Glossary | Scotland's soils

Acidic soil	Soil with a pH of less than 7.
Aeolian deposit	Material deposited by the wind.
Alluvial soils	Soils developed in recent river, estuary or marine deposits.
Alluvium	Material deposited by flowing water.
Available water capacity	In soil, the portion of water that can be readily absorbed by plant roots.

Basin peat	Poorly drained lowland soils with an organic surface layer at least 50 cm thick. Basin peat generally forms at low levels in distinct depressions.
Blanket peat	Poorly drained upland soil with an organic surface layer at least 50 cm thick. It is unconfined and "blankets" the landscape.
Brown soil	Moderately acid soils with brown mineral topsoils and brown or yellowish subsoils.
Bulk density	The weight of dry soil divided by its volume.

Calcareous soils	Relatively thick soils, rich in calcium carbonate.
Carbon	A chemical element with the symbol C. It is found in all known life.
Carbon dioxide	The most abundant greenhouse gas. It occurs naturally, but the concentration in the atmosphere has increased rapidly since the industrial revolution. Chemical formula is CO₂.
Citizen science	Scientific work carried out by the general public, often in collaboration with, or under the direction of, professional scientists and scientific institutions.
Clay	Clay particles are small particles of soil less than 2 micrometers in diameter. It is also the name of a soil texture.
Climate / climate change	Climate is the average weather taken over a long period of time - usually 30 years. Climate change is the change in this average.
Colluvium	Material which collects at the foot of a slope.
Compaction	When the soil particles move closer together as a result of the weight on top of them. The spaces between the soil particles decrease.
Complex	A map unit where soils occur in such a complicated pattern that it is impossible to divide them into individual soil types at the scale of the map survey.
Contamination	The addition of contaminants to the soil.
Cryogenic material	Material created by the action of freeze and thaw processes.
Cultivated	Soil prepared and used for growing plants.

Deficiency	Lacking in something important e.g. essential nutrients.
Diffuse pollution	Pollution caused by a number of often minor sources of potential pollutants coming together, resulting in environmental damage.

Ecosystem services	The benefits the environment produces for people, such as clean air, water, food and materials.
Ecosystems	All of the living things (plants, animals, organisms and people) in a given area that interact with each other and their wider environment.
Erosion	The movement of material by wind or water.

Fluvioglacial	Sediments deposited by meltwater from glaciers. Also termed "glaciofluvial".
Food security	When all people, at all times, have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences (FAO definition).

Glaciofluvial	Sediments deposited by meltwater from glaciers. Also termed "fluvioglacial".
Gleys	Soils that are periodically or permanently waterlogged. They are typically greyish with greenish or blueish tinges and often have a blotchy appearance.
Greenhouse gas (GHG)	A gas that traps heat.
Gully	A channel cut in the land by water removing the soil. Gullies can vary from 10 cm to more than 1 m deep.

Habitat	A particular environment in which specific plants and animals live, depending on the climate, geography, and what plants grow there.
Horizon	A distinct layer of soil which runs roughly parallel to the soil surface.

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Leaching	The loss of soluble materials from the soil, usually caused by water filtering through it.
Legislation	A law or set of laws suggested by a government and made official by a parliament.
Lithosols	Shallow soils with rock less than 10 cm from the surface.

Magnesian soils	Soils with a high magnesium content.
Map unit	The basic unit of a soil map. Soils are grouped into map units for display purposes. The map unit is a collection of areas defined and named in terms of their soil components or properties.
Moraine	Rocks and sediments transported by a glacier then left behind when the glacier melts often forming ridges or mounds.

National Soil Inventory of Scotland (NSIS) (1978 -1988)	The National Soil Inventory of Scotland dataset was collected between 1978 - 88 from locations aranged on a 10 km grid across the country.
Nitrogen	A chemical element with the symbol N. It is an essential nutrient for plant growth and protein building.
Nitrous oxide	A greenhouse gas nearly 300 times more powerful than carbon dioxide. It also reacts with oxone in the stratosphere contributing to thinning of the ozone layer. Chemical formula is N₂O.
Nutrients	Elements or compounds that are essential for all living things.

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Parent material	The material from which a soil is formed.
Peat	An accumulation of partially decomposed organic material, usually formed in waterlogged conditions. Peat soils have an organic layer at least 50 cm deep from the soil surface which has an organic matter content of more than 60 %.
Pedotransfer function	A function that uses information we have, for example soil properties measured from soil surveys, to estimate other soil properties that are more difficult or expensive to measure.
Podzols	Acid soils with a grey, leached layer just below the surface and bright orangey-brown coloured subsoils and / or dark brown to black organic rich subsoil.
Policy	A statement of intent - a set of ideas or required outcomes and guidance on how to achieve them.
Prime agricultural land	Land in Land Capability for Agriculture Classes 1, 2 and 3.1
Profile	A vertical section of the soil that show its horizons.

QMUNIT

The map unit of the National soil map of Scotland. The QMUNIT is a number identifying a unique combination of parent material, component soil types and associated landforms.

Raised beach	A former beach now lying above the shore line.
Rankers	Shallow soils more than 10 cm thick with rock near the surface.
Regosols	Well drained, poorly developed soils, often with a mineral topsoil and no distinct layering in the subsoil.
Rendzinas	shallow calcareous soils (rich in calcium carbonate) developed on limestone and more than 10 cm thick.

Saline	Soils with a high salt content from sea water.
Scree	An accumulation of loose stones or rocky debris lying on a slope or at the base of a cliff.
Semi-confined peat	Poorly drained, partly confined soils with an organic surface layer at least 50 cm thick. It is generally formed in valleys, on terraces or between ridges.
Series	A soil series is made up of soils with a similar type and arrangement of horizons (layers) which are developed on a similar parent material. The map unit of the Soil map of Scotland (partial cover).
Soil association	A grouping of soils developed on similar parent materials.
Soil biodiversity	The life within the soil.
Soil classification	The arrangement of soils into groups based on their key characteristics.
Soil functions	The benefits that soils provide, such as growing food, filtering water and storing carbon.
Soil organic carbon	The carbon derived from living and dead plants and animals. It is the principal component of soil organic matter.
Soil organic matter	Living and dead plant and animal material in soil.
Soil phase	A subdivision of soil series.
Soil sealing	The permanent covering of the soil surface with a water-tight material like concrete.
Soil structure	The arrangement of soil particles into larger aggregates or clumps.
Soil texture	The relative proportions of sand, silt and clay particles.

Thematic maps	Any map designed to show a specific theme or subject area
Till	Sediment deposited directly by glaciers usually containing a mixture of materials of different shapes and sizes; because of this is it sometimed called boulder clay.
Topsoil	The upper most layer of the soil.

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Water-modified till

A till that has been sorted by the movement of water after it has been deposited.

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