NCERT Solutions for Class 7 Science, Chapter 9 – Soil is available here for download in PDF format. You can also download Chapter 9 – Soil of NCERT Class 7 Science textbook with the help of download link given at the end of this article.
NCERT Solutions for Class 7 Science, Chapter 9 – Soil: Questions & Answers
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
Option (iii) i.e., minerals, organic matter, air and water is the correct option.
2. The water holding capacity is the highest in
(i) sandy soil
(ii) clayey soil
(iii) loamy soil
(iv) mixture of sand and loam
Option (ii) i.e., clayey soil is the correct option.
3. Match the items in Column I with those in
Column I: Column II:
(i) A home for living organisms (a) Large particles
(ii) Upper layer of the 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
(i) A home for living organisms (b) All kinds of soil
(ii) Upper layer of the 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
Question4. Explain how soil is formed.
The soil is formed by the breaking down of rocks by the action of wind, water and climate. This process is called weathering. The nature of any soil depends upon the rocks from which it has been formed and the type of vegetation that grows in it.
5. How is clayey soil useful for crops?
Water retention capacity of the clayey soil is quite high. Also, clayey soil is rich in humus and is very fertile. Hence, clayey soil useful for crops (such as wheat).
6. List the differences between clayey soil and sandy soil.
Percolation rate is least in Sandy Soil.
Percolation rate is highest in Sandy Soil.
Water retention capacity is higher.
Water retention capacity is low.
7. Sketch the cross section of soil and label the various layers.
8. 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.
Given, amount of water = 200 ml, percolation time = 40 minute
Now, Rate of Percolation = 200 ml/40 minute = 5 ml/minute.
9. Explain how soil pollution and soil erosion could be prevented.
Both soil pollution and soil erosion can be prevented by preventing deforestation and planting more and more tress.
10. Solve the following crossword puzzle with the clues given:
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil.