TOPIC 3: STUDY OF SOILS IN GEOGRAPHY - PHYSICAL GEOGRAPHY FORM 5 & 6
Sub-topics:
i. Concepts of soils and soil profile
ii. Soil formation
iii. Soil classification
iv. Soil fertility
v. Loss of soil fertility
vi. Soil conservation and management
CONCEPTS OF SOILS
Soil is the upper most layer of the earth crust which support plant growth. OR Soil is the mixture of organic matter, mineral matter, water and air.
The scientific study of soil refers as Pedology and person dealing with this study are called pedologists.
BRANCHES OF SOIL
Soil can be divided into two (2) major branches. These are;
i. Pedology:
This branch deals with soils in relation to their formation (genesis), classification and distribution in nature.
ii. Edaphology:
This branch deals with soils in relation to their role in plant growth.
IMPORTANCE OF SOILS
i. Soils support plant growth which includes a wide range of vegetation and crops, depending on the type of soil.
ii. Soil also determines the type of natural vegetation of a place.
iii. In addition, soil is used in the construction of buildings and making of pottery which uses well sieved soil, for example, sand and clay.
iv. Soils are habitats for living organisms such as ants, bacteria, earthworms and snakes.
v. Furthermore, in a battle ground, people might make tunnels in the ground for protection.
vi. Dead bodies and other rubbish are buried in the soil, which decompose and add humus to the soil, thus contributing to soil fertility.
vii. In addition, soil is a source of minerals since it is derived from parent materials of different composition.
viii. Researchers use soils to investigate mineral content, to support agricultural development.
COMPONENTS / COMPOSITION OF SOILS
There are four (4) components of soils. These are;
a) Organic matter
b) Mineral matter / Inorganic matter
c) Water
d) Air