Term
|
Definition
-semi arid to moist areas -weathering leaches clay minerals and other constituents into subsoil -formed primarily under forest or mixed vegetation -usually productive |
|
|
Term
|
Definition
-cool areas with moderate to high ppt -especially associated with volcanic PM -weathering generates minerals with little crystalline structure -high water and nutrient holding capacity -highly productive |
|
|
Term
|
Definition
-soils that are too dry for mesophytic plant growth -common in deserts -lack of moisture restricts weathering and limits development -accumulates gypsum, CaCO3, and other soluble materials |
|
|
Term
|
Definition
(polygenetic) -many environments -little to no pedogenic horizon development -recently deposited PM or erosion/deposition is faster than soil development |
|
|
Term
|
Definition
-higher latitudes and elevations -soils with permafrost or cryoturbation or ice segregation |
|
|
Term
|
Definition
-usually saturated year round (bogs and moors) -high content of O matter (peat or muck) -decomposed plant matter accumulates in water |
|
|
Term
|
Definition
-semi arid to humid areas -moderate degrees of soil weathering and development -wide range of characteristics in a wide variety of climates |
|
|
Term
|
Definition
-moderate to pronounced seasonal moisture deficit areas -dark colored surface horizon -relatively high O matter content -base rich throughout -characteristically form under grass in appropriate climates (Steppes) |
|
|
Term
|
Definition
-tropical and subtropical areas -highly weathered -dominated by low activity minerals (quartz, kaolinite, iron oxides) -indistinct horizons -low natural fertility and low capacity to retain additions |
|
|
Term
|
Definition
-humid areas -coarse-textured deposits under coniferous forests in humid regions -weathering processes strip O matter combined with Al (and sometimes Fe) from surfaces and deposit in subsoil -gray eluvial horizon and dark subsoil sometimes -tend to be acidic and infertile |
|
|
Term
|
Definition
-humid areas -fairly intense weathering and leaching resulting in clay-enriched subsoils dominated by minerals (i.e. quartz, kaolinite and iron oxides) -typically acid soils, most nutrients in upper few inches -moderately low capacity to retain additions |
|
|
Term
|
Definition
-high content of expanding clay minerals -undergo pronounced volume changes with change in moisture -cracks that open and close, show movement in soil profile -swell when wet (transmit water slowly, little leaching) -high natural fertility |
|
|