All terms


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A horizon

The mineral horizon at or near the surface in which an accumulation of humified organic matter is mixed with the mineral material. Also, any ploughed or disturbed surface layer.


Uptake of matter or energy by a substance.

Accelerated erosion

The erosion that exceeds the normal geologic erosion and becomes destructive. It occurs when people disturb the soil or the natural vegetation by cutting forests, overgrazing, ploughing hillsides, recreational activity (e.g., ATV vehicle uses), indiscriminate (arbitrary) burning, or construction of roads and buildings.


The process in which the concentration of hydrogen ions in the soil gradually increases, caused by removal of (slightly alkaline) crop produce, leaching and the use of acidifying N fertilizer types, accelerated or insufficiently compensated by the natural constituents of a soil among which the parent material.


A large group of bacteria that grow in long filaments that are too small to see without magnification. Actinomycetes generate the smell of


The proces in which (agricultural) management measures are taken up by practitioners.


Process by which atoms, molecules or ions are retained on the surfaces of solids by chemical or physical bonding.

Aerated soil

An aerated soil is a soil with a good movement of air through the soil structure. The opposite is a wet waterlogged soil, where the soil pores are filled with water.


With oxygen. Aerobic organisms, including animals and most soil organisms, require environments with oxygen. See anaerobic.


Soil aggregate consisting of two or more soil particles bound together by various forces.

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