All information Copyright, Cranfield University © 2018

Citation: To use information from this web resource in your work, please cite this as follows:
Cranfield University 2018. The Soils Guide. Available: www.landis.org.uk. Cranfield University, UK. Last accessed 24/06/2018

0561c ALUN

« 1022b ALTCAR 2 Associations Soilsguide Home 0343h ANDOVER 1 »

Soil and site characteristics

Deep stoneless permeable coarse loamy soils. Some fine loamy soils variably affected by groundwater, over gravel in places. Flat land. Risk of flooding.

Geology

River alluvium

Cropping and Land Use

Dairying and stock rearing on permanent and short term grassland; some arable crops where flood risk low.

Component soil series

Subgroup Series name Percentage WRB 2006 link
5.61 ALUN 50% Eutric Fluvic Cambisols
8.11 ENBORNE 15% Fluvic Eutric Gleysols
5.62 TRENT 15% Eutric Fluvic Endogleyic Cambisols

Covers 349 km2 in England and Wales

Soilscapes Classification

12
Freely draining floodplain soils

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0561c ALUN

Detailed Description

The Alun association consists of coarse and fine loamy brown alluvial soils. It is widespread in Northern England and occurs in the Midlands, south Wales and Devon. The Alun series (Wright 1980), coarse loamy typical brown alluvial soils, occupies two thirds of the association, commonly on the flatter parts next to the river. A typical profile has a brown to dark brown sandy loam topsoil which merges into a yellowish brown or brown sandy loam subsoil. The fine loamy Enborne, typical alluvial gley soils, and Trent series, gleyic brown alluvial soils, are found in slight hollows and abandoned meander channels.

The association covers 44 km² mainly in Lancashire but also in Derbyshire, Cheshire and Worcestershire. In Lancashire it is extensive on the floodplain of the Ribble, downstream from Bolton-by-Bowland. It also occurs in the Lune valley. Alun soils dominate on the floodplain in Goyt valley below Marple to its confluence with the Mersey, being bounded in many places by sandstone cliffs. The association has been mapped along the Manchester Ship Canal at Barton where it follows the former valley of the Irwell. Where the Severn crosses Carboniferous and Triassic sandstones between Bewdley and Stourport-on-Severn its alluvium is dominantly coarse loamy. In Derbyshire the association is on two tracts of Derwent alluvium, near Hathersage and Darley Dale, and on the Wye floodplain from Rowsley to Bakewell. The Wye alluvium is almost entirely calcareous and is dominated by Usher and similar soils. Many of the rivers have low terraces that are barely distinguishable from the floodplain. In such places Wick soils are included in the Alun association because of the scale of mapping. Shallow alluvial soils belonging to the Tavy series, with gravel below 50 cm depth, occur along the river Derwent. In Wales it is mapped over 40 km² mainly in narrow valleys draining the Carboniferous sandstone uplands. There is also a small area on the Cothi at Llansawel. I n many places there are coarse loamy Tavy and sandy Aled soils with gravel at less than 80 cm.

In Devon it is mapped over 18 km² along the rivers draining the Dartmoor granite, the Yealm, Tavy, Erme, Avon and Teign, in the wider parts of their valleys. The Alun, Tavy and Teign series are more common on levees and other sites close to the river channel. Wetter soils occupy backland strips.

The association covers 167 km² in Northern England. Many of the rivers have low terraces that are barely distinguishable from the floodplain. In such places there are Wick soils, necessarily included in the Alun association because of limitations of the scale of mapping. Shallow alluvial soils with gravel below 50 cm depth, belonging to the Tavy series, occur along the rivers Esk (north Cumbria), Eden, Till, Tweed and Wear. Wetter Enborne, Trent and, very occasionally, Fladbury (§ 36) soils are associated with hollows and old meander channels in the floodplain but are limited in extent.


Soil Water Regime

Alun soils are well drained (Wetness Class I) but Trent and Enborne soils (Wetness Class III and IV) are affected by groundwater. Flooding occurs in places and can affect long-term management.

Cropping and Land Use

The soils are easily worked but most land is under grass because of climate or risk of flooding. There is little poaching risk and the land is accessible throughout the year, except in wet hollows and immediately after heavy rain. Summer drought rarely checks growth severely and hence good yields are possible.

In the North of England good yields are possible for a wide range of crops including horticulture on the more sheltered sites. In some places the large proportion of silt and fine sand can lead to structural instability but if cultivation is avoided during wet periods or following heavy rain the damage is minimal. The soils are suited to both autumn and spring cultivations. Ley grass is included in rotations since most of the farms are predominantly dairy or beef enterprises.

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0561c ALUN

Typical Landscapes

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All information Copyright, Cranfield University © 2018

Citation: To use information from this web resource in your work, please cite this as follows:
Cranfield University 2018. The Soils Guide. Available: www.landis.org.uk. Cranfield University, UK. Last accessed 24/06/2018