Soil Associations

0611c MANOD

Soil and site characteristics

Well drained fine loamy or fine silty soils over rock. Shallow soils in places. Bare rock locally. Steep slopes common.

Geology

Palaeozoic slate, mudstone and siltstone

Cropping and Land Use

Stock rearing and woodland in uplands; some dairying and cereals in Devon and Cornwall with woodland on slopes.

Component soil series

Subgroup	Series name	Percentage	WRB 2006 link
6.11	MANOD	50%	Chromic Mollic Endoskeletic Umbrisols
5.41	DENBIGH	20%	Eutric Endoleptic Cambisols
3.13	POWYS	10%	Umbric Leptosols

Covers 5372 km² in England and Wales

Soilscapes Classification

13	Freely draining acid loamy soils over rock

0611c MANOD

Detailed Description

The Manod association consists mainly of free draining fine loamy soils over Palaeozoic mudstone, siltstone or slate. It is widespread in Wales and occurs in Northern and South West England and the Midlands. Most of the land is above 200 m O.D. with more than 1000 mm annual rainfall. Although some is level or gently sloping, much is steeper than 11 degrees. In the wetter western districts or where the rocks are particularly hard the association reaches almost to sea level as in the Conwy valley and on the west coast of Wales. Typical brown podzolic soils, mainly Manod series, predominate and typical brown earths such as the Denbigh series occupy a fifth of the land. The Powys soils, loamy rankers, are locally common where bedrock is close to the surface. The Manod series has solid or shattered rock within 80 cm depth and is a permeable clay loam with dark topsoil over ochreous subsoil, usually with granular structure. Denbigh series differs in having a brownish subsoil with blocky structure; it usually occurs on gentler slopes and is more common on farmland. Powys soils, with solid or broken rock within 30 cm depth are most frequent in hilly country, on knolls and ridges or on slopes eroded by cultivation or solifluction.

In the Welsh Borderland because there is a larger proportion of siltstones than elsewhere, many soils are fine silty and Denbigh soils are replaced by Barton series. Withnell soils are common where sandstone forms the bedrock. Many of the deep narrow valleys contain narrow strips of alluvium and river terrace deposits. In Wales fine silty Barton soils and fine silty brown podzolic soils similar to Manod series are more common than elsewhere. The fine loamy Meline series is a deeper soil in drift while the coarse loamy Withnell series occurs on occasional sandstone bands. Many soils on slopes too steep or rocky to cultivate often have a thick surface mat of roots and plant remains. On the higher slopes Parc soilsare found. Steep upland slopes often carry very stony profiles of the Banc series. In localized wet spots over drift there are some stagnogleyic brown earths and cambic stagnogley soils. On high ground recently reclaimed from moorland, stagnopodzols and stagnohumic gley soils also appear. Locally there are small areas of crystalline rocks. These give other minor component series such as Moretonhampstead series in Snowdonia, and Gunnislake and Trusham series in south-west Dyfed. Also included is a narrow fringe of reddish soils in drift from Carboniferous Basement Beds below the Eglwyseg rocks near Llangollen. Many of the valleys traversing the association are floored with strips of alluvium and discontinuous river terraces.

In the South West, Manod association overlies Devonian and Carboniferous rocks, on steep land at low altitudes and on high moorland margins with more variable slopes, and was formerly mapped as Dartington series. It occurs also on the metamorphic aureoles of the granite masses of Devon and Cornwall. In Devon some soils over Carboniferous sandstone are included, Loxhoreand Neath series. Red rocks in the Quantock Hills give inclusions of Whitcottand Milford soils. Small patches of wetter land on the moorland fringe include stagnogley soils, Sportsmans series, cambic gley soils, Yeollandpark series, and stagnopodzols represented by Hafren and Hiraethog series. Unlike other regions, rock outcrops are rarely encountered.

In Northern England the association is common in the Lake District and includes small amounts of the coarse loamy Moretonhampsteaa series. Near Penrith, there are Withnell soils in drift derived from a Palaeozoic conglomerate. Similar soils occur at the foot of the Cross Fell escarpment.

Soil Water Regime

The main soils are permeable and well drained (Wetness Class I) but because of the climate, the soils remain moist throughout most years. Where average annual rainfall exceeds 1100 mm there is little or no drought restriction to grass growth on Manod and Denbigh soils. Grass on shallow very stony soils such as the Powys series can, however, suffer from drought. The soils readily absorb excess winter rainwater except on steep land or where bedrock is near the surface.

Cropping and Land Use

Most of the land is in permanent grass, leys or grazing. There is very little arable cropping but cereals are grown locally on gentle slopes, usually at low altitudes, and brassica and root crops are sometimes grown for feeding sheep and cattle. The land is well suited for producing hay and silage where slopes are not too steep. The growing season is about 7.5 months (Smith 1976) and in good years there are over 5 months available for grazing without risk of damage to the sward or soil structure. The soils are naturally acid and phosphate deficient, but when adequately limed and fertilized grass grows well. Where grazing pressure is light, as on steep slopes marginal to moorland, the bent-fescue sward is infested with bracken and gorse. Care is needed to prevent erosion when cultivating or otherwise improving steeply sloping land. Where slopes are gentle, Manod and Denbigh soils are useful for dispersing slurry (Lea 1979), which is often spread prior to cultivation.

In Wales and the North much of the land was forested before enclosure and some steep land has reverted to scrub woodland. Old oak woods and coniferous forests are widespread where agriculture is restricted by steep slopes. Woodlands occupy about one-fifth of the land, often in sheltered valleys. Sitka spruce is commonly planted and yields very well. Douglas fir is also productive in sheltered sites. Larch is often grown but yields are somewhat smaller. Grand fir and Western hemlock are suitable amenity species in the valleys. There is little risk of windthrow except where the soils are shallow and the site exposed. Many of the older deciduous woodlands are highly valued for recreation and as wildlife habitats.

0611c MANOD

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

Midlands

Wales

Northern Region

Typical Landscapes

South Western Region

South Western Region

South Western Region

Wales

Wales

Wales

Wales

Wales

Wales

Wales

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 10/10/2024