Soil quiz

The uppermost layer of soil is the:

The decaying organic matter in soil is called:

Which soil has the highest water holding capacity?

The soil best for most plants is:

Breaking down of rocks by wind, water and climate is called:

Percolation rate is measured in:

Paddy grows best in:

Soil erosion can be reduced by:

Sandy soil has:

The layer below the C-horizon is:

Why is the A-horizon dark in colour? (2 marks)

Why does water drain quickly through sandy soil? (2 marks)

Name two crops grown in clayey and loamy soils. (2 marks)

How do earthworms improve soil? (2 marks)

Why is clay used to make pots and bricks? (2 marks)

What is loam? (2 marks)

How do plant roots help prevent soil erosion? (2 marks)

Why is the soil of a desert sandy? (2 marks)

What is the composition of the C-horizon? (2 marks)

How does soil help in the water cycle? (2 marks)

The percolation rate of a soil is 6 mL/min. How long will it take for 300 mL of water to percolate? (3 marks)

Three soil samples allowed 200 mL of water to pass in 10 min (P), 25 min (Q) and 50 min (R). Find the percolation rate of each and identify the sandy and clayey samples. (3 marks)

A soil sample weighed 250 g before drying and 225 g after drying. Find the percentage of water in the soil. (3 marks)

100 mL of water was poured on soil in a funnel. 70 mL was collected from sample A and 40 mL from sample B. How much water did each absorb? Which soil holds more water? (3 marks)

India loses an estimated 5000 million tonnes of topsoil every year to erosion. If 30 percent of this is lost due to wind, how many million tonnes are lost due to wind and how many due to other agents? (3 marks)

Read the passage and answer the questions. A farmer in Punjab grows wheat in loamy soil, while a farmer in West Bengal grows paddy in soil that holds water well. (i) Why is loamy soil good for wheat? (ii) What kind of soil is used for paddy? (iii) Why must paddy fields hold water? (5 marks)

Read the passage and answer the questions. Paheli dug a pit near a construction site and saw dark soil at the top, lighter and harder soil below, and rocky pieces further down. (i) Name the top layer. (ii) Name the middle layer. (iii) Name the layer with rock pieces. (5 marks)

Read the passage and answer the questions. After heavy rain on a bare hillside, muddy water flowed down and deep channels formed in the soil. (i) What process is this? (ii) Why was the hillside more affected? (iii) Suggest two methods to prevent it. (5 marks)

Read the passage and answer the questions. Boojho heated some dry-looking soil in a test tube and saw water droplets on the cooler upper part of the tube. (i) Where did the droplets come from? (ii) What does this show about soil? (iii) Why is soil moisture important for plants? (5 marks)

Read the passage and answer the questions. A field near a factory had oily waste and plastic dumped on it. Crops stopped growing well. (i) What is this pollution called? (ii) How does plastic affect soil? (iii) Suggest two remedies. (5 marks)

Draw a labelled soil profile and describe each horizon. (6 marks)

Describe an activity to find the percolation rate of a soil sample. Draw the set-up and show a sample calculation. (6 marks)

Compare sandy, clayey and loamy soils on five points and give the crops suited to each. (6 marks)

Explain the causes and effects of soil erosion and four methods of soil conservation, with a diagram of terrace farming. (6 marks)

Describe an activity to show that soil contains air and water and how to compare the water absorption of two soils. Draw the set-ups. (6 marks)