Tropical Red Soils
Latosols
Zonal Soils of Equatorial
Regions
• Occur in the continents of South America,
Africa and South Asia.
• They are found near the equator.
• For example in Brazil.
• These countries all have an equatorial
climate, that is very warm and very wet.
• Called Latosols.
Characteristics of Latosols
•
•
•
•
Low humus
Heavy leaching
Red colour
Sometimes can have a
brick like surface.
• Short nutrient cycle
• Can support very rich
vegetation.
Causes of Characteristics….
• Low humus content is
due to the rapid
breakdown of organic
material due to the
very hot and very wet
climate.
• Leaching is intense,
only iron and
aluminium compounds
remain,this gives soil
its red colour.
• The nutrient cycle is
short because there is
fast plant growth and
rapid decomposition.
This means humus is
formed and used
before leaching
occurs.
Main Process Involved
Laterisation
Laterites
• Loose topsoil is eroded.
• Iron and aluminium layers are exposed.
• The high temperatures bake this into a hard
brick like surface.
• This surface cannot be cultivated.
• It is known as a laterite.
Latosol Soil Profile
Latosol Soil Profile
• O Horizon; A lot of organic matter, rapid
decomposition.
• A Horizon; Very thin layer due to short
nutrient cycle.
• B Horizon; Very deep, intense leaching.
• C Horizon; Parent rock.
Uses of Latosol Soils
• In many areas with latosol soils there are
tropical rainforests.
• The soil type can be an obstacle to the
development of profitable agriculture.
• If forest or vegetation is removed the soil
can become infertile within a couple of
years.
Exam Questions
• Compare and contrast the characteristics of
any two soil types which you have studied.
(80 marks)
– Characteristics; Colour, Texture, Structure,
Humus, PH Value, Water content, Fertility.
– Also contrast the processes causing these
characteristics, climate, locations and uses.