Soil Profile

A vertical section cutting through the soil showing the different layers of the soil is called a ‘soil profile.’ A soil profile can be seen by looking at the sides of a recently dug trench, or while digging a well, or a foundation of a building. It can also be seen at the sides of a road on a hill.

Soil has three different layers or horizons:

1. Top Soil
2. Sub Soil
3. Sub Stratum

1. Top Soil

The top layer of the soil is called the Top Soil. Its properties are as follows:

• It is the most useful part of the soil.
• It is dark in color because it is rich in minerals and humus.
• Plant roots grow in the top soil.
• Many living things like insects, worms, rodents etc. live in the top soil.
• Bacteria and Fungi also occur in the top soil.
• It contains the decayed remains of dead plants and animals, which forms Humus. Humus makes the top soil very fertile.
• It is soft and porous and can hold a lot of water.
• Plants get all the minerals required for their growth, from the top soil.

2. Sub Soil

The layer of soil just below the top soil is called the Sub Soil. Its properties are as follows:

• It is lighter in color than the top soil.
• It has very little humus.
• It is made up of slightly bigger rock particles than the top soil.
• It is harder and more compact than the top soil.
• It contains very little living organisms.
• Roots of trees are able to reach the sub soil.
• It is much less fertile than the top soil, but it is rich in soluble minerals.

3. Sub Stratum

The layer of soil just below the sub soil is called the Sub Stratum. Its properties are as follows:

• It mainly consists of partially broken or weathered rocks.
• These rocks keep breaking from the bed rock which is below the sub stratum.

Below the sub stratum we have the bed rock (or parent rock), which is just unweathered solid rock.
It is this bed rock which has produced soil over a long period of time.

Wind, temperature, rainfall, light and humidity are some important climatic factors which affect the soil profile and bring changes in the soil structure.

For more interesting Geography articles and videos, visit: https://mocomi.com/learn/geography/