1. Tropical Red Soils
Latosols

2. 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.

3. Characteristics of Latosols
Low humus
Heavy leaching
Red colour
Sometimes can have a brick like surface.
Short nutrient cycle
Can support very rich vegetation.

5. 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.

6. Main Process Involved
Laterisation

7. 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.

8. Latosol Soil Profile

9. 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.

11. 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.

12. 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.