Soil is Chapter 9 taken from JKBOSE and NCERT textbook of Science for students of Class 7th. In the previous post, I provided you with Questions and Answers for Chapter 8 Winds Storms and Cyclones. This post is about Soil Class 7th Science Question Answers. Before we proceed to Question Answers, you need to have basic information about the chapter you have studied in your classroom reading. So here is a brief overview of the chapter:
Soil Class 7th Science Question Answers
Overview of Chapter
The following topics are discussed in detail in this chapter:
- SOIL TEEMING WITH LIFE.
- SOIL PROFILE.
- SOIL TYPES.
- PROPERTIES OF SOIL.
- Percolation rate of water in the soil.
- MOISTURE IN SOIL.
- ABSORPTION OF WATER BY SOIL.
- SOIL AND CROPS.
SOIL TEEMING WITH LIFE: Soil contains air, water and countless living organisms like fungi, bacteria, insects, earthworms, rodents, moles and plant roots.
SOIL PROFILE: A vertical section through different layers of the soil is called the soil profile. These layers are referred to as horizons. Each horizon differs in texture, colour, depth and chemical composition. Different horizons of soil are as under:
- A- Horizon or Topsoil.
- B- Horizon or Subsoil.
- C- Horizon or Substratum.
- Bedrock or Parent Rock.
SOIL TYPES: The soil is classified based on the proportion of particles of various sizes. The different types of soil based size of particles are:
- Sandy Soil.
- Clayey Soil.
- Loamy Soil.
PROPERTIES OF SOIL: Soil contains air, can soak or absorb water, hold water or moisture and allows water to pass down through it. The percolation rate is the amount of water that is percolated through the soil in unit time. The rate of percolation differs in different soil types.
MOISTURE IN SOIL: Soil contains some water in it which is called soil moisture.
ABSORPTION OF WATER BY SOIL: The ability or capacity of the soil to absorb a limit of water is called absorption percentage.
SOIL AND CROPS: Different types of soils are found in different parts of India. In some parts, there is clayey soil, in some parts, there is loamy soil while in some other parts there is sandy soil.
That was a brief overview of what you have studied in this chapter. Now let us move on to the solutions of the chapter.
Exercises
Tick the most suitable answer in questions 1 and 2.
1. In addition to the rock particles, the soil contains
(i) air and water
(ii) water and plants
(iii) minerals, organic matter, air and water
(iv) water, air and plants
Ans. (iii) minerals, organic matter, air and water
2. The water holding capacity is the highest in
(i) sandy soil
(ii) clayey soil
(iii) loamy soil
(iv) mixture of sand and loam
Ans. (ii) clayey soil
3. The process of soil formation is called (JKBOSE)
(i) Conservation
(ii) Weathering
(iii) Erosion
(iv) Pedogenesis
Ans. (iv) Pedogenesis
4. Soil profile consist of (JKBOSE)
(i) Two layers
(ii) Three layers
(iii) Four layers
(iv) Five layers
Ans. (iii) Four layers
5. Humus is present in (JKBOSE)
(i) A-Horizon
(ii) B-horizon
(iii) C-Horizon
(iv) Bedrock
Ans. (i) A-Horizon
- Match the items in Column I with those in Column II:
| Column I | Column II |
|---|---|
| (i) A home for living organisms | (a) Large particles |
| (ii) Upper layer of soil | (b) All kinds of soil |
| (iii) Sandy soil | (c) Dark in colour |
| (iv) Middle layer of the soil | (d) Small particles and packed tight |
| (v) Clayey soil | (e) Lesser amount of humus |
Ans.
| Column I | Column II |
|---|---|
| (i) A home for living organisms | (b) All kinds of soil |
| (ii) Upper layer of soil | (c) Dark in colour |
| (iii) Sandy soil | (a) Large particles |
| (iv) Middle layer of the soil | (e) Lesser amount of humus |
| (v) Clayey soil | (d) Small particles and packed tight |
- Explain how soil is formed.
Ans. Soil is formed by the process of weathering. In weathering, rocks are broken down into tiny rock particles by the action of wind, water and climate. These rock particles then mix up with humus to form fertile soil.
- How is clayey soil useful for crops?
Ans. Clayey soil is rich in humus and has good water-retaining capacity. It is very fertile soil and has sufficient moisture content. So, it is very suitable for the growth of crops.
- List the differences between clayey soil and sandy soil.
| Clayey Soil | Sandy Soil |
|---|---|
| 1. This type of soil is made of very small particles. | 1. The particles are quite large in size. |
| 2. It has good water-holding capacity. | 2. It has poor water-holding capacity. |
| 3. There are no air spaces present between the particles. | 3. Lot of spaces are present between the particles of this type of soil. |
| 4. This soil has rich humus. | 4. This soil has little humus. |
| 5. It is suitable for the growth of plants. | 5. It is not suitable for plant growth. |
| 6. Water does not drain easily from this type of soil | 6. Water drains easily from this type of soil. |
- Sketch the cross-section of soil and label the various layers.
Ans.
- Razia conducted an experiment in the field related to the rate of percolation. She observed that it took 40 min for 200 mL of water to percolate through the soil sample. Calculate the rate of percolation.
- Explain how soil pollution and soil erosion could be prevented.
Ans. Here are some methods to prevent soil pollution and soil erosion.
Ans. Methods to Prevent Soil Pollution.
- Use of organic manure instead of fertilizers.
- Reduced use of pesticides.
- Ban on use of polythene bags and plastics.
- Treat industrial waste before releasing it into the soil.
Methods to Prevent Soil Erosion.
- Plantation of trees on a large scale.
- Avoid overgrazing grassland.
- Follow the terrace cultivation method in hilly areas.
- Protection of forests.
- Solve the following crossword puzzle with the clues given:
Across
- Plantation prevents it.
- Use should be banned to avoid soil pollution.
- Type of soil used for making pottery.
- Living organisms in the soil.
Down
- In the desert, soil erosion occurs through.
- Clay and loam are suitable for cereals like.
- This type of soil can hold very little water.
- Collective name for layers of soil.
Ans.
That’s all about Soil Class 7th Science Question Answers. Hope it has helped. Do share your views in the comment section below.
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