Soil Associations

0831a YEOLLANDPARK

Soil and site characteristics

Fine loamy permeable soils variably affected by groundwater. Some slowly permeable seasonally waterlogged clayey soils.

Geology

Palaeozoic slaty mudstone and siltstone

Cropping and Land Use

Dairying on permanent and short term grassland; deciduous woodland.

Component soil series

Subgroup	Series name	Percentage	WRB 2006 link
8.31	YEOLLANDPARK	45%	Endoskeletic Mollic Gleysols
8.31	WIGTON MOOR	15%	Mollic Gleysols
5.43	IVYBRIDGE	15%	Eutric Endogleyic Endoskeletic Cambisols
7.12	TEDBURN	10%	Clayic Eutric Stagnosols

Covers 70 km² in England and Wales

Soilscapes Classification

22	Loamy soils with naturally high groundwater

0831a YEOLLANDPARK

Detailed Description

Yeollandpark association consists mainly of loamy groundwater gley soils with brown earths and some clayey surface-water gley soils overlying slaty, Devonian and Carboniferous rocks. It occurs in Devon and Cornwall in broad depressions and valley bottoms where it includes some alluvial soils, and below springs and flushes on hillsides. The main soils are fine loamy typical cambic gley soils of the Yeollandpark series which are grey mottled permeable clay loarns becoming very stony within moderate depth. The other soils include the deeper Wigton Moor series, fine loamy gleyic brown earths of the Ivybridge series and clayey pelo-stagnogley soils of the Tedburn series. In the valley bottoms there are commonly Conway, Kettlebottom and and Freni soils.

The association occupies wet ground in a landscape dominated by well drained soils; fields are often rushy and interspersed with patches of oakwood. Much of the Devonian slate outcrop in south Devon and along the south coast of Cornwall is well-dissected with steep sided valleys and intervening convex ridges. Here Yeollandpark soils are restricted to the bottoms of narrow valleys where they are associated with alluvial soils belonging to Camel and Kettlebottom series. In less dissected country, as around Newquay and Wadebridge, larger areas of Yeollandpark occupy broad shallow depressions, in which clayey Tedburn soils are more common. The occurrence of this association in flush sites on hill slopes, is well seen in the distinctive belt of wet ground in south Devon which runs east from Modbury towards Halwell. Better drained soils of the Ivybridge series tend to occupy the margins of basins and minor convexities. There are patches of Yeollandpark soils on slaty Carboniferous rocks in north Cornwall and west Devon.

Soil Water Regime

Most of the soils are affected by groundwater though this has been lowered by drainage in some places; Yeollandpark and Wigton Moor soils are seasonally waterlogged (Wetness Class III) and Ivybridge soils are somewhat drier (Wetness Class II).

Cropping and Land Use

Arable cropping is generally precluded by the unfavourable climate even where the soils are drained, except in west Cornwall where there are the advantages of earliness and a long growing season. Autumn cultivation is preferable as the soils are usually too wet for spring working. Permanent grassland is the best use for these soils as grass continues to grow in dry summer months when growth is checked on adjacent drier soils, though autumn poaching is a risk. In most years, the autumn rains re-wet the soils long before grass growth stops, causing an autumn flush of growth which overlaps the field capacity period by as much as 60 days, during which the sward and topsoil structure are likely to be damaged by stock and traffic.

0831a YEOLLANDPARK

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

South Western Region

Typical Landscapes

South Western 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 19/04/2024