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Aeolian deposit Deposits which have been transported and laid down on the earth’s surface by the wind
Alluvium Loose, unconsolidated soil or sediments carried in suspension by rivers and subsequently deposited on floodplains
Aqua-regia digestion Aqua regia is a mixture of nitric and hydrochloric acids. It is extremely corrosive and has the ability to dissolve materials that are unaffected by the acids on their own. The name is derived from its ability to dissolve gold and some other noble metals. In soil science it is commonly used to extract elements from soil for analysis, although quartz and several other minerals are resistant to attack
Available water capacity In soil, the portion of water that can be readily absorbed by plant roots
Bulk density The dry weight of soil divided by its volume. Typically expressed in grams/cubic centimetre (g/cm3)
Calcareous Describes soils with free calcium carbonate within the profile
Clay Type of soil material or when used to describe texture of soil refers to the finer fraction of soil material (less than 2 µm in soils)
Colluvium General term for loose, unconsolidated material deposited at the base of slopes or on lower slopes by water action and/or by slow continuous gravitational creep
Cryogenic material Refers in this instance to soil parent materials where annual periods of freezing and thawing determine the characteristics of the parent material and soil forming processes
Ecosystem services A concept for identifying and quantifying the benefits that individuals and society can obtain from our natural ecosystems
Ecosystems Community of living organisms (plants, animals and microbes) in conjunction with the non-living components of their environment (things like air, water and mineral soil), interacting as a system
Fluvioglacial Material formed and deposited by the action of streams flowing from melting ice at the end of a glacier or at the edge of an ice-sheet
Gley Soils that develop under conditions of permanent or temporary waterlogging and exhibit poor natural drainage. Typically grey coloured with greenish or bluish tinges and often has a ‘blotchy’ appearance
Land capability for agriculture A system of land classification developed by the Macaulay Land Use Research Institute (now part of the James Hutton Institute) which classifies land according to the limitations imposed on it by physical and biological factors (climate, gradient, soil, wetness, erosion and vegetation) which affect agriculture. The land is ranked on the basis of its potential productivity, cropping flexibility and ease of management
Leaching The loss of mineral and organic solutes due to percolation from soil
Lithosol Shallow soils less than ten centimetres thick overlying rock
Magnesian Magnesian describes soils with a high magnesium content usually inherited from the parent rock
Moraine Unconsolidated debris or fragments of rock material brought down with the movement of a glacier. The deposits usually occur as a range of moundy or linear topographic features
NSIS1 National Soil Inventory of Scotland is a dataset of site, soil and analytical data collected between 1978 and 1988 from sites located on a regular 5 km grid across Scotland
Organic parent material Soil parent material comprising the remains of plant material which due to wetness or low temperatures or a combination of both, has accumulated, rather than being broken down by natural agencies and incorporated into the soil
Podzol Soils with a dark organic surface horizon overlying a grey, leached horizon and a brightly coloured, strong brown B horizon. Horizons are usually very distinct from each other
Prime agricultural land Currently defined in Scotland as land comprising Land Capability for Agriculture Classes 1, 2 and 3.1
Raised beach A former beach which has, by subsequent earth movement and a relative fall in sea-level, been raised above the current shore-line
Ranker Shallow soils that are more than ten centimetres thick overlying rock or scree. Poor horizon development
Representative soil profile pits Soil pits which are deemed to be typical of the soil in the area
Saline Saline describes soils with a high sodium content, inherited from sea water
Scree A mass of boulders and broken rocks of all sizes which accumulates on slopes usually of mountains, having been broken from the main rocks by weathering and rolled down under the action of gravity
Soil association A term used in Scotland which groups together different soils (soil series), developed on similar parent material, forming a characteristic soil pattern on the landscape. The soil association usually has the same name as its most common series
Soil classification Any systematic arrangement of soils into groups and categories, based on distinguishing profile characteristics and properties. Broad groupings are made on the basis of general characteristics and subdivisions on more detailed differences in specific properties
Soil complex A mapping unit used in Scotland where soils occur in such an intricate and recurring pattern on the landscape that delineation into individual soil series is not possible at the scale of the survey
Soil degradation A change or disturbance to the soil that is perceived as deleterious or undesirable
Soil functions The various roles soils perform in our every-day life, e.g. growing food and timber / Filtering and controls water flow / Storing carbon and exchanges gases with the air / providing important habitats which sustain many forms of life (biodiversity) / providing a medium which preserves archaeological remains and examples of our cultural heritage ./ providing raw materials such as sand / providing a platform for buildings, roads, dams and pipelines;
Soil horizon A recognisable layer of soil of relatively uniform material, which lies more or less parallel to the surface and has fairly distinctive soil properties
Soil map A map showing the distribution of soil types or other soil mapping units in relation to the prominent physical and cultural features of the earth’s surface
Soil organic carbon Soil organic carbon, the major component of soil organic matter essentially derived from residual plant and animal material, synthesised by microbes and decomposed under the influence of temperature, moisture and ambient soil conditions. Content can be calculated using concentration (%), bulk density and depth for the whole soil profile, a specific horizon or depth interval
Soil parent material The mineral or organic material from which the soil above is developed
Soil phase A mapping term used in Scotland where variations (e.g. thickness of topsoil, stone content,) in soil series are present and of sufficient extent and relevance to be mapped
Soil profile A section of soil showing the different horizons, or layers, extending downwards from the surface to the parent material
Soil quality The ability of the soil to carry out its functions
Soil sealing The permanent covering of the soil surface with an impermeable material
Soil series As defined by the Soil Survey of Scotland, soil series comprise soils with a similar type and arrangement of horizons which are developed on similar parent material
Thematic maps Any map designed to show a specific theme or subject area
Till Material and rocks dragged along the lower part of a glacier and left behind when the ice melts. The composition is very variable and depends on the rocks over which the glacier travelled. The deposits are poorly sorted consisting of sand, silt, clay, stones and boulders intermingled in any proportion and forming a layer rom less than 1 metre to over 100 m thick
Topsoil organic carbon content The concentration of organic carbon present in the surface horizon expressed as a percentage
Water-modified till A till deposit (see Till above) in which the parts of the till deposit has been re-sorted by water action after the ice has melted. The upper part of the till is noticeably altered in structure and in texture and is generally coarser and sandier than the unaltered till below
World Reference Base (WRB) An international standard taxonomic soil classification based mainly on field observable attributes within the soil horizons and a description of the kind and arrangements of the horizons