Soil Resources ICSE Class 10: Soil Types, Erosion and Conservation

What Soil Resources is about

Weightage: CISCE publishes no chapter weightage. Each Part II chapter is one of nine 10-mark questions (2 + 2 + 3 + 3), of which you answer any five; the chapter can also appear in the Part I MCQs and the map of India question.Source: CISCE ICSE 2027 Specimen Question Paper 502, Geography (H.C.G. Paper 2)

Key concepts

Alluvial soil

Formation: deposited by rivers (and by the sea along the coasts) from material eroded in their upper courses.
Distribution: the northern plains from Punjab to West Bengal and Assam, the deltas of the Mahanadi, Godavari, Krishna and Cauvery, and the coastal plains.
Composition: rich in potash and lime; poor in nitrogen, phosphorus and humus.
Characteristics: light grey to dark in colour; texture from sandy to clayey loam; porous; very fertile and easy to plough.
Khadar and bhangar: khadar is new alluvium deposited every year by floods in the low-lying flood plains; it is fine, lighter in colour and more fertile. Bhangar is old alluvium on the higher land above flood level; it is coarser, darker, contains lime nodules (kankar) and is less fertile. Near the hills, in a river's upper course, alluvium is coarser; in the lower course and deltas it is finer and clayey.
Crops: rice, wheat, sugarcane, jute, pulses and oilseeds.

Worked example

(2 marks) Distinguish between khadar and bhangar.

Try it first, then show the solutionSolution

1. Khadar is new alluvium deposited every year by floods in the low-lying flood plains; it is fine and more fertile - 1 mark.
2. Bhangar is old alluvium found on higher land above flood level; it is coarser, has lime nodules (kankar) and is less fertile - 1 mark.

Answer: Khadar is new, fine alluvium renewed each year by floods in the flood plains and is very fertile. Bhangar is old alluvium on higher ground beyond the reach of floods; it is coarser, contains kankar and is less fertile.

Black soil (regur)

Formation: by the weathering of basaltic lava rocks of the Deccan trap (in place, not transported).
Distribution: Maharashtra, Gujarat (Saurashtra), western Madhya Pradesh, and parts of Karnataka, Telangana and Andhra Pradesh: the north-western Deccan.
Composition: rich in iron, lime, calcium, magnesium, potash and alumina; poor in nitrogen, phosphorus and organic matter.
Characteristics: black in colour (because of compounds of iron and aluminium, such as titaniferous magnetite); very fine, clayey texture; high moisture-retentive capacity; becomes sticky when wet and develops deep cracks when dry, which lets air into the soil ('self-ploughing').
Crops: cotton (hence 'black cotton soil'), sugarcane, wheat, jowar, groundnut and tobacco.

Why it suits cotton: it holds moisture for a long time, which cotton needs in its long growing season; it is rich in lime, potash and calcium; and its deep cracks aerate the soil.

Worked example

(2 marks) Why is black soil suitable for growing cotton? Give two reasons.

Try it first, then show the solutionSolution

1. Its fine clayey texture retains moisture for a long time, which cotton needs - 1 mark.
2. It is rich in lime, potash and calcium, and its cracks in the dry season aerate the soil - 1 mark.

Answer: Black soil retains moisture for long periods because of its clayey texture, and it is rich in lime, potash and calcium; its deep dry-season cracks also aerate the soil. These conditions suit cotton.

Red soil

Formation: by the weathering of ancient crystalline and metamorphic rocks such as granite and gneiss, in areas of low to moderate rainfall.
Distribution: Tamil Nadu, Karnataka, Andhra Pradesh, Telangana, Odisha, Chhattisgarh, Jharkhand and eastern Madhya Pradesh: the eastern and southern Deccan.
Composition: rich in iron and potash; poor in nitrogen, phosphorus, lime and humus.
Characteristics: red because of iron oxide spread through the rock; yellow where it is hydrated; sandy to loamy texture; porous and friable, so it does not hold water well; generally less fertile.
Crops: millets, pulses, groundnut, tobacco and potatoes; with irrigation and fertilisers, rice, wheat and cotton.

Note: red soil's poor water retention is due to its coarse, porous texture, not to its iron oxide content (which only gives it its colour).

Worked example

(2 marks) Give a geographical reason: red soil has a poor water-retaining capacity. Why is it red?

Try it first, then show the solutionSolution

1. It is coarse, sandy-loamy and porous, so water drains through quickly - 1 mark.
2. It is red because iron oxide is spread through the parent rock and soil - 1 mark.

Answer: Red soil drains quickly because its texture is coarse and porous. Its red colour comes from iron oxide diffused through it; the colour has nothing to do with its poor water retention.

Laterite soil

Formation: in areas of high temperature and heavy rainfall with alternating wet and dry seasons. Heavy rain leaches (washes down) the silica and lime from the top layer, leaving behind oxides of iron and aluminium. The word comes from the Latin 'later', meaning brick.
Distribution: on the summits of the Western Ghats and Eastern Ghats, the Rajmahal hills, the Vindhyas and Satpuras, and in hilly parts of Karnataka, Kerala, Tamil Nadu, Odisha, Assam and Meghalaya. (When asked for regions, name the hill summits rather than states.)
Composition: rich in iron and aluminium oxides; poor in nitrogen, potash, lime and organic matter.
Characteristics: reddish brown; coarse and porous; hardens on exposure to air, so it is used to make bricks; acidic and infertile.
Crops: with heavy manuring (and lime and nitrogen fertilisers), tea, coffee, rubber, cashew and coconut.

To improve its productivity, add manure and fertilisers rich in nitrogen, and lime to reduce acidity.

Worked example

(3 marks) Explain how laterite soil is formed, why it is infertile, and what can be done to make it productive.

Try it first, then show the solutionSolution

1. Formation: high temperature and heavy rainfall with alternating wet and dry seasons cause leaching; silica and lime are washed away, leaving iron and aluminium oxides - 1 mark.
2. Infertile: leaching removes plant nutrients such as nitrogen, potash and lime, and the soil is acidic and poor in humus - 1 mark.
3. Improvement: add manure, nitrogen-rich fertilisers and lime - 1 mark.

Answer: Laterite forms where heavy rain and high temperature leach away silica and lime, leaving iron and aluminium oxides. Leaching also removes nutrients and humus, so it is acidic and infertile. Manure, nitrogenous fertilisers and lime make it productive for crops like tea, coffee and cashew.

Soil erosion: meaning, agents and causes

Meaning: soil erosion is the removal of the top, fertile layer of soil by natural agents, often speeded up by human activities.

Agents (the forces that carry soil away):

• Running water: sheet erosion (a thin layer removed evenly), rill erosion (small channels) and gully erosion (deep channels that make land unfit for farming, as in the Chambal ravines).
• Wind: blows away loose, dry soil in arid areas such as Rajasthan.
• Also glaciers in mountains and sea waves along coasts.

Causes (what makes erosion happen faster):

• Deforestation: removing trees exposes soil to rain and wind.
• Overgrazing: animals remove the grass cover.
• Faulty methods of farming: ploughing up and down slopes, leaving fields bare.
• Heavy rainfall and floods on slopes.
• Mining, quarrying and construction.

A question asking for causes needs human or natural activities such as deforestation; a question asking for agents needs water, wind and so on.

Worked example

(2 marks) What is meant by soil erosion? Name two agents of soil erosion.

Try it first, then show the solutionSolution

1. Soil erosion is the removal of the fertile top layer of soil - 1 mark.
2. Agents: running water and wind - 1 mark.

Answer: Soil erosion is the washing or blowing away of the fertile top layer of soil. Its two main agents are running water and wind.

Soil conservation: importance and methods

Importance: soil is the basis of agriculture and food production; it forms very slowly and cannot easily be replaced; eroded soil silts up rivers and reservoirs, increasing floods; loss of soil reduces crop yields and threatens food security.

Methods:

• Afforestation and reforestation: trees hold soil with their roots and break the force of rain.
• Contour ploughing: ploughing across the slope along contour lines, so furrows hold water and soil.
• Terrace farming: cutting the hill slope into flat steps; each step holds water and soil.
• Strip cropping: growing strips of grass between strips of crops to check wind and water.
• Shelter belts: rows of trees planted to break the force of wind in dry areas.
• Plugging gullies and building check dams.
• Controlling grazing and shifting cultivation.
• Crop rotation and mulching to keep the soil covered and fertile.

Methods suited to hilly areas: terrace farming, contour ploughing and afforestation of slopes. Shelter belts are for windy, dry plains, not hills.

Worked example

(3 marks) Mention two causes of soil erosion in India and one soil conservation method suitable for a hilly area.

Try it first, then show the solutionSolution

1. Cause: deforestation exposes soil to rain and wind - 1 mark.
2. Cause: overgrazing removes the grass cover (or faulty farming methods) - 1 mark.
3. Hilly-area method: terrace farming, cutting slopes into steps to hold soil and water (or contour ploughing) - 1 mark.

Answer: Two causes are deforestation and overgrazing, which remove the plant cover protecting the soil. In hilly areas, terrace farming (cutting slopes into level steps) checks soil erosion.

Soil Resources in real life

Each concept, met in an everyday situation. Read the situation, answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Topics in this chapter

• Types of Soil in India: Alluvial, Black, Red and Laterite
• Soil Erosion: Agents, Causes and Soil Conservation Methods

Soil Resources: key facts

Alluvial

River deposits; rich in potash, lime; poor in N, P; rice, wheat, sugarcane, jute

Khadar new and fertile; bhangar old with kankar.

Black

Weathering of Deccan lava; rich in iron, lime, calcium, magnesium, potash; clayey; moisture-retentive; cotton

Self-ploughing cracks.

Red

Weathering of granite and gneiss; iron oxide gives colour; porous; millets, pulses, groundnut

Poor water retention from coarse texture.

Laterite

Leaching under heavy rain and high temperature; iron and aluminium oxides; infertile; tea, coffee, cashew with manure

Hardens like brick.

Agents of erosion

Running water (sheet, rill, gully), wind, glaciers, waves

Hill conservation

Terrace farming, contour ploughing, afforestation

Shelter belts are for dry plains.

Soil Resources: map work

The places on the official CISCE map list for this chapter. Find each one on an outline map of India and practise marking it.

How the board asks Soil Resources

The question patterns to expect, and the method that works for each.

Tricks to remember Soil Resources

Short memory aids. Say each one aloud once, then use it on a question the same day.

• A-B-R-L by origin

  Alluvial = Rivers bring; Black = Basalt breaks; Red = Rock (granite) rusts; Laterite = Leaching.

  Use it when: Formation.

• Khadar is Kid, Bhangar is Big brother

  Khadar is new (young) and fertile; bhangar is old and has kankar.

  Use it when: Khadar versus bhangar.

• Agents versus causes

  Agents are 'who carries' (water, wind); causes are 'why faster' (deforestation, overgrazing).

  Use it when: Erosion questions.

Soil Resources: board-level solved questions

Ordered from board level to HOTS. Cover the solution, write your own, then compare step by step.

Case-study practice (Section B style)

Read the situation, then answer every part. In the board paper this is a 10-mark question split into 2 + 2 + 3 + 3 marks.

Where the marks are

How a typical answer is split into step marks. Show every step: a right final answer alone rarely earns full marks.

Where students lose marks in Soil Resources

The slips examiners see most often, and what to write instead.

• ✗Mistake: Saying 'black soil is fertile' without the reason

  CISCE examiners' comments, 2024: candidates only said black soil is fertile without explaining why it suits cotton.

  ✓Do this: Give properties: moisture retention, lime, potash, calcium, aeration.

  Usually costs: 1 to 2 marks.

• ✗Mistake: Reversing khadar and bhangar, or giving examples as differences

  CISCE examiners' comments, 2024: candidates reversed khadar and bhangar and gave soil examples instead of differences.

  ✓Do this: Khadar = new, fertile flood plain; bhangar = old, higher, kankar.

  Usually costs: 1 mark.

• ✗Mistake: Incomplete laterite answers

  CISCE examiners' comments, 2024: candidates gave only 'high temperature' or 'high rainfall' without explaining leaching, wrote crops instead of what to add, and wrote states instead of regions.

  ✓Do this: Explain leaching; to improve, add manure, nitrogen fertilisers and lime; regions = hill summits.

  Usually costs: Up to 3 marks.

• ✗Mistake: Agents for causes, wrong hill method

  CISCE examiners' comments, 2024 and 2025: candidates named agents instead of causes, gave causes in place of agents, and gave shelter belts or government schemes as a hill method.

  ✓Do this: Agents = water, wind; causes = deforestation, overgrazing; hills = terracing, contour ploughing.

  Usually costs: 1 to 2 marks.

• ✗Mistake: Wrong formation or reason for red soil

  CISCE examiners' comments, 2025: candidates said black soil forms by denudation of lava rocks instead of weathering, and cited iron oxide for red soil's poor water retention instead of porous, coarse texture.

  ✓Do this: Black = weathering of lava; red's drainage = coarse, porous texture.

  Usually costs: 1 mark each.

Practice questions on Soil Resources

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

1. Q1 · 1 mark · MCQBoard level

   Black soil is formed from:
   (a) river deposits
   (b) weathering of lava rocks
   (c) leaching of granite
   (d) wind-blown sand

   Hint

   Deccan trap.

   Answer

   (b) weathering of lava rocks.

2. Q2 · 1 mark · MCQBoard level

   Which soil is used to make bricks because it hardens on exposure to air?
   (a) Alluvial
   (b) Black
   (c) Red
   (d) Laterite

   Hint

   Latin 'later'.

   Answer

   (d) Laterite.

3. Q3 · 2 marks · Very short answerHarder board level

   Name two crops grown on red soil and explain why irrigation helps.

   Hint

   Porous soil.

   Answer

   Millets and groundnut (also pulses, tobacco). Because red soil is porous and drains water quickly, irrigation supplies the moisture crops need, allowing even rice and wheat to be grown.

4. Q4 · 2 marks · Very short answerBoard level

   Distinguish between gully erosion and sheet erosion.

   Hint

   Depth of removal.

   Answer

   Sheet erosion removes a thin layer of topsoil evenly over a large area by running water; gully erosion cuts deep channels (gullies or ravines) that make land unfit for cultivation.

5. Q5 · 2 marks · Very short answerHOTS / competency

   Why is alluvial soil in the lower course and delta of a river finer than in its upper course?

   Hint

   Speed of the river.

   Answer

   In the upper course the river flows fast and drops only coarse material near the hills; as it slows down in the lower course and delta, it deposits fine silt and clay, so the soil there is finer and more fertile.

6. Q6 · 3 marks · Short answerBoard level

   State three importance of soil conservation.

   Hint

   Agriculture, time, floods.

   Answer

   (1) Soil is the basis of agriculture and food supply. (2) It takes hundreds of years to form and cannot be replaced quickly. (3) Eroded soil silts rivers and reservoirs, increasing floods and reducing their capacity.

7. Q7 · 3 marks · Short answerHarder board level

   Explain how shelter belts and strip cropping reduce erosion, and where each is useful.

   Hint

   Wind and water.

   Answer

   Shelter belts are rows of trees that break the force of wind, protecting soil in dry, windy plains like Rajasthan. Strip cropping grows strips of grass between crops; the grass checks the speed of wind and running water, reducing erosion on gentle slopes and plains.

8. Q8 · 3 marks · Short answerHOTS / competency

   Compare black soil and red soil on formation, colour reason, water retention and two crops.

   Hint

   Basalt versus granite.

   Answer

   Black: from weathered basalt; dark from iron and aluminium compounds; clayey and highly moisture-retentive; cotton and sugarcane. Red: from weathered granite and gneiss; red from iron oxide; porous with poor retention; millets and groundnut.

9. Q9 · 2 marks · Very short answerHarder board level

   Name two regions (not states) where laterite soil is found.

   Hint

   Hill summits.

   Answer

   The summits of the Western Ghats and of the Eastern Ghats (also the Rajmahal hills, the Vindhyas and Satpuras).

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1. 1.Which soil is called regur?Show answer

   Black soil.

2. 2.What gives red soil its colour?Show answer

   Iron oxide.

3. 3.What is kankar?Show answer

   Lime nodules found in old alluvium (bhangar).

4. 4.Which process forms laterite?Show answer

   Leaching.

5. 5.Name one conservation method for hills.Show answer

   Terrace farming (or contour ploughing).

6. 6.Which soil is best for cotton?Show answer

   Black soil.

Quick revision checklist

The night before the exam: can you do each of these without looking?

• ☐Alluvial: river deposits; potash, lime; northern plains and deltas; rice, wheat, sugarcane, jute.
• ☐Khadar new and fertile; bhangar old with kankar.
• ☐Black: weathered lava; clayey, moisture-retentive, self-ploughing; cotton.
• ☐Red: weathered granite; iron oxide colour; porous; millets, groundnut.
• ☐Laterite: leaching; iron and aluminium oxides; infertile; bricks; tea, coffee, cashew with manure.
• ☐Erosion: agents water and wind; causes deforestation, overgrazing, faulty farming.
• ☐Conservation: afforestation, contour ploughing, terracing, strip cropping, shelter belts, check dams.

Soil Resources: frequently asked questions