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SOIL

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Learning Objectives

To Understand:
• Soil formation • Soil composition
• Types of soil • Soil profile

• Soil erosion • Soil conservation

To Find Out:
• About weathering • What is top soil, subsoil and bedrock?
• The colour and size of the soil

Let’s Begin

Soil is a very important natural resource. Plants grow in soil. Human and animals

depend on plants for their food. Besides producing food, soil also acts as a home to
a variety of insects and animals.

F ormation Of Soil

The development of soil is a slow process as it takes hundreds of years to form just

1cm of soil. Natural agents such as the heat of the sun, strong winds and flowing

water break the big rocks into small pieces leading to the formation of soil. This

process is called weathering.

The roots of plants grow and penetrate the rocks to break them into small particles.

Burrowing animals also break rocks into smaller pieces. These small pieces further

disintegrate into small sized, fine textured particles called sand. In this way, a
thin layer of soil is created. The remains of dead plants and animals are broken

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