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Class 7 Science Chapter 9 Soil

Last updated on August 30th, 2023 at 01:00 am

NCERT Solutions for Class 7 Science Chapter 9 Soil

 

Tick the most suitable answer in questions 1 and 2.

Que. In addition to the rock particles, the soil contains

  1. air and water
  2. water and plants
  3. minerals, organic matter, air and water
  4. water, air and plants

 

Que. The water holding capacity is the highest in

  1. sandy soil
  2. clayey soil
  3. loamy soil
  4. mixture of sand and loam

 

Que. Match the items in Column I with those in Column II:

Column I  Column II
1. A home for living organisms a. Large particles
2. Upper layer of the soil b. All kinds of soil
3. Sandy soil c. Dark in colour
4. Middle layer of the soil d. Small particles and packed tight
5. Clayey soil e. Lesser amount of humus

Answers:- 1 – b , 2 – c , 3 – a , 4 – e , 5 – d

Que. Explain how soil is formed.

Wind, water, and climate break down rocks to form soil. This process is called weathering. The characteristics of any soil are determined by the rocks that form it and the types of vegetation that grows there.

 

Que. How is clayey soil useful for crops?

A clayey soil contains tiny particles packed tightly and able to hold water due to its small size. Clayey soils are rich in organic matter. Soil that is good at retaining water and rich in organic matter is good for growing crops such as wheat, gram, and paddy. Due to these characteristics, clayey soils are suitable for growing such crops.

 

Que. List the differences between clayey soil and sandy soil.

Clayey soil Sandy soil
Majority of Fine particles Majority of large particles
Particles are packed tightly Particles are loosely packed.
hold good amount of water cannot hold water
less aie is trapped more air is trapped
rich in organic matter not rich in organic matter

Que. Explain how soil pollution and soil erosion could be prevented.

Here are some ways to prevent soil pollution:

  • Recycle non-biodegradable wastes.
  • Limiting the use of pesticides and insecticides.

Erosion refers to the removal of land surface by water, wind, or ice. Here are some ways to prevent soil erosion:

  • Tree planting or afforestation.
  • Reduce the cutting down of trees or deforestation and (ii) Increase the planting of trees.
  • Step farming in hilly regions 

Class 7 Science Chapter 9 Extra Questions

What is humus?

Humus is a substance in soil that consists of decayed dead matter. Humus provides nutrients to the soil, making it fertile.

Define weathering ?

Soil is formed by the breaking down of rocks by the action of wind, water and climate. This process is called weathering.

Define soil in short ?

Soil is a mixture of rock particles and humus.

What is loamy soil?

A loamy soil is composed of sand, clay, and another kind of soil particle called silt.

Define horizons in soil?

Horizons are layers of soil. Generally, soils are categorized into four types based on their horizons: A-horizon, B-horizon, C-horizon, and bedrock.

 

Additional Question and Answers from the Chapter

Q1: What is soil and why is it important for life on Earth?

A1: Soil is the uppermost crust that covers the Earth, consisting of a mixture of rock particles and humus. It is important for life on Earth as it provides nutrients, water, and a habitat for various organisms, and supports agriculture for human food production.

 

Q2: What are the three main processes involved in soil formation?

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