Soil Associations

0721b ONECOTE

Soil and site characteristics

Slowly permeable seasonally waterlogged clayey and loamy upland soils with a peaty surface horizon often over soft rock. Soils very acid where not limed.

Geology

Carboniferous and Jurassic mudstone

Cropping and Land Use

Wet moorland habitats of poor and moderate grazing value; some dairying on improved ground; coniferous woodland.

Component soil series

Subgroup	Series name	Percentage	WRB 2006 link
7.21	ONECOTE	50%	Clayic Dystric Histic Stagnosols
7.21	WILCOCKS	30%	Umbric Stagnosols
7.21	IPSTONES	20%	Dystric Histic Albic Planosols

Covers 460 km² in England and Wales

Soilscapes Classification

19	Slowly permeable wet very acid upland soils with a peaty surface

0721b ONECOTE

Detailed Description

The Onecote association consists of loamy and clayey cambic stagnohumic gley soils, in particular the Onecote, Wilcocks and Ipstones series. It is mainly on gently to moderately sloping land between 180 and 600 m O.D., on shale or mudstone and thin local drift. It occurs in the North York Moors, the Pennines, Shropshire and Devon. The clayey Onecote series is developed in weathered clay shale or soft mudstone with virtually no drift contamination. In contrast the Ipstones series is loamy over clayey and the Wilcocks series entirely loamy. All these soils have slowly permeable subsoils and under the prevailing wet, cold climate, have developed a peaty or humose topsoil. In the Midlands, the association is developed exclusively on Carboniferous rocks and occurs only above 305 m O.D. It covers approximately 68 km² and is found mainly in north Staffordshire, east Cheshire, and on the Clee Hills in Shropshire. On the Staffordshire moors, Onecote soils predominate, with Wilcocks soils occurring mainly where the underlying bedrock contains thin sandstone bands which have been incorporated into the local drift, and Ipstones series where drift thins out over shales and mudstones. Rare profiles of the Revidge and Mynydd series are included, normally along ridges where thin hard bands outcrop, and occasional Hepste and Winter Hill soil are developed in peat on the highest ground. The Dale and Bardsey series are found where the predominantly acid parent material is locally base rich, or on lower ground where the climate is less severe. Elsewhere in north Staffordshire and Cheshire, Wilcocks soils are more common than the Onecote series, as the parent shales or mudstones are often covered by till. In Shropshire the association occurs on the upper slopes of the Clee Hills where the soils were originally mapped as Melville complex. Here the parent rocks contain more interbedded sandstones than in the Pennines and Wilcocks soils are often more common than the Onecote series. In addition, the soils have less well developed peaty or humose surface horizons and commonly grade into soils with only thin superficial layers of decaying plant material.

In Devon, about 10 km² have been mapped on the Culm Measures between South Molton and Tiverton and on the Hartland peninsula on some of the highest and wettest parts of the Carboniferous outcrop in the county, with an annual rainfall of around 1,300 mm. Wet heathland and Molinia moorland are still widespread in spite of reclamation for agriculture and forestry. Humose clay loam or silty clay loam topsoils predominate, being separated from the strongly mottled subsoil by a pale, little-mottled horizon. The clayey Onecote and loamy Wilcocks series are most common, Ipstones profiles being relatively rare. Soils with grey, non-humose surface horizons can be found, particularly in older enclosures, and include the Tedburn, Hallsworth, and Brickfield series. The Onecote association occupies shallow basins and some ridge crests, similar to those extensively occupied by the Hallsworth 2 association on the drier parts of the Culm outcrop, and shares a sinuous, often abrupt, boundary with the Neath association upslope on drier ground.

The greater part of the association occurs on Jurassic (Estuarine Series) rocks, in the North York Moors, and on Carboniferous rocks in Littondale, upper Wharfedale and Craven. The Onecote, and the Mynydd series, are developed in clay or soft mudstone where there is little or no drift. The Wilcocks and Ipstones series are common where Head, partly derived from adjacent sandstones and grits, masks the underlying mudstones. Raw peat soils are sometimes found, either the Winter Hill series on hilltops or the Floriston series on narrow valley floors. The Howe series commonly occurs at the margins of the association, on concave slopes below sandstone exposures. There are often podzolic soils, especially the Gelligaer series associated with Wilcocks series.

Soil Water Regime

Being in districts of high rainfall, the peaty surface horizon quickly becomes waterlogged and these slowly permeable soils are waterlogged for long periods during the growing season (Wetness Class V). They do not readily absorb winter rain so run-off can be rapid.

Cropping and Land Use

Because of the climatic limitations of high rainfall and short growing season, the association is unsuitable for arable crops and only marginally suited to grass. It is mainly under open moor, rough grazing or poor permanent pasture and most is used as grazing for sheep. In its unimproved state it often consists of heather, with hydrophilous species of low grazing value such as cross-leaved heath (Erica tetralix), cotton-grass (Eriophorum spp), deer-grass (Trichophorum cespitosum), rushes, especially heath rush (Juncus squarrosus), and mosses (Hypnum spp). Elsewhere it can be dominated by Molinia or Nardus with moderate grazing value. Enclosed grassland is commonly rush infested. Reclamation of moorland and rough grazing is sometimes possible by burning, rotavating and reseeding. The soils are strongly acid and poor in nutrients, requiring regular dressings of lime and fertilizer. Ploughing is not advisable because burying the peaty topsoil increases the risk of waterlogging at the surface and can cause rapid reversion to rough pasture. Soils with peaty topsoils less than about 20 cm thick can be improved by drainage but require close pipe spacing, or mole drainage with permeable fill over main drains. Soils with thicker peat are uneconomic to drain however and usually only have open ditches; such soils, or those where there is more than 1500 mm rainfall, are unsuited to reclamation. Improved grassland needs careful management as soils remain at field capacity for most of the year and their water retentive, organic-rich topsoils are very susceptible to poaching or damage by farm machinery. Reseeding is difficult unless soils are worked in midsummer and cultivations are possible only in dry years.

In the North York Moors and Yorkshire Dales National Parks there has been resistance to afforestation and moorland reclamation. Much of the land is used as grouse moor and water-gathering grounds but is not accessible to the public. Over-use of the Lyke Wake Walk footpath, in the North York Moors, has resulted in erosion. Sporadic uncontrolled fires have damaged the peat surface over wide areas.

0721b ONECOTE

Distribution Map

Note that the yellow shading represents a buffer to highlight the location of very small areas of the association.

Keys to component soil series

Midlands

Northern Region

Typical Landscapes

Midlands

Northern Region

Northern Region

Northern Region

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Citation: To use information from this web resource in your work, please cite this as follows:
Cranfield University 2024. The Soils Guide. Available: www.landis.org.uk. Cranfield University, UK. Last accessed 18/04/2024