Subgroup | Series name | Percentage | WRB 2006 link |
---|---|---|---|
8.13 | FLADBURY | 65% | Clayic Fluvic Eutric Gleysols |
8.11 | CONWAY | 15% | Fluvic Eutric Gleysols |
8.11 | ENBORNE | 10% | Fluvic Eutric Gleysols |
20 |
Loamy and clayey floodplain soils with naturally high groundwater |
Clayey alluvial soils on river floodplains dominate this association which occurs mainly in the South East and Northern England, but only locally in Eastern England. Fladbury series , grey clayey pelo-alluvial gley soils, usually cover two-thirds of the ground and subsidiary silty or loamy soils the remainder, often where tributaries join the main valley. Thus, the fine silty Conway series , which belongs to the typical alluvial gley soils, is a frequent associate, and similar but fine loamy Enborne soils occur in places. In the Mar Dyke catchment of south Essex, there are few soils other than Fladbury series, and in the Colne valley near Colchester, fine silty gleyic brown alluvial soils belonging to the Clwyd series are included. Near the Grand Union Canal, south of Rickmansworth, where the alluvium rests on gravel, clayey soils with gravelly subsurface layers are locally common.
The association occurs principally in the Vales of York and Pickering, but is also in Cleveland and along the middle and lower reaches of the rivers Wansbeck, Tees, Skerne, Swale, Wharfe, Ribble and Rawthey. It includes soils previously mapped as the Crimple series in North and West Yorkshire.
The association is widespread in South East England where the rivers drain clayey country rocks. It occurs along the middle reaches of the Darent, Eden, Medway and Stour. Adventurers' soils are present in the Naccolt valley, a tributary of the Great Stour south of Wye. Fine silty Clwyd soils are locally common along the Teise and Beult. In East Sussex along the upper reaches of the Rother and Ouse, there are small areas in the Tillingham and Cuckmere valleys and in Combe Haven between Bexhill and St Leonards, where clayey alluvium overlies peat at the floodplain margins giving Midelney soils. In West Sussex it is present in the upper catchments of the Adur, Arun and Rother.
In the lower reaches of the Meon and Hamble rivers in Hampshire, and the Yar on the Isle of Wight, humose topped soils and clayey over peaty Midelney soils are more important components than usual, and peaty Adventurers' soils are dominant locally. The Loddon, Wey and Mole, south bank tributaries of the Thames, drain Tertiary beds of mixed lithology, so here the ancillary soils are more varied than usual. Silty Conway soils are mostly absent, but coarse loamy Eversley , and loamy ferruginous Blackwater soils are included in the Loddon catchment, and fine loamy Enborne soils are locally dominant in stretches of the Wey especially where joined by tributaries. Stixwould and similar clayey over gravelly soils are common near Guildford.
The principal soils are affected by high groundwater and are waterlogged for long periods in winter (Wetness Class IV). Fladbury soils are often slowly permeable, even within 40 cm depth, whereas Conway and Enborne soils are moderately permeable. Winter flooding is common, but when protected by embankments and improved by field drainage measures the soils are only seasonally waterlogged (Wetness Class III) in the dry south-east of the region. The soils have large reserves of available water.
Winter cereals and oilseed rape are grown where adequate standards of arterial and field drainage are maintained in the Mar Dyke catchment near Bulphan and locally near Colchester. There is a restricted period during autumn when the heavy soils can be cultivated without risk of damage, but, because the return to field capacity is late, direct drilled crops of winter cereals are successful. Near Rickmansworth, where the field capacity period is longer, and downstream from Colchester where water-table control is poor, the land is mostly under grass. Because of appreciable poaching risk and winter flooding, use is confined to summer grazing.
In the North and South East the land is mainly in permanent grass because of high groundwater levels and flood risk. Large reserves of available water, often supplemented in spring by additional moisture from groundwater sources, ensure plenty of grass early in the growing season but droughtiness may limit yield later in the summer. Droughtiness is accentuated in dry years in South and West Yorkshire where soil moisture deficits are larger, but in the wetter districts of Cleveland and Northumberland grass yields are less frequently limited by drought. The clayey Fladbury topsoils have a large retained water capacity and there is an appreciable poaching risk which shortens the grazing period; flooding further curtails winter grazing. In the very wet catchments west of the Pennines, poaching risk is so severe that extensive stock rearing is the only practicable agricultural use. Where arterial drainage systems and climate allow, some arable crops, chiefly cereals, are grown. Spring sowing is preferred where there is still risk of winter flooding. However, first cultivations are performed in autumn when the land is still workable. Most land is too wet for satisfactory direct drilling of cereals.
Fladbury soils have little phosphorus but potassium levels tend to be high and magnesium levels moderate. Occasional liming is necessary, but there is a risk of manganese deficiency in cereals and grass if the soils are over-limed.
Tracts of unimproved meadow, fen and alder carr are of interest to naturalists. In the wettest sites great pond sedge (Carex riparia) and marsh marigold (Caltha palustris) are common and rare species such as the Loddon lily (Leucojum aestivum) and snakeshead fritillary (Fritillaria meleagris) occur locally. Stodmarsh National Nature Reserve is a good example of a southern eutrophic valley mire with periodically flooded meadows and reed beds. Newark Priory Marsh includes species such as square-stemmed St John's wort (Hypericum tetrapterum), water plantain (Alisma plantago-aquatica), reed-grass (Phalaris arundinacea) and arrow-head (Sagittaria sagittifolia). Titchfield Haven has calcareous fen and fen meadow, brackish marsh and saltmarsh.
Note that the yellow shading represents a buffer to highlight the location of very small areas of the association.
Northern Region
Midlands
Eastern Region
Northern Region
South Eastern 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 09/12/2024
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