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4 SOIL

Learning Objectives

 Formation of Soil
 Types of Soil
 Soil Profile
 Soil Erosion
 Soil conversation

Let’s Start Learning

Soil is one of Earth’s most precious resources. It provides the support and
nourishment that plants need in order to grow. Soil contains sand, minerals, organic
matter and some amount of water and air. It is a complex mixture of sand, silt, clay and
bits of decaying animal and plant tissue. The ingredients in a soil define what type of soil
it is and what is able to grow in it.

Formation of Soil

Soil formation is a long slow process. It's estimated that an

inch of soil takes 500 to 1000 years to form. Soil is formed

from rock. By the action of sun, rain and wind, parent rocks

break down into smaller pieces. Later these rock pieces

collide with each other and ground to convert into very

small pieces. The soil so formed is

called silt or sand. This process of

breaking down of rock into very

small pieces is called weathering.

The sand or silt when mixes with

remains of dead plants and animals

and minerals, soil is formed. Weathering of rock Soil formation

For the Teacher Discuss in the class about formation of soil, soil profile and different

types of soil. Also discuss about soil erosion and soil conservation.

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