Page 106 - ACTIVE SCIENCE 4 TOC

4. The process which reduces the soil quality is _____________.
a. soil erosion b. soil profile

c. soil conservation d. terrace farming

B. Fill in the blanks.

1. The bottom layer of the soil is called _____________.
2. The process of growing different crops on the same farmland is called _____________.

3. The organic matter present in the topsoil is called _____________.

4. Prevention of soil erosion is called _____________.

C. State whether the following statements are true or false:

1. Topsoil is rich in humus, air and water. ______
2. Subsoil is the lowest layer of the soil. ______

3. Soil erosion reduces the soil quality. ______

4. Planting of trees prevents erosion of soil. ______

D. Short Answer Questions.
1. What is weathering?

2. What is soil erosion?
3. What is crop rotation?

4. What are the main types of soil?

E. Long Answer Questions.

1. What is soil conservation? List the methods of conservation.
2. Describe the soil profile with a suitable diagram.

3. Write about the process of formation of soil.
4. Compare four different types of soil.

Think Hard

Soil is often called the skin of the earth. Why?

Project Work

Divide the class into groups. Each group creates a model of the soil profile. Topics such as

soil formation, soil conservation and soil erosion, etc., can be divided amongst the groups
on which they will create a presentation.

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