How to Rewild

Neutral Grassland

Habitat Management Plan

HomeGuides

Neutral Grassland
Habitat Guide

Contents

Neutral Grasslands have moderate levels of biodiversity, but high levels of bioabundance compared with other grassland habitats, and they are typically found in lowland areas, (though upland habitat does exist). They’re often described as hay meadows, or ‘mesotrophic grasslands’, and they fall between Acid and Calcareous Grasslands in their soil pH, at about 5.5 to 6.5.

Usually growing on rich sediment laid down by rivers, or estuaries, the grass here is lush and dense. It’s ideal for grazing and hay production, but this means much of the habitat has been lost due to conversion for pasture. Today, Neutral Grasslands are mown seasonally for hay, and often grazed, too, but in the ancient past, they would have purely been grazed by animals like aurochs (large cattle) and wild horses.

Sub Habitats

Grassland with a pH between 5.5 and 6.5 below 300m in elevation and a characteristic mix of plant species. These habitats are typically managed by a mix of grazing and hay cutting and may be seasonally-flooded.

Grassland with a pH between 5.5 and 6.5 above 300m in elevation and a characteristic mix of plant species. These habitats are typically managed by a mix of grazing and hay cutting.

A neutral grassland which is typically cut rather than grazed, and does not meet the strict species criteria (see the UKHab website) for one of the above habitats.

Value

The nutrient-rich clay or alluvial soils don’t create the same competition for scarce resources that leads to wildflower diversity in Calcareous Grassland. Instead, this habitat is typically dominated by a few wildflower species, like ox-eye daisies, buttercups and clover. However, it is possible to find pristine Neutral Grassland habitat with very high plant diversity in some isolated parts of the country. These areas may also be home to orchid species and the rare fritillary which, though introduced, is a useful indicator species for a healthy habitat.

While plant diversity is usually modest, the number and density of flowers creates a rich resource for invertebrates, if the habitat is managed effectively. This strong base to the food web makes the habitat of high value to biodiversity, as it can support a huge number of foraging birds, mammals and amphibians. Many bird species thrive here, including threatened farmland species and ground-nesting waders. While the soils are too wet for most reptiles except grass snakes, amphibians benefit from this moisture, and the presence of ponds, ditches and streams set in a grassland habitat.

Sheep pasture
Agricultural intensification has caused species-rich Neutral Grassland to become Modified Grassland in many areas of pasture

Protect

Neutral Grassland used to be much more common, but the suitability of this habitat for conversion to rich pasture means very little is left in Britain. What remains is often degraded, due to a history of poor management or drainage of the local area. Where it has been lost completely, the habitat may have been enriched with fertiliser, ploughed over, or abandoned due to scrub encroachment, which happens rapidly on the rich soils.

The main threats to this habitat are drainage, and inappropriate management due to the absence of grazing. Scrub encroachment typically happens when livestock are removed – though some amount of scrub is very beneficial, creating a structurally-diverse habitat. When managing Neutral Grassland, be aware that overgrazing can cause ‘poaching’ of soils, especially during wetter months.

Cattle and horses are usually a better option than sheep here, or horses alone as they browse less selectively, creating a more diverse sward which isn’t overwhelmed by ‘horse weeds’ like dock. Their hooves and activity create bare patches and tussocks which are ideal spots for wildflower seeds to germinate. Pigs are ideal at low density, particularly in semi-wooded areas, as they create wallows, which are breeding habitat for amphibians and invertebrates.

Removing grazers altogether will degrade the habitat, as they maintain a variable sward height, which is essential for much of the community (plant, invertebrate, bird and reptile) dependent on this unique habitat. Fertilisers will increase the dominance and density of grass, and the sward height, turning this habitat into low value Modified Grassland. Grazing at moderate density is more suitable than mowing, and typically takes place from late September to December – or from June if the site is not mown – at a low-enough stocking density that the sward height stays above 5cm.

If you are forced to rely on mowing alone, a single annual cut may not be enough to maintain this habitat due to the vigour of grasses. The first cut is taken from late July to late September, depending on the latitude and climate. Some recommend a second cut in October, while others suggest another in February or early Spring (2 or 3 cuts maximum). Bear in mind that Spring cuts could be dangerous for ground-nesting birds, and the sward height should not drop below 5cm. More regular mowing (3 or more cuts) will lead to more vigorous grass growth, reducing the abundance of wildflowers. Cut grasses should be raked off, and used offsite as hay, to avoid a build-up of nutrients and smothering wildflower growth.

Neutral Grassland
In the lowlands, these habitats are often seasonally-flooded, leading to the presence of damp-ground species like Meadowsweet.

Restore

Neutral Grassland may have reverted to Modified Grassland if fertiliser has been added over time. This will have created a lush, tall sward that is likely to become overgrown with agricultural weeds like thistles, dock and nettles when mowing or grazing ceases. Restoring Modified Grassland back to Neutral Grassland is possible, and the method depends on the extent of modification.

All of these methods involve knocking back vigorous grass growth, as grass outcompetes wildflowers. Grass typically grows faster on ground with high levels of fertiliser. Fertiliser contains multiple nutrients – nitrogen (N), phosphorus (P) and potassium (K); to get back to a diverse grassland habitat, we’ll either reduce their concentration or make it harder for plants to access them.

1 – Removing Inputs

Artificially high levels of nutrients in the soil will naturally decline over time, as they wash out and are taken up and ‘locked away’ in plants. That’s why farmers must re-apply fertiliser every year. So, one of the first things to tackle is removing any artificial inputs. This includes supplementary feeding of livestock (e.g. grain troughs) and runoff from neighbouring farms. By avoiding fertilisers/muck-spreading, stopping supplementary feeding, and preventing incoming runoff, you should see a slow decline in soil nutrients. However, it is possible that there may still be another input which hasn’t yet been identified, like high atmospheric deposition, enriched floodwater, or even dog excrement! Bear in mind that Neutral Grassland already has a high baseline nutrient level, so lush growth is to be expected here.

2 – Sowing Hemiparasitic Plants

These plants attach to the roots of grass and suck nutrients out directly, reducing the vigour of the grasses. But these short plants do poorly in habitats with a tall sward, as they only thrive when they can get enough light. So, managing the habitat with grazers and/or mowing strategically, to avoid chopping them before they set seed, is necessary for successful establishment. They also need bare soil to germinate, so scarifying the grass before scattering seed gives them a good head start. Yellow Rattle is an example of a hemiparasitic plant which thrives in neutral soil.

3 – Grazing

In general, grazing your land with livestock should reduce nutrient levels over time, for a few different reasons. The animals will excrete nutrients into the soil, where they are washed away, and nutrients are released as volatile compounds into the air; they’re removed in animal products like wool and milk; and also in their meat. The overall impact varies a lot depending on the livestock, site, soils, climate etc. This method is slow but steady, and creates biodiversity along the way, as the grassland will be more varied in height than if you use a mower. Grazing also has the added benefit that it ‘masks’ the effects of nutrient-enrichment – livestock prefer eating taller, dominant plants like grasses, allowing shorter wildflowers to get established, provided that the area isn’t overgrazed.

4 – Mowing

Over a decade or two, you’ll find that consistent cutting and removal of hay should reduce the available nutrients in the soil and create a more diverse grassland community. However, in the short term, frequent mowing can create more vigorous grass growth, especially if the ground is rich in nutrients. Mowing can also remove plant seed heads before they have a chance to scatter onto the soil. It’s a balancing act, finding the right timing and frequency – twice a year is typically recommended for nutrient-enriched sites. The hay must be removed each time, to prevent a steady build-up of nutrients and choking-out fresh growth.

5 – Rooting

Fertilised grasslands, and those which have been intensively grazed or mown for a long time are very resistant to change. The sward will have become dense and matted, and it will take many decades to ‘reset’ this habitat. We can help this process along by introducing pigs, which turn over the turf in patches, just like our native Wild Boar. This knocks back the grass and allows seeds below the soil to germinate – it is likely to lead to a flush of agricultural ‘weeds’ at first. These will add structure and biodiversity, and are eventually succeeded (with regular grazing/mowing) by a more diverse collection of wildflowers and grasses. Without pigs, we can have a similar, though slightly less effective impact, using a rotavator. Note that this process – with or without pigs – leaves the grassland tussocky and uneven – it’s great for biodiversity, but not for recreation.

6 – Soil Stripping

Nutrients are concentrated in plants and the topsoil, so we can strip off this top layer of turf to solve the problem. With deep alluvial soils here, soil stripping may be easy to achieve, but a high water table could lead to waterlogging of stripped areas. And even if it is achieved, this will have a significant medium term carbon footprint, and will likely lead to runoff, soil compaction and loss of plant diversity. Removing strips of soil in rotation, will allow plant seeds and the soil community to transfer slowly from healthy grassland to recovering bare ground. While this method is very destructive, it is the only proven system for significantly reducing nutrients in one shot.

Aftercare

If you’re restoring Neutral Grassland from Modified Grassland, you’ll also want to restore the unique plant community. Native wildflowers may return naturally from the seedbank in the soil if the habitat has only recently become degraded, but if this doesn’t happen, then green haying is also an option. This involves taking a cut of a healthy Neutral Grassland meadow nearby and spreading the arisings on your land to transfer the seed. Bear in mind that this will only spread plants which have seed heads at the time of the cut.

Wildflower seed mixes for Neutral Grassland may include the hemiparasite Yellow Rattle, which may aid in wildflower establishment and reduce grass vigour. Habitat Aid and Emorsgate Seeds offer locally-sourced mixes of meadow seeds which are appropriate for your soils, that are typically sown on scarified grassland.

Contents