Soil - Questions and Answers - Class 4 Science

Soil - Class 4 Science



1. The top layer of our earth is made up of soil.
2. It takes a very long period for a little amount of soil to be formed.
3. Wind and water help to break down the rocks and thus lead to the formation of soil.
4. Clayey soil, sandy soil, loamy soil and gravel are the different kinds of soil.
5. Topsoil, subsoil and bedrock are the three layers of soil.
6. Plants grow in the topsoil.
7. Soil erosion reduces the fertility of the soil.
8. Protection of soil from being blown away or washed off is called soil conservation.

1. Loamy soil is very fertile and good for cultivation.
2. The layer of soil found below the topsoil is called subsoil.
3. Clayey soil is smooth and soft.
4. Protection of soil from being washed away is called soil Conservation.
5. Humus Makes the soil rich and fertile.
6. Bedrock is the bottom layer of soil.
7. Terrace farming is practised in hilly areas.
8. Dams help to check floods.
9. Soil formation is a slow process.
10. Humus makes the soil rich and fertile.
11. Gravel is mostly made up of small stones and pieces of rocks.
12. Clayey soil is used for making pots and toys.
Write 'T' for true and 'F' for false statements given below:
1. Terrace farming protects the loss of topsoil in the hills. [T]
2. Wind does not cause soil erosion at all. [F]
3. Planting of trees prevents soil erosion. [T]
4. Gravel is made up of sand particles. [F]
5. Soil is not important for us. [F]
6. Plants grow in the bedrock. [F]
7. Crop rotation reduces the fertility of soil. [F]
8. Strong winds and water can cause soil erosion. [T]


Soil is the topmost layer of the earth's crust. It is and Organic a mixture of sand, mineral substances

Ans- Depending on nature, colour and size of particles, soil can be classified into four types-
i) Clayey soil,
ii) Sandy soil,
iii) Loamy soil,
iv) Gravel
3. How does soil erosion take place?
Soil erosion takes place due to some major causes, like-
a) Deforestation.
b) strong and stormy winds
c) Heavy rainfall.
4. How can we prevent soil erosion?
We can prevent soil erosion through some action like-
a) Afforestation
b) Terrace farming
c) Crop rotation
5. What is Crop rotation?
The practice of growing a series of dissimilar types of crops in the same field in sequential seasons is known as crop rotation.

6. Explain the different layers of soil.

soil is made up of different layers. These layers are-
i)

Topsoil

- It is the upper most layer of the soil. It is very dark in colour due to the presence of humus. It is very fertile and good for growing crops.
ii)

Subsoil

- It is found below the topsoil. It is a light-coloured which is full of broken rock and sand. It is thicker and harder than topsoil. The humus content is less in the subsoil.
iii)

Bedrock

- It is the bottom layer of soil. It is mainly made up of solid rocks and stones. The upper layer of rocks in the bedrock is non-porous, therefore it does not allow water to pass through.
7. Write a short note on terrace farming.

Terrace farming is the method of growing Crops on hilly areas to reduce the soil erosion. In this method, terraces or furrows are made along the hill-slopes parallel to the Contours to check the erosion of soil. When water runs down the slopes, its force decreases Considerably due to the furrows and less amount of soil is washed away.

08. Why are dams built across rivers?

Dams are built across rivers to check floods.

09. Write two slogans on soil conservation.
i) Healthy soil, healthy food, healthy planet.
ii) Protect soil, prevent erosion.
iii) Save the soil, feed the world.