Soil as a Resource – Class 10 Long Answer Questions and Answers
Medium (Application & Explanation)
1. Why is soil called a non-renewable resource? How does this affect agriculture?
Answer:
- Soil forms very slowly. It takes thousands of years to build a thin layer.
- Fast erosion can remove soil in a few years. Formation cannot keep up.
- Loss of topsoil reduces fertility. Crop yields fall.
- Farmers must use conservation methods like bunds and contour ploughing.
- They should add organic matter and avoid overuse of chemical fertilizers.
- Sustainable use keeps soil healthy, and agriculture remains productive.
2. Compare Alluvial soil and Black soil based on formation, features, and crops.
Answer:
- Formation: Alluvial is by rivers (silt, sand, clay). Black is from basalt weathering.
- Texture: Alluvial is loamy and easy to work. Black is clayey and sticky.
- Water: Alluvial has good drainage. Black has high water-holding.
- Behavior: Black swells when wet and cracks when dry. Alluvial stays stable.
- Regions: Alluvial in Indo-Gangetic plains and deltas. Black in Deccan Plateau.
- Crops: Alluvial suits rice, wheat, sugarcane. Black suits cotton, soybean, groundnut.
3. Explain how Laterite soil forms. Why is it hard for farming? How can it be used?
Answer:
- Laterite forms in high temperature and heavy rainfall areas.
- Leaching removes soluble nutrients. Iron and aluminium remain.
- Soil becomes acidic, sandy, and low in nutrients.
- When exposed to air, it becomes hard and compact.
- Farming needs fertilizers, manure, and liming to reduce acidity.
- It supports tea, coffee, cashew with inputs. It is also a building material.
4. What are the main features of Red and Yellow soils? How can farmers improve them?
Answer:
- They form from crystalline rocks under heat and humidity.
- Color comes from iron. More oxidation gives red; hydrated forms look yellow.
- They are sandy to loamy, often low in fertility.
- They can be acidic and lack nitrogen and humus.
- Farmers can add organic manure, NPK fertilizers, and do liming.
- Use mulching and irrigation to save moisture and improve yield.
5. Describe Arid soils and explain how irrigation changes their use.
Answer:
- Arid soils form in dry regions with low rainfall.
- They are sandy, light, and have low organic matter.
- Salts accumulate due to evaporation, causing salinity.
- Natural fertility is low; farming is hard without water.
- With irrigation, we can grow cotton, wheat, barley.
- Use drip irrigation, salt leaching, and windbreaks to improve soil.
High Complexity (Analysis & Scenario-based)
6. A farmer in Maharashtra grows cotton on Black soil. It cracks in summer and waterlogs in monsoon. Suggest a full plan.
Answer:
- Use mulching to reduce cracking and save moisture.
- Build contour bunds and farm ponds to slow runoff.
- Provide surface drains or broad beds and furrows to avoid waterlogging.
- Add organic matter to improve structure and reduce hard setting.
- Choose short-duration or drought-tolerant cotton varieties.
- Use intercropping with pulses to improve soil nitrogen and spread risk.
7. You manage an alluvial farm in the Indo-Gangetic plains. Create a sustainable cropping and water plan for one year.
Answer:
- Adopt a rice–wheat rotation with a pulse (moong/masoor) as a third crop.
- Include vegetables on small plots for cash and nutrient use.
- Use laser levelling to save water and improve uniform irrigation.
- For rice, use alternate wetting and drying (AWD) to save water.
- Harvest rainwater through field bunds and check-bunds.
- Add green manure and crop residues to keep soil fertile.
8. In a hill region with Forest soils and heavy rain, villagers want farming without harming forests. What is your plan?
Answer:
- Do terrace farming to reduce erosion and manage water.
- Practice agroforestry: mix trees with crops for stability and income.
- Use contour farming and grass strips to slow runoff.
- Grow native crops like millets, buckwheat, pulses that suit slopes.
- Apply mulch and compost to build humus in forest soils.
- Build check-dams and stone bunds to recharge and prevent landslides.
9. Climate change brings intense rain and long dry spells. Predict soil impacts and give soil-specific solutions.
Answer:
- Alluvial: Flooding and erosion risk. Build embankments, plant cover crops.
- Black: More cracking in drought; waterlogging in bursts. Use mulch, drainage.
- Red/Yellow: Faster nutrient loss. Add organic matter and do mulching.
- Laterite: Strong leaching and acidity. Use liming and balanced fertilizers.
- Arid: Rising salinity. Do drip irrigation, salt leaching, and salt-tolerant crops.
- Forest: Landslide risk. Maintain vegetation cover and terraces.
10. The government wants to boost oilseeds. Which soils and crops will you target? What inputs are needed?
Answer:
- Black soils: Target groundnut and soybean. Use gypsum for pod fill; ensure drainage.
- Red/Yellow soils: Grow groundnut and sesame. Add manure, NPK, and liming.
- Alluvial soils: Promote mustard and sesame in winter. Use balanced nutrients.
- Arid irrigated zones: Support mustard with drip and salt management.
- Provide soil testing, micro-nutrients (like Zn, B), and quality seeds.
- Train farmers in water-saving and pest management for higher yields.