Page 33 - SST Class 04

1. Alluvial Soil

You know that many rivers originate in the mountains. As they
flow, they break and scratch rocks. These pieces further break
down into smaller pieces and silt. This silt is also called
alluvium . The water current carries this silt with it. When these
rivers leave the mountains and enter the plains, their flow slows
down. With this, the silt settles down in layers and forms soil.
This type of soil is called alluvial soil. This is the most fertile

type of soil. A cotton field
Both the northern and coastal plains in our country have been formed by the silt

brought by rivers. Alluvial soil is suitable for the crops of wheat, rice, sugarcane,
millets, jute, pulses, oilseeds, vegetables, fruits etc.
Know It!

v The Ganga enters the plains at Haridwar. When its current slows down, the silt
in it settles down and a new layer of soil is formed. This is how alluvial soil is
formed in the Ganga basin. This happens with other rivers also.

2. Black Soil

The earth is very hot inside. It is so hot that even rocks melt. This molten rock is called
lava . When there is a crack in the earth’s surface, this hot lava flows out. Outside, it
cools down and becomes black rock again. When this rock is broken by the forces of
wind, water and temperature, black soil is formed.

Black soil is rich in minerals, like lime, iron ore, magnesium, phosphorus, nitrogen etc.
It is very suitable for the cotton crop. Besides, the crops of sugarcane, millets, tobacco
and wheat are grown in this soil. We can find black soil in the Malwa Plateau and

central part of the Deccan Plateau.

3. Red Soil
Commonly, red soil is reddish, but it can also be brownish, blackish or grayish. It is
formed from a rock called laterite, so it is also called laterite soil . It contains iron, so it
is reddish in colour.

Red soil is not very fertile and is used for growing coarse grains like jowar, bajra,
pulses and groundnut. It is found in a large part of South India.

4. Sandy Soil

Sometimes rocks do not break into fine soil. It results into grainy soil. It is called sandy
soil. This type of soil cannot hold water.

India : Soils 33