[The Cooperative Soil Survey] Soils Tutorial: Glossary

Glossary

Definitions from the Soil Science Society of America (SSSA)

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Taxadjuncts Soils that cannot be classified in a series recognized in the classification system. Such soils are named for a series they strongly resemble and are designated as taxadjuncts to that series because they differ in ways too small to be of consequence in interpreting their use and behavior.

Terrace An embankment, or ridge, constructed across sloping soils on the contour or at a slight angle to the contour. The terrace intercepts surface runoff so that water soaks into the soil or flows slowly to a prepared outlet.

Terrace(geologic) An old alluvial plain, ordinarily flat or undulating, bordering a river, a lake, or the sea.

Texture, soil The relative proportions of sand, silt, and clay particles in a mass of soil. The basic textural classes, in order of increasing proportion of fine particles, are sand, loamy sand, sandy loam, loam, silt loam, silt, sandy clay loam, clay loam, silty clay loam, sandy clay, silty clay, and clay. The sand, loamy sand, and sandy loam classes may be further divided by specifying "coarse", "fine", or "very fine."

Thin layer(in tables) Otherwise suitable soil material too thin for the specified use.

Till plain An extensive area of nearly level to undulating soils underlain by glacial till.

Tilth soil The physical condition of the soil as related to tillage, seedbed preparation, seedling emergence, and root penetration.

Toe slope The outermost inclined surface at the base of a hill, part of a foot slope.

Topsoil The upper part of the soil, which is the most favorable material for plant growth. It is ordinarily rich in organic matter and is used to topdress.roadbanks, lawns, and land affected by mining.

Trace elements Chemical elements, for example, zinc, cobalt, manganese, copper, and iron, are in soils in extremely small amounts. They are essential to plant growth.

Taxadjuncts	Soils that cannot be classified in a series recognized in the classification system. Such soils are named for a series they strongly resemble and are designated as taxadjuncts to that series because they differ in ways too small to be of consequence in interpreting their use and behavior.
Terrace	An embankment, or ridge, constructed across sloping soils on the contour or at a slight angle to the contour. The terrace intercepts surface runoff so that water soaks into the soil or flows slowly to a prepared outlet.
Terrace(geologic)	An old alluvial plain, ordinarily flat or undulating, bordering a river, a lake, or the sea.
Texture, soil	The relative proportions of sand, silt, and clay particles in a mass of soil. The basic textural classes, in order of increasing proportion of fine particles, are sand, loamy sand, sandy loam, loam, silt loam, silt, sandy clay loam, clay loam, silty clay loam, sandy clay, silty clay, and clay. The sand, loamy sand, and sandy loam classes may be further divided by specifying "coarse", "fine", or "very fine."
Thin layer(in tables)	Otherwise suitable soil material too thin for the specified use.
Till plain	An extensive area of nearly level to undulating soils underlain by glacial till.
Tilth soil	The physical condition of the soil as related to tillage, seedbed preparation, seedling emergence, and root penetration.
Toe slope	The outermost inclined surface at the base of a hill, part of a foot slope.
Topsoil	The upper part of the soil, which is the most favorable material for plant growth. It is ordinarily rich in organic matter and is used to topdress.roadbanks, lawns, and land affected by mining.
Trace elements	Chemical elements, for example, zinc, cobalt, manganese, copper, and iron, are in soils in extremely small amounts. They are essential to plant growth.