NCERT Solutions Soil for Class 7 Science

NCERT Solutions For Soil Class 7 Science Chapter 9 Soil focuses on teaching students about the characteristics, types and uses of soils present in our earth. Students must solve all the questions from the exercise prescribed in the NCERT textbook to strengthen their grip on the topics discussed. SimplyAcad has prepared the best NCERT Solutions Soil for Class 7 to assist students in solving those questions in an effective way. The solutions will give in-depth knowledge on the topics presented in the chapter, students can scroll below to find them.

Access to the Class 7 NCERT Solutions Soil

Question 1. In addition to the rock particles, the soil contains

• Air and water
• Water, and plants
• Minerals, organic matter, air, and water
• Water, air, and plants

Ans: (iii) minerals, organic matter, air, and water

Question 2. The water holding capacity is highest in

• Sandy soil
• Clayey soil
• Loamy soil
• A mixture of sand and loam.

Ans: (ii) clayey soil

Question 3. Match the items in Column I with those in Column II.

Column I

• i. A home of living organisms.
• ii. Upper layer of the soil.
• iii. Sandy soil
• iv. Middle layer of the soil.
• v. Clayey soil

Column II

• a) Large particles
• b) All kinds of soil.
• c) Dark in colour
• d) Small particles and packed tight.
• e) Lesser amount of humus.

Ans:

Column I	Column II
(i) A home of 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.

Question 4. Explain how soil is formed.

Ans: Soil is formed by the process of weathering. In this process, rocks break down by the influence of wind, climate, and water. The formation of soil is a slow process as it takes thousands of years.

Two Steps are Involved in Soil Formation:

1. Rock is first broken down into small pieces.
2. These pieces are mixed with the organic substance and form soil. Mechanical or physical weathering and biological weathering also support the formation of soil.

Question 5. How is clayey soil useful for crops?

Ans: Clayey soil has the property of good water retention. The number of organic particles present in the soil helps the clayey soil to retain water that is absorbed by the crops. Crops need a regular supply of water to grow. In this way, clayey soil is useful for crops. Clay particles are usually heavier in weight, and it supports the good growth of crops. It also has a low percolation rate. Therefore, clayey soil is useful for crops.

Question 6. List the difference between clayey soil and sandy soil.

Ans:

Clayey Soil	Sandy Soil
Clayey soil is fertile.	Sandy soil is not fertile.
In clayey soil, the particles present are tightly packed.	In sandy soil, the particles are loosely packed.
Clayey soil has a low percolation rate.	Sandy soil has a high percolation rate.
Clayey soil has a high water retention capacity.	Sandy soil has a low water retention capacity.
It supports the good growth of crops.	It does not support the good growth of crops.
Clay particles are usually heavier in weight.	Sandy particles are lighter in weight.

Question 7. Sketch the cross-section of soil and label the various layers.

Ans: The cross-section of soil is shown below.

Question 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.

Ans:

Rate of percolation =

$\frac{\text{Amount of water}}{\text{Percolation time}}$

Percolation timeAmount of water​

Rate of percolation =

$\frac{200\text{ mL}}{40\text{ min}}$

40 min200 mL​

Rate of percolation =

$5\text{ mL/min}$

5 mL/min

Question 9. Explain how soil pollution and soil erosion could be prevented.

Ans: Soil pollution is the contamination of the soil caused mainly by the waste materials discarded by humans and other human activities.

The soil pollution and soil erosion could be prevented by:

• Stopping cutting trees.
• Starting to grow more and more trees.
• Controlling and reducing the use of plastics.
• Treating the industrial waste before letting it out in the soil.
• Avoiding overgrazing of grasslands.

Question 10. Solve the following crossword puzzle with the clues given:

1. 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 desert soil erosion occurs through.
• Clay and loam are suitable for cereals.
• This type of soil can hold very little water.
• Collective name for layers of soil.

Ans:

Across:

1. WIND
2. EROSION
3. CLAY
4. EARTHWORM

Down:

1. WIND
2. EROSION
3. CLAY
4. POLYTHENE