Irish Plaggen Soils—their Distribution, Origin, and Properties

Abstract

Soils have been described in Ireland which meet the definition of thick manmade surface horizons conforming to Plaggen epipedons (Conry, 1969). Unlike the north-west European Plaggen soils these Irish Plaggen soils have not been formed by the prolonged addition of Plaggen material (heather sods, forest litter, or grass plaggen) and dung, but were formed by the addition of calcareous sea sand, applied either alone or mixed with stable dung. Although only small quantities of grass sods were used in the formation of the Irish Plaggen soils, they should not be separated genetically from the true Plaggen soils of NW. Europe. They occur in coastal areas, within one mile of the coast approximately, where sources of calcareous sand are readily available.These Plaggen soils generally have a loamy-coarse-sand to coarse-sandy-loam texture, a granular to single grain structure and loose to very friable consistence. Colour is directly related to the colour of the original soil. Depth varies from field to field and is related to population density.The Irish Plaggen soils are always base saturated. Phosphorus, potassium, magnesium, and sodium are very much higher than in the unsanded counterpart.Trace element deficiencies include boron, magnanese, and cobalt. Like the Plaggen soils of NW. Europe the Plaggen soils in Ireland are superior in productivity to their non-Plaggen counterparts ; not only has man's influence increased crop yield substantially, but the range of crops produced has also been enlarged. The Irish Plaggen soils show symptoms of a moisture deficit only in prolonged dry periods.

Multi-Element Analysis of Soils from Scottish Historical Sites. Interpreting Land-Use History Through the Physical and Geochemical Analysis of Soil

“…The genesis of such thick topsoils at Greaulin, largely associated with the kailyards, possibly reflects the inevitable build-up of material given the use of such areas for the storage of manure and general occupation debris, such as discarded and used building materials like turf and thatch. The use of additives such as turf and peat as fertilizer would also increase on-site topsoil depths relative to the off-site soils, and numerous studies have suggested a link between the anthropogenic additions of such materials and the occurrence of deep topsoils and farm mounds (Pape, 1970;Conry, 1971;de Bakker, 1980;Simpson, 1985).…”

“…According to the classification system of the Soil Survey of England and Wales (Avery, 1973), soils with anthropogenically modified topsoils greater than 40 cm thick are referred to as ''man-made humus soils'', although such soils are often referred to as ''plaggen'' (e.g. Conry, 1971Conry, , 1974Staines, 1975;Van de Westerningh, 1988). The genesis of such thick topsoils at Greaulin, largely associated with the kailyards, possibly reflects the inevitable build-up of material given the use of such areas for the storage of manure and general occupation debris, such as discarded and used building materials like turf and thatch.…”

The formation of deep topsoils in Orkney

“…The brown soils developed by the same process except that grass sods were used. Conry (1971Conry ( , 1972 has investigated similar deep topsoils in southwest Ireland where, however, calcareous sand was one of the main additives. A similar process has also been observed by Staines (1979) for the Hayle area of Cornwall.…”

Micromorphological report of Hof ter Coign

“…Compared to natural soils, plaggen are rich in phosphates and animal dung, and might display traces of layering and horizontally-aligned plant remains due to the continuous deposition of material trampled by cattle -although these features can be easily obliterated by periodic tilling and cultivation. Plaggen soils can also present inclusions of peat turf, commonly used for bedding of cattle in order to soak up the animal wastes (Bryant and Davidson 1996), as well as household waste (Goldberg and Macphail 2006) or seaweed (Conry 1971).…”