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Q1. Why do plants not grow well in sandy soil?

• Lack of minerals
• Less air spaces
• Does not hold water
• Contains very little humus

Solution

Sandy soil has more air spaces and so, its water retaining capacity is low. Therefore, it is less fertile and does not support plant growth. 

Q2. Which of the following clearly defines soil erosion?

• Process of soil formation
• Removal of top layer of soil
• Process of layer formation in soil
• Contamination of soil

Solution

Removal of fertile top layer of the soil by wind or water is called soil erosion.

Q3. Percolation rate of water in sand is:

• Low
• Moderate
• High
• Very high

Solution

Very high

Q4. How are essential minerals supplied to the soil?

• By adding peat
• By adding lime
• By adding humus
• By adding fertilisers

Solution

Fertilisers are rich in essential minerals. The addition of fertilisers to the soil makes the essential minerals available to the soil.

Q5. What is the major disadvantage of clayey soil?

• No enough aeration to the plant roots
• Becomes water-logged
• High content of organic matter 
• No aeration to the plant roots and also becomes water-logged

Solution

Clayey soil has less air spaces and so, it does not provide much air for the breathing of plant roots. It has high water retaining capacity which often makes the soil water-logged. 

Q6. Loamy soil is a mixture of

• Sand and silt
• Clay and silt
• Sand, clay and silt
• Sand and clay

Solution

Loamy soil is a mixture of sand, clay, silt and humus in the right proportions.

Q7. The crop grown mainly on desert soil is

• Millet
• Rice
• Wheat
• Maize

Solution

Millet grows well in sandy desert soil because it drains water easily and also provides good aeration for plant growth.

Q8. Why is soil water important for the growth of plants?

• It contains dissolved nutrients.
• It has air.
• It helps in easy ploughing of the field.
• It increases the water table.

Solution

Soil water is important because it contains dissolved nutrients which promote good growth of plants.

Q9. Which type of soil is best suited for growing wheat and rice?

• Sandy soil
• Loamy soil
• Clayey soil
• Silt

Solution

Loamy soil is best suited for the growth of wheat and rice because it is rich in humus and very fertile.

Q10. Cotton grows well in

• Sandy soil
• Loamy soil
• Clayey soil
• Sandy-loam soil

Solution

Cotton grows well in sandy-loam soil which drains water easily and can hold plenty of air in it.

Q11. Top soil is dark in color as compared to other horizons because

• It is rich in minerals and humus.
• It is rich in plant life.
• It is rich in dead and decaying organic matter.
• It is rich in animal life.

Solution

Top soil is dark in colour because it is rich in minerals and humus.

Q12. X is a type of soil which is light in weight and can be easily carried away by wind? What is X?

• Sandy soil
• Loamy soil
• Clayey soil
• Silt

Solution

Sandy soil is light and has a tendency to be blown away by wind if left bare.

Q13. How does percolation rate of water affect the fertility of soil? (A) It affects the water retaining capacity of soil. (B) It affects the availability of water to plants. (C) It affects the rate of erosion of soil.

• (A) and (B)
• (A) and (C)
• (B) and (C)
• (A), (B) and (C)

Solution

The percolation rate of water affects the water retention capacity of the soil, the availability of water to the plants and keeps a check on soil erosion. 

Q14. Which of the following refers to humus?

• Small pebbles
• Minerals
• Organic matter
• Big pieces of rocks

Solution

The organic matter formed by the decomposition of dead plants and animals by microorganisms is called humus.

Q15. Which of the following is a characteristic of desert soil?

• Rich in humus
• Good aeration
• High water holding capacity
• High fertility

Solution

Sandy soil has large particles with large air spaces between them. Therefore, it provides good aeration to the plant roots and can be ploughed easily.

Q16. Which of the following does not cause soil pollution?

• Use of jute bags
• Excessive use of pesticides
• Discarding used glass bottles
• Dumping industrial wastes

Solution

Use of jute bags instead of polythene bags helps in preventing soil pollution.

Q17. Which of the following factors affect the growth of plants? (A) Water absorption capacity of soil (B) Water holding capacity of soil (C) Humus content

• (A) and (B)
• (B) and (C)
• (A) and (C)
• (A), (B) and (C)

Solution

Factors such as water absorption capacity, water holding capacity and humus content affect the growth of plants in soil.

Q18. Loamy soil is a mixture of

• Sand and silt
• Clay and silt
• Sand, clay and silt
• Sand and clay

Solution

Loamy soil is a mixture of sand, clay, silt and humus in the right proportions.

Q19. Which one of the following types of soil has the highest humus content?

• Sandy soil
• Loamy soil
• Clayey soil
• Silt

Solution

Loamy soil contains sufficient amount of humus necessary for good growth of plants.

Q20. Which gas is required by the roots of plants?

• Carbon dioxide
• Oxygen
• Nitrogen
• Argon

Solution

Oxygen is required by the roots of plants for respiration.

Q21. Where is silt found?

• River bed
• River bank
• Open field
• Seashore

Solution

Silt is found as deposits on the river beds.

Q22. Which of the following are advantages of sandy soil? (A) Good aeration (B) High percolation rate (C) Helps in recharging groundwater

• (A) and (B)
• (B) and (C)
• (A) and (C)
• (A), (B) and (C)

Solution

Sandy soil has large air spaces and so it provides good aeration to the plant roots. Water can easily drain through the spaces between the sand particles. Therefore, it has a high percolation rate and helps in recharging groundwater.  

Q23. Soil is necessary for plant growth because (A) Provides mechanical support to plants (B) Provides nutrients to plants (C) Provides water and aeration to plants

• (A) and (B)
• (B) and (C)
• (A) and (C)
• (A), (B) and (C)

Solution

Soil is necessary for plant growth because it not only provides mechanical support but also nutrients, water and good aeration to the plants.

Q24. Which type of soil is considered best for the growth of plants?

• Clayey soil
• Sandy soil
• Loamy soil
• Silt

Solution

Loamy soil has particles of medium size. It has average water retaining capacity and its fertility is optimum. Therefore, loamy soil is considered best for the growth of plants.

Q25. Which of the following is the least fertile soil?

• Sandy soil
• Loamy soil
• Clayey soil
• Sandy-loam soil

Solution

Sandy soil is the least fertile soil because it contains very little humus and least water holding capacity.

Q26. Sandy soil is composed of

• Sand
• Clay
• Sand and clay
• Sand and silt

Solution

Sandy soil contains mainly sand with hardly any clay or silt in it.

Q27. Desert soil consists of sand. Then, how is it capable of supporting plant growth?

• It is rich in humus.
• It has large-sized particles.
• It has good water retention capacity.
• It is rich in minerals and provides good aeration.

Solution

Although the desert sandy soil contains very little humus and has poor water retention capacity, it is still able to support plant growth because it is rich in minerals and provides good aeration for the roots of plants.

Q28. Which of the following clearly defines soil erosion?

• Process of soil formation
• Removal of top layer of soil
• Process of layer formation in soil
• Contamination of soil

Solution

Removal of fertile top layer of the soil by wind or water is called soil erosion.

Q29. The process by which huge rocks are broken down into small particles by the action of heat, wind, rain and flowing water is called

• Weathering
• Erosion
• Leaching
• Decomposition

Solution

The process by which huge rocks are broken down into small particles by the action of heat, wind, rain and flowing water is called weathering.

Q30. Sandy soil is composed of

• Sand
• Clay
• Sand and clay
• Sand and silt

Solution

Sandy soil contains mainly sand with hardly any clay or silt in it.

Q31. How does percolation rate of water affect the fertility of soil? (A) It affects the water retaining capacity of soil. (B) It affects the availability of water to plants. (C) It affects the rate of erosion of soil.

• (A) and (B)
• (A) and (C)
• (B) and (C)
• (A), (B) and (C)

Solution

The percolation rate of water affects the water retention capacity of the soil, the availability of water to the plants and keeps a check on soil erosion. 

Q32. Which of the following does not fit in the group?

• Colour
• Water absorption capacity
• Fertilisers
• Moisture content

Solution

Colour, water absorption capacity and moisture content are the properties of soil.

Q33. Which of the following will not help in preventing soil pollution?

• Minimise the use of pesticides and fertilisers.
• Treat the industrial wastes before releasing them.
• Send used glass bottles and other metal objects for recycling.
• Encourage the use of plastic bags instead bags made of cloth, jute or paper.

Solution

Use of plastic bags should be avoided to prevent soil pollution. This can be done by using bags made of paper, cloth or jute.

Q34. Cotton grows well in

• Sandy soil
• Loamy soil
• Clayey soil
• Sandy-loam soil

Solution

Cotton grows well in sandy-loam soil which drains water easily and can hold plenty of air in it.

Q35. Which is the largest and the smallest rock particles present in soil?

• Largest - gravel, smallest - clay
• Largest - sand, smallest - silt
• Largest - gravel, smallest - silt
• Largest - clay, smallest - sand

Solution

Soil is formed from weathered rocks which contain gravel, fine and coarse sand, silt and clay. The largest particle is gravel, and the smallest one is clay.

Q36. How can clayey soil be made more fertile?

• By adding peat
• By adding lime
• By adding salts
• By adding sand and humus

Solution

Clayey soil can be made more fertile by adding some sand and humus to it. Sand improves the drainage whereas humus provides the necessary plant nutrients.

Q37. Which of the following factors affect the growth of plants? (A) Water absorption capacity of soil (B) Water holding capacity of soil (C) Humus content

• (A) and (B)
• (B) and (C)
• (A) and (C)
• (A), (B) and (C)

Solution

Factors such as water absorption capacity, water holding capacity and humus content affect the growth of plants in soil.

Q38. Which of the following is not a preferred method for improving soil fertility?

• Altering the pH of soil
• Altering the air content of soil
• Adding organic fertilisers to the soil
• Adding chemical fertilisers to the soil

Solution

Excess use of chemical fertilisers alters the soil pH and composition and thereby decreases its fertility.

Q39. Which of the following does not fit in the group?

• Colour
• Water absorption capacity
• Fertilisers
• Moisture content

Solution

Colour, water absorption capacity and moisture content are the properties of soil.

Q40. Which of the following statements is false with respect to soil?

• Soil has uniform composition.
• Soil has non-uniform composition.
• Soil consists of organic matter.
• Soil is essential for the existence of life on the Earth.

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