Permanent pasture- the hidden Jewel on the farm

I am delighted to be speaking at Groundswell again, this time alongside Sally-Ann Spence, the dung beetle expert. Join us at 15:00 on Wednesday 1st July in the PFL tent.

I will be exploring the value of permanent pasture as a farm resource, and how looking at it differently, can help farmers reduce costs, improve resilience, and strengthen long-term sustainability.

A new reseed often performs well for three to four years before vigour declines and it is gradually overtaken by “weed grasses” and broad-leaved weeds.

During establishment and beyond, bare patches between young plants can leave soil exposed. This not only increases oxidation and soil erosion but also allows the surface to become much hotter where there is no forage cover. As a result, the soil can heat up, increasing water loss through evaporation and placing additional stress on the grass sward.

When I first visit a grass farm as an advisor , I look closely at the species growing in the hedgerows. These plants often reveal what is best suited to the local conditions, soil type, and aspect. While greater production may be the goal, it is important not to lose sight of the resilient core species that survive naturally. It is a real hare-and-tortoise scenario: we can reseed every four years to chase output, or we can accept slightly lower production in return for a more sustainable sward with resilience, nutrient delivery, and long-term value. In that context, permanent pasture is king — or queen.

Check for compaction by doing a water infiltration test.

By avoiding unnecessary soil disturbance for reseeding, we can also reduce the risk of slumping as a form of compaction. Other sources of compaction occur from:

·       Traffic from livestock and machinery

·       Heavy applications of aggressive NPK fertiliser

·        Spraying with herbicides or fungicides in a previous crop.

·        Flooding from slurry or floodwater

·        Lack of deep rooting species

·        Continuous overgrazing

With controlled grazing, we can achieve significant gains by feeding the cow and the soil at the same time.

If we sampled a fresh perennial ryegrass plant from root to tip — the way we expect livestock to graze it in order to maximise intake and convert it into food — the result would typically be in the region of 11–12 MJ ME/kg DM. However, if we measured a so-called “weed” grass, or one of the more traditional species such as cocksfoot, timothy, or meadow fescue, using the same cutting and sampling method, the laboratory result would likely be closer to 8–9 MJ ME/kg DM.

However, if we use non-selective method of grazing for a short duration, we can leave a good residual. That residual, with a lower feed value, can be trampled into the soil to feed earthworms and microbes. The remaining plant material available to the animal is then likely to be of higher quality, around 10–11 MJ ME/kg DM.

Changing Grazing or Cutting heights in order to feed the livestock and the soil life also.

Mission accomplished! 

As always, this is easier said than done. There may be a period of adjustment, and some cows may complain at first. However, once they learn they will be moved to fresh breaks more frequently and are no longer expected to graze right down to the floorboards, the system becomes much more effective.

They are likely to be happier as a result.

Whether fertiliser is, in fact, still required is an important question. The answer depends on several factors:

Production expectations and sales requirements

Stocking rates

The availability of natural plant nutrition, including dairy effluent, compost, or other biological inputs

Soil test results indicating the need for corrective amendments such as lime or gypsum

However, straight nitrogen could quite probably be avoided.

It is worth remembering that many weeds are simply:

Seasonal biological indicator species — telling us something we may not want to hear, such as:

Docks = compaction and deficiency in calcium and/or surplus in magnesium

Thistles = compaction & ditto

Buttercups = compaction

Ragwort= poor soil health

Topping can be one of the most effective tools. It allows the root to complete the task the plant is attempting to perform — often breaking up a pan around three inches below the surface. The roots then die back, and together with the cut foliage, they can feed the soil biologically.

Nice "Chocolate cake" like soil found under undisturbed permanent pasture, lots of roots and microbes.

But we do need biodiversity. Biodiversity is what can feed both plants and soil. Anyone familiar with the old GS4 herbal ley or species-rich sward schemes will know that diverse pasture can continue to grow without fertiliser remarkably well — seemingly off fresh air, but in reality, powered by photosynthesis. Look up Jan Baptist van Helmont's 17th-century willow tree experiment or observe any roadside verge full of a mixture of plant species all existing on fresh air (and photosynthesis of course).

A clients sheep grazing unimproved pasture ie made up of couch and Yorkshire fog, by grazing the top 2/3rd and trampling the bottom 1/3rd they can get better grasses growing.

The Ideal Permanent Pasture Sward

A mix of traditional grasses is not a problem, especially where there is some white clover, birdsfoot trefoil, and plantain. In reality, we also have to work with what we are given. Even lower-value fescues can play an important role by keeping the soil covered below grazing residual height. Ideally, we do not want a monopoly of perennial ryegrass, or couch or Yorkshire fog even though they thrive in many conditions; diversity is where the strength lies.

The white clover and other legumes can make a valuable contribution to sustainability by fixing nitrogen with the support of soil microbes. Stitching these species into existing pasture can therefore be a useful and practical way to help the ley as well as pollinators.

Dairy farmers often report mixed responses to permanent pasture: some cows thrive on it, while others are less enthusiastic. Much depends on what else they are offered and how naturally suited they are to grazing. My view is that permanent pasture may often be undervalued in the same way that a New Zealand rising plate meter can overestimate feed availability in Italian ryegrass by around 30%. As a result, pasture allocations may not fully reflect the feed available, and in some cases a herd may appear to make little impact simply because the sward is offering more nutrition and variety than expected — weeds included.

A wild example where there were as many ant hills as head of stock. But thriving on the grasses growing below the tussocks, but still rotationally grazed.

One reason for this talk is that Sally-Ann and I have often seen permanent pasture confined to areas such as banks or archaeological sites, where cultivation is restricted or impractical. In these places, native species have been able to thrive. Yet calves are often set-stocked there and fed concentrates because the sward is seen as unsuitable for growing youngstock. In practice, the calves may stop grazing an hour before the feed truck arrives and resume afterwards, leading the farmer to assume the cake is driving growth rates, when it may simply be replacing the grass, they stopped eating to eat the cake.

Another reason for the love of PP is the sudden arrival of many species of flowers and maybe orchids which will be the reward for longer rest periods, primarily to allow better and deep roots but seeing flora like a burn tip orchid really makes the day !

A fully grown permanent pasture is a sight to see, and it wont deteriorate as fast perennial ryegrass and offers options controlled grazing, hay or silage.

Grazing or a hay cut ? Depend on your context.

With the presence of livestock in an undisturbed environment the likelihood of invertebrates bringing benefits to the sward and soil are much increased. Sally Ann with elaborate on the work invertebrates do.

1 Dung beetles will naturally aerate the soils from the safety of the dung pats and there can be many dung pats left in a paddock after livestock have grazed  these splats of soil nutrition are converted by dung beetles and the like into feed  for earthworms and other invertebrates :

A dung beetle going about converting faeces to food for other invertebrates

1. Earthworms are often the most important biological agents against compaction.

They help by:

* Burrowing through compacted layers, creating channels that improve air and water movement.

* Producing stable casts (worm manure) that bind soil particles into aggregates.

* Mixing organic matter deeper into the soil.

* Creating continuous macropores that roots can follow.

Deep-burrowing species of dung beetles can create vertical channels extending over a meter into the soil, helping alleviate subsoil compaction. They can also

* Bury livestock dung beneath the surface.

* Create tunnels that increase infiltration and aeration.

* Transport organic matter into compacted soil.

* Reduce surface sealing caused by trampling and manure accumulation.

Pastures with healthy dung beetle populations often show improved water infiltration and reduced runoff.

2. Ants

* Excavate large amounts of soil.

* Create networks of tunnels and chambers.

* Increase soil porosity.

* Move nutrients and organic matter through the profile.

In some grassland ecosystems, ant activity can rival earthworms in soil mixing.

3. Other soil arthropods

* Springtail

* Mite

* Millipede

These smaller invertebrates generally do not directly break severe compaction, but they:

* Fragment plant residues.

* Stimulate microbial activity.

* Help form and maintain soil aggregates.

* Support the food web that sustains larger soil engineers such as earthworms.

How they reduce compaction over time

The process typically looks like this:

1. Organic matter is added (plant roots, litter, dung).

2. Invertebrates consume and redistribute it.

3. Burrowing creates pore networks.

4. Casts, faeces, and microbial activity form stable aggregates.

5. Soil develops better structure and resists future compaction.

6. Roots penetrate more easily and further reinforce the soil.

In pasture systems, a healthy pasture often relies on a partnership between:

* Earthworms

* Dung beetles

* Plant roots

* Soil microbes