Soils are categorized into 3 types. They are Group-I , Group-II and Group-III
Group
I
Soils with well developed horizons or with fully weathered
minerals, resulting from long-continued adjustmet to prevailing soil
temperature and soil water conditions.
·
Oxisols: Very old, highly weathered soils of low
latitudes, with a subsurface horizon of accumulation of mineral oxides and very
low base status.
·
Ultisols: Soils of equatorial, ropical, and subtropical
latitude zones, with a subsurface hjorizon of clay accumulation and low base
status.
·
Vertisols: Soils of e subtropical and tropical zones with high clay content and high base
status. Vertisols develop deep, wide cracks when dry, and the soil blocks
formed by cracking move wih respect to each other.
·
Alfisols: Soils of humid and subhumid climates with a
subsurface horizon of clay accumulation and high base status. Alfisols range from equatorial to subarctic
latitude zones.
·
Spodosols:
Soils of cold, moist climates, with a well-developed B horizon of illuviation
and low base status.
·
Mollisols: Soils
of semiarid and subhumid midlatitude grasslands, with a dark,
humusd-rich epipedon and very high base status.
·
Aridisols:
Soils of dry climates, low in organic matter, and often haivn subsurface
horizons of accumulation of carbonate minerals or soluble salts.\
Group
II
Soils with a large proportion of organic matter
·
Histosols: Soils with a thick upper layer very rich in organic matter.
Group
III
Soils with poorly developed
horizons or no horizons, and capable of further mineral alteration.
·
Entisols:
Soils lacking horizons, usually because their parent material has accumulated only recently.
·
Inceptisols:
: Soils with weakly developed horizons,
having minerals capable of further
alteration by weathering
processes.
·
Andisols:
Soils with weakly developed horizons,
having a high proportion of glassy volcanic parent material produced by erupting volcanoes.