Activity 9.1 – do the activity and complete the table :
Table 9.1
| Soil source | Plants | Animals | Any other observation | |
| 1 | Garden soil | Grass, leaves flower petals grass leaves | Ant, earthworm insects. | Soft, reddish leroum. |
| 2 | Soil from the road side. | Grass | Ants, insects | Grainy plastic pieces in soil |
| 3 | Soil from the area where construction is going on | No | Insects | Reddish soil, sandy |
| 4 | Soil from the fields. | Grass | Earthworm, insects, ants. | Brownish muddy |
1. Are the soil samples collected by your friends similar to the ones collected by you?
Ans: No, the samples were different.
2. I wonder why I found pieces of plastic of plastic articles and polythene bags in the soil sample collected from the roadside and the garden.
Ans: People throw away used plastic articles and polythene bags carelessly along the roadside and elsewhere.
3. I want to know whether the soil from a field can be used to make toys?
Ans: No, it cannot be used to make toys.
Activity 9.2- Do the activity
1. Do you see layers of particles of different size in the grass tumbler.
Ans: Yes
2. Draw a diagram showing these layers.
Ans:
3. Are there some dead rotting leaves or animals remains floating in water .
Ans: Yes
9.3 – Soil type :
1. I want to know what kind of soil should be used for making matkas and surahis .
Ans: The soil used has to be clayey
9.4 – Properties of soil :
1. Boojho wondered why there was a difference in the absorption of water in the two squares.
Ans: The first square which is of tile did not absorb water because it is not porous but the kutcha road is porous and so it absorbed water.
9.5 – Moisture in Soil :
1. Have you ever passed through a farmland during a hot summer day?
Ans: On a hot summer day, the vapour coming out of the soil reflect the sunlight and the air above the soil seems to shimmer.
2. Do you see water drops any where ? If yes , where did you find them ?
Ans: Yes, water drops were seen on the inner walls of the upper part of the boiling tube.
Absorption of water by soil : ( Activity 9.6 )
1. Would you get the same results for all the samples ?
Ans: No, the results are different.
2. Which soil would have the highest percolation rate?
Ans: Sandy soil .
3. Which soil would have the lowest percolation rate?
Ans: Clayey soil .
4. Boojho heard from his neighbours that 8-10 days after the rain, the level of water in a pond or well rises. Which type of soil will allow water to reach a well faster and in greater amount?
Ans: Sandy soil.
5. Which type of soil retains the highest amount of water and which retains the least?
Ans: Clayey soil retains the highest amount of water and sandy soil retains the least.
6. Can you suggest any method to let more rain water percolate and reach the water underground ?
Ans: By making holes in the soil , the water can percolate and reach underground.
9.7 – Soil and Crops :
1. Which kind of soil would be most suitable for planting rice? Soil water should be higher or lower rate of percolation. Why ?
Ans: Clayey soil is most suitable for planting rice .Soil with lower rate of percolation because rice needs a soil that is good at retaining water.
2. Table 9.2
| Sr.No | Types of soil | Crop grow |
| 1. | Clayey | Wheat, beets , cabbage ,pea ,beans , potato . |
| 2. | Loamy | Wheat ,gram, paddy ,pulses, sugarcane, beans ,tomato, onion ,peppers, etc. |
| 3. | Sandy | Carrots, radish ,corn ,beans ,cucumber. |
3. What is the difference between rate of percolation and the amount of water retained?
Ans: Rate of percolation is the ratio of the amount of water to the percolation time whereas amount of water retained is the amount of water that is absorbed by the soil.
TEXT EXERCISE
Tick (√) the most suitable answers in questions 1 and 2 :
1. In addition to the rock particles, the soil contains _______ .
i) Air and water .
ii) Water and plants √
iii) Minerals, organic matters air and water .
iv) Water, air and plants .
2. The water holding capacity in the highest in _________ .
i) Sandy soil .
ii) Clayey soil √
iii) Loamy soil .
iv) Mixture of sand .
Answers :
i) Water and plants
ii) Clayey soil .
Match the items in column 1 with those in column 2 :
| Column 1 | Column 2 |
| i) A home for living organisms | a) Large particles |
| ii) Upper layer of the soil | b) All kind of soil |
| iii) Sandy soil | c) Dark in colour |
| iv) Middle layer of the soil | d) Small particle and packed tightly |
| v) Clayey soil | e) Lesser amount of humus |
Answers :
(i) b (ii) c (iii) a (iv) e (v) d .
1. Explain how soil is formed.
Ans: Soil is formed by the breakdown of rocks by the action of wind, water and climate.
2. How is clayey soil useful for crops?
Ans: Clayey soil are able to hold large amount of water therefore it is useful for crops as crops require water to grow.
3. List the differences between clayey soil and sandy soil.
Ans:
| Clayey soil | Sandy soil |
| i) Fine soil particle | i) Big soil particle |
| ii) Percolation rate is lower | ii) Percolation rate higher . |
| iii) Large spaces between sand particle. | iii) Little spaces between clay particle. |
4. Sketch the cross section of soil and label the various layers.
Ans:
5. Razia conducted an experiment in the field related to the rate of percolation. She observed that it took 40 mins for 200ml of water to percolate through the soil sample. Calculate the rate of percolation .
Ans: Rate of percolation (ml/mins)
= amount of water
Percolation time (min)
= 200ml
40
= 5ml/min .
6. Explain how soil pollution and soil erosion could be prevented.
Ans:
i) Soil pollution can be prevented by reducing the use of plastics ,chemical fertilizers and pesticides.
ii) Soil erosion can be prevented by stopping deforestation and planting more trees.
7. Solve the following crossword puzzle with the clues given :
Across:
2) Plantation prevents it .
5) Use should be banned to avoid soil pollution .
6) Type of soil used for making pottery .
7) Living organisms in the soil .
Down :
1) In desert soil erosion occurs through .
3) Clay and loam are suitable for cereals like.
4) This type of soil can hold very little water .
5) Collective name for layers of soil .
Answers :
Across: Down:
2) Erosion 1) Wind
5) Polythene 3) Wheat
6) Clay 4) Sandy
7) Earth worm 5) Profile .