Soils in their environment - Fundamentals of the Physical Environment - page 432

(a) Impermeable parent material

Run-off

Soil Survey of
England and
Wales

Surface water
gley soil

Gleyic
brown earth

Surface water
gley soil

Gleyic
brown earth

Brown earth

Gleyic
Cambisol

Gleyic
Cambisol

FAO Gleysol Cambisol Gleysol

Drainage
class

Poor Imperfect Well Imperfect Poor

(b) Permeable parent material

Winter water table

Summer water table

Peat

Soil Survey of
England and
Wales

Ground water
gley soil

Brown earth or podzol Peat soil

FAO Cambisol or Podzol Gleysol Histosol

Drainage
class

Well Imperfect Very poor

Peat

Gleyic brown earth or gley podzol
Never waterlogged; unmottled
Occasionally waterlogged; slight mottling

Gleyic Cambisol or gleyic podzol

Seasonally waterlogged; strong mottling
Permanently waterlogged; typically grey or blue grey

Figure 18.4 Effects of relief and hydrology on soils and drainage class.

which produce the world's distinctive soil profiles and
their constituent horizons. The processes are as follows
and they will be discussed in the remainder of this chapter,
except for permafrost soil processes ( cryopedology ), which
are covered in Chapter 24, and rubefaction , which is
discussed in Chapter 25:

PROCESSES OF SOIL FORMATION
(PEDOGENIC PROCESSES)

The combined influence of the five factors of soil
formation is to produce a set of soil-forming processes