1. Is it a good practice to remove grass and small plants that are growing in an open, unused field? Give a reason to support your answer.
2. A man digging a pit found that he could dig with ease initially but digging became difficult as he went deeper. He could not dig beyond a depth of 5 feet. Provide a suitable scientific explanation.
3.Rajasthan is a desert state in India. Once while travelling to Rajasthan by train, Boojho observed several streams and rivulets of rainwater during the journey but to his surprise, he did not see streams of water in the desert region even during rains. Help Boojho find a suitable explanation for this.
4.Why is soil erosion relatively less in dense forests as compared to barren, open fields?
Ans 1. No, It is not a good practice because plants cover the soil surface and their roots bind the soil particles to hold them firmly. This prevents washout of the top layer of soil from strong winds and rains.
Ans 2. The top layer of soil is loose and easy to dig, as we down deep soil consists of weathered rocks or which makes digging difficult.
Ans 3. Deserts are filled with stretches of sand. When rain falls rainwater percolates immediately. Hence water streams are not found in deserts.
Ans 4. In dense forests, the tree cover (canopy) prevents rainwater from directly falling on the ground/soil. Also, roots of the vegetation bind the soil particles and hold them together. As a result soil erosion is minimised.
But in barren, open fields the soil is exposed to the falling rain. The soil particles become loose due to the impact of raindrops and the flow of water carries them away. The flowing water further erodes the soil surface aggravating erosion.
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