Page 66 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

4. B-horizon is also called ....................... .

(a) Topsoil (b) Subsoil (c) Parent rock (d) Substratum

Ans. (b)

5. Humus helps in making the soil ....................... .

(a) Thick (b) Hard (c) Fertile (d) Dead
B. Fill in the blanks.

1. ....................... soil can hold very little water.

Ans. Sandy

2. The water-holding capacity is the maximum in ....................... soil.

Ans. clayey
3. Each layer of soil differs in texture, colour, depth and ....................... .

Ans. chemical composition

4. Soil of some areas are red in colour due to the presence of ....................... of iron.

Ans. oxides

5. Upper layer of soil is ....................... in colour.
Ans. dark

6. Removal of the fertile topsoil by wind or water is called ....................... .

Ans. soil erosion

7. Wheat and gram require ....................... and ....................... soil for growth while rye

grows in ....................... soil.
Ans. clayey, loamy, sandy-loam

C. State whether the following statements are true (T) or false (F).

1. Humus is important for soil fertility.

2. Cotton is grown in sandy soil.

3. Soil erosion takes place in areas of heavy vegetation.

4. Soil is affected by climatic factors.
5. In deserts, soil erosion takes place in areas of heavy vegetation.

6. Every soil has a water-absorption capacity which depends upon how porous it is.

7. Sandy soil is light, aerated and dry in nature.

8. Use of fertilisers, pesticides, insecticides or use of certain chemicals does not affect

the soil adversely.

Ans. 1. (T) 2. (F) 3. (F) 4. (T) 5. (F) 6. (T) 7. (T) 8. (F)

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