Perennial

High-yielding

Mainly for grazing, but can be cut occasionally – watch out for wrapped bales with chicory stalks

Ribgrass

Herb

Deep-rooting

Grows well in compacted or dry ground

 

Reliable

Grown for vitamin and mineral content – calcium, copper and selenium

 

Perennial

Low-yielding

Cut and graze

Yarrow

Herb

Deep-rooting

Works well in certain mixes

Rich source of vitamin A

Perennial

Low-yielding

 

Mainly grazing

Burnet

Herb

 

Good for dry soils

Extremely drought-resistant

Perennial

Low-yielding

 

Very palatable

Mainly grazing

Sheep’s parsley

Herb

Medium

Light soils

Works well in mixes

Perennial

Low-yielding

Mainly grazing

Source: Cotswold Seeds

Case study: Peter Cheek

Using herbal leys is helping dairy farm manager Peter Cheek to maintain good growth rates during drought.

He has been growing herbal leys for two years in a field lab trial with the Innovative Farmers programme.

He sows 31ha of herbal leys, using a Cotswold Seeds mix comprising cocksfoot, perennial ryegrass, timothy, meadow fescue, tall fescue, red clover, white clover, alsike clover, sweet clover, birdsfoot trefoil, sainfoin, chicory, ribgrass, burnet, yarrow and sheep’s parsley.

Peter Cheek in a field

Peter Cheek

Farm facts

  • 445ha – 31ha in herbal leys, 41ha of permanent pasture, 161ha arable land and the rest is grass/clover leys
  • Runs 287 cows plus followers
  • Rears all replacements
  • Uses sexed semen
  • Spring and autumn calving
  • 50% of milk goes to Bruton Dairies, with the other 50% sent to Omsco for cheese
  • Four cuts of silage a year from red clover leys
  • Cows fed on total mixed ration
  • Norwegian Reds, Flekviehs, Normandes and British Friesians

The ley is established with a pea-barley mix in mid-April. Then, once the wholecrop has been harvested, Mr Creek lightly grazes cattle on the crop in September and October.

Close-lying land is in a rotation including four years of a white clover or herbal ley. This is ploughed in the spring and followed by spring wheat or barley.

After harvest, an autumn cover crop of Westerwolds is min-tilled into the soil and is either grazed or cut for silage in the spring.

It is then disced, ready for the pea-barley mix to be undersown and rolled in mid-April.

Offlying land is put down to three years of red clover, then winter wheat, winter oats, and the “Vast and Fast” mix from Cotswold Seeds.

This is followed by another cereal before going back into pea barley mix, undersown with red clover.

“We haven’t measured any specific benefits [to the herbal leys], but the milk yield was maintained when we switched from ryegrass,” says Mr Cheek.

“For two years, we have had drought, and without the herbal ley we would have been in serious trouble.”

Benefits

  • Deep-rooting varieties offer extended grazing in drought periods
  • Timothy is disease free and very persistent
  • Extra protein increases liveweight gains
  • Improves soil structure, health and drainage
  • Can grow on various soil types
  • Tannins reduce worm burden
  • Good mineral content; vitamin A, calcium, copper and selenium