4. Soils distinguished by Fe/Al chemistry –
Groundwater-affected, underwater and in tidal areas:
Allophanes or Al-humus complexes:
Subsoil accumulation of humus and/or oxides:
Accumulation and redistribution of Fe:
Low-activity clay, P fixation, many Fe oxides, strongly structured:
Dominance of kaolinite and oxides:
Stagnating water, abrupt textural difference:
Stagnating water, structural difference and/or moderate textural
difference: