Soil Erosion MCQ | PDF - Free Printable

Here is the complete solution to the worksheet “Soil Erosion and Conservation” for Grade V, with clear explanations for each answer.

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1. Fill in the blanks.

a. Cutting down of trees on large scale is called _deforestation_.
→ *Explanation:* Deforestation refers to the large-scale removal of forests, often for agriculture, logging, or urban development. It’s a major cause of soil erosion because tree roots help hold soil in place.

b. _Humus_ is the organic matter made of dead plants and animals.
→ *Explanation:* Humus is the dark, nutrient-rich material formed when plant and animal matter decays in the soil. It improves soil structure and fertility.

c. By growing _trees_ or _grass_ is the most effective method to prevent soil from erosion.
→ *Explanation:* Plant roots bind the soil together, reducing the impact of wind and water that can wash or blow soil away. Trees and grasses are especially effective because they cover the ground and anchor the soil.

d. The breaking of rocks into smaller pieces is called _weathering_.
→ *Explanation:* Weathering is the natural process where rocks break down into smaller fragments due to physical (like freeze-thaw), chemical (like acid rain), or biological (like plant roots) forces — not to be confused with erosion, which moves the broken material.

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2. Tick (√) the correct word.

a. Soil that contains humus is called (topsoil / loam).
→ *Correct: topsoil*
→ *Explanation:* Topsoil is the uppermost layer of soil and is rich in humus and nutrients. Loam is a type of soil texture (mixture of sand, silt, and clay), not defined by humus content alone.

b. It takes about 200 to 400 years for the formation of just 1 cm of (rock / soil).
→ *Correct: soil*
→ *Explanation:* Soil formation is an extremely slow process involving weathering of rock, accumulation of organic matter, and microbial activity over centuries.

c. Farming on slopes is called (step farming / ladder farming).
→ *Correct: step farming*
→ *Explanation:* Step farming (also called terracing) involves creating flat steps on hillsides to reduce runoff and soil loss. “Ladder farming” is not a real term.

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3. Define.

a. Soil erosion
→ *Definition:* Soil erosion is the process by which topsoil is removed from the land surface by natural agents like wind, water, or ice, often accelerated by human activities like deforestation or overgrazing.

b. Conservation
→ *Definition:* Conservation means protecting and preserving natural resources (like soil, water, forests) so they can be used sustainably by future generations. In this context, it refers to practices that prevent soil loss.

c. Weathering
→ *Definition:* Weathering is the breakdown of rocks and minerals at Earth’s surface through physical, chemical, or biological processes — without movement of the material.

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4. Answer the following in one or two sentences.

a. Name the agents of soil erosion.
→ *Answer:* The main agents of soil erosion are water (rainfall, rivers), wind, and ice (glaciers). Human activities like deforestation and overgrazing also accelerate erosion.

b. What are afforestation?
→ *Answer:* Afforestation is the process of planting trees in an area where there were no trees before. It helps prevent soil erosion, improve air quality, and restore ecosystems.

c. Why is grass grown on land after crop production?
→ *Answer:* Grass is grown to protect the soil from erosion during fallow periods. Its root system holds the soil together, prevents nutrient loss, and improves soil health for future crops.

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5. Answer the following questions in brief.

a. Explain the three layers of soil using a well labelled diagram.
*(Since we can’t draw here, I’ll describe it clearly for you to sketch.)*

> Diagram Description:
>
> Draw a vertical cross-section of soil with 3 distinct horizontal layers:
>
> - Topsoil (A Horizon): Top layer — dark, rich in humus and nutrients. Labeled “Topsoil — Rich in Organic Matter.”
> - Subsoil (B Horizon): Middle layer — lighter color, contains clay, iron, and minerals washed down from above. Labeled “Subsoil — Minerals & Clay.”
> - Parent Rock (C Horizon): Bottom layer — partially weathered rock, little organic matter. Labeled “Parent Rock — Weathered Bedrock.”
>
> *(Optional: Add a small drawing of grass/plants rooted in the topsoil to show its importance.)*

b. What are the steps one should take to control soil erosion? (Any three)
→ *Answer:*
1. Plant trees and grasses – their roots hold soil firmly.
2. Use terrace farming on slopes – reduces water runoff.
3. Practice crop rotation and cover cropping – keeps soil covered and fertile year-round.

c. What do you mean by erosion due to human activities? Explain.
→ *Answer:* Erosion due to human activities means soil loss caused by actions like cutting down forests (deforestation), overgrazing by animals, improper farming techniques, or construction. These activities remove protective vegetation and expose soil to wind and water, speeding up erosion beyond natural rates.

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✔ Final Tip for Students: Always remember — healthy soil = healthy food = healthy planet. Protecting soil is part of protecting our future!

Let me know if you’d like a printable version or flashcards for revision!