Science - Chapter 9 - Soil
Class - 7
NCERT - Important
Questions
Very Short Answer Type Questions
Question 1: Name an important natural
resource that supports growth of plants.
Answer: Soil.
Question 2: Name major soil pollutants.
Answer: Polythene bags, plastics, waste products, chemicals
and pesticides.
Question 3: Waste products and chemicals should be treated before
they are released into the soil. True/False.
Answer: True
Question 4: Define humus.
Answer: The rotting dead matter in soil is called humus.
Question 5: What do you mean by soil profile?
Answer: A vertical section through different layers of the
soil is called the soil profile.
Question 6: What is soil?
Answer: Soil is the crust part of the earth. It is mainly
the mixture of rock particles and humus.
Question 7: Name the process by which soil is formed.
Answer: Weathering
Question 8: Name the soil with highest water absorption rate.
Answer: Sandy soil.
Question 9: Name the soil having very less space between particles.
Answer: Clayey soil
Question 10: Clay soils are heavy and hold more___,
Answer: Water
Question 11: Ram has to grow wheat crop in his field, what kind of
soil he will prefer?
Answer: Clayey soil
Question 12: Name some places with severe soil erosion.
Answer: Areas of little or no surface vegetation, such as
deserts and barren lands.
Question 13: Classify soil on the basis of appearance and properties
of particles.
Answer: Sandy soil, Clay soil and Loamy soil
Question 14: State one property of sandy soil.
Answer: Sandy soils are light, well aerated and dry.
Question 15: State one property of loamy soil.
Answer: It is a mixture of sand, soil and silt. And also
contain humus.
Question 16: State one property of clayey soil.
Answer: It is made of a relatively high proportion of fine
particles.
Question 17: What is deforestation?
Answer: Clearing or Removal of forests or stands of trees.
Question 18: Name the soil horizon which contains humus.
Answer: A Horizon
Question 19: Upper layer of soilis__..__in colour.
Answer: Dark
Question 20: Why is uppermost layer of soil, dark in colour?
Answer: Because it is rich in humus and minerals.
Question 21: Middle layer of soil contains less amount of -------------
Answer: Humus
Question 22: Suggest an alternative of chemical fertilizer.
Answer: Manures
Question 23: Does Acid rain cause soil pollution or not?
Answer: Yes
Question 24: Plastics and poly bags should get mixed in soil.
True/False
Answer: False
Question 25: Humus is important for soil fertility. True/False
Answer: True
Question 26: If the amount of large and fine particles is about the
same, then soil is called --
Answer: Loamy
Question 27: What is bedrock?
Answer: After the C horizon, there lies bedrock which is
hard and difficult to dig with a spade.
Question 28: Name the layer of soil having lesser amount of humus but
more of minerals.
Answer: B horizon.
Question 29: What kind of soil is used for making matkas and toys?
Answer: Clay soil
Question 30: Give the formulae for percolation rate.
Answer: Percolation rate = amount of water (mL)/ Percolation
time (min)
Question 31. Name the best soil for growing plants.
Answer: Loamy soil
Question 32. What Is soil?
Answer: The mixture of rock particles and humus is called
the soil.
Question 33. Which type of soil is well aerated?
Answer: Sandy soil is well aerated.
Question 34. Which soil has
the highest percolation rate?
Answer: Sandy soil has the highest percolation rate.
Question 35. Which soil has the least percolation rate?
Answer: Clayey soil has the least percolation rate.
Question 36. What is humus?
Answer: The rotting dead matter in the soil is called humus.
Question 37. What is the role of humus in the soil?
Answer: The humus makes the soil fertile and provides
nutrients to growing plants.
Question 38. What is soil profile?
Answer: A vertical section through different layers of the
soil is called the soil profile.
Question 39. What is loamy soil?
Answer: Loamy soil is a mixture of sand, clay and another
type of soil particle known as silt.
Question 40. What is bedrock?
Answer: Just below the C-horizon is the bedrock, which is
hard and difficult to dig with a spade.
Question 41. Which type of soll is best for growing wheat and gram?
Answer: Clayey and loamy soils are both suitable for growing
cereals like wheat and gram.
Question 42. Which areas experience more severe soil erosion?
Answer: Erosion of soil is more severe in areas of little or
no surface vegetation, such as desert or bare lands.
Question 43. Which type of soil is best for growing lentils?
Answer: For lentils (masoor) and other pulses, loamy soils,
which drain water easily, are required.
Question 44. Wheat are grown in the fine clayey soils. Give reason.
Answer: Crops such as wheat are grown in the fine clayey
soils, because they are rich in humus and are very fertile.
Question 45. Classify the soil on the basis of the proportion of
particles of various sizes,
Answer: On the basis of the proportion of
particles of various sizes, the soil can be classified as sandy, clayey and
loamy.
Question 46. What Is called soil moisture?
Answer: Soil holds water in it, which is called soil
moisture. The capacity of a soil to hold water is important for various crops.
Question 47. State the factors on which nature of the soil depends?
Answer: The nature of any soil depends upon the rocks from
which it has been formed and the type of vegetation that grows in it.
Question 48. What is silt?
Answer: Silt occurs as a deposit in river beds. The size of the
silt particles is between those of sand and clay.
Question 49. Explain how soil is formed.
Answer: The soil is formed by the breaking down of rocks by
the action of wind, water and climate. It is a very slow process.
Question 50. Why do air above the soil shimmer on a hot summer day?
Answer: On a hot summer day, the vapour coming out of the
soil reflects the sunlight and thus, the air above the soil seems to shimmer.
Question 51. Which type of soil is best for growing paddy?
Answer: For paddy, soils rich in clay and organic matter and
having a good capacity to
retain water are ideal.
Question 52. What is weathering?
Answer: Soil is formed by the breaking down of rocks by the
action of wind, water and climate. This process is called weathering.
Question 53. Which type of soil retains the highest amount of water
and which retains the least?
Answer: Clayey soil retains the highest amount of water and
sandy soil retains the least.
Question 54. Which natural resource supports the growth of plants by
holding the roots firmly and supplying water and nutrients?
Answer: Soil supports the growth of plants by holding the
roots firmly and supplying water and nutrients.
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