Indian Geography: Soils and Mineral Resources

Indian Soils and Mineral Resources are frequently tested in Kerala PSC Geography sections. Questions cover soil types, their characteristics, distribution, and major minerals with their mining locations. Based on NCERT Class 10 Geography (Contemporary India II) and Class 12.

Major Soil Types of India

India has six major soil types, classified by the Indian Council of Agricultural Research (ICAR).

Soil Type	Also Called	Colour	Key Characteristics
Alluvial Soil	Riverine soil	Light grey to ash	Most widespread; deposited by rivers; fertile; rich in potash, poor in nitrogen and phosphorus
Black Soil	Regur soil / Cotton soil	Black to dark grey	Formed from Deccan basalt (lava); self-ploughing (swells when wet, cracks when dry); rich in calcium, magnesium, iron; poor in nitrogen, phosphorus, organic matter
Red Soil	—	Red to yellow	Red colour from iron oxide; formed from crystalline igneous rocks; poor in nitrogen, phosphorus, humus
Laterite Soil	—	Brick red	Formed by leaching in heavy rainfall areas; rich in iron and aluminium; poor in nitrogen, potassium, calcium; acidic
Desert/Arid Soil	Sandy soil	Sandy, pale brown	Sandy texture; poor in humus and moisture; rich in phosphate; high salt content; low fertility
Mountain/Forest Soil	—	Dark brown to black	Found in hilly regions; rich in humus (upper slopes); acidic; varies with altitude

Detailed Distribution of Soils

Soil Type	Major Regions	Suitable Crops
Alluvial	Indo-Gangetic plain, Brahmaputra valley, coastal plains, deltas (Punjab to Assam; UP, Bihar, West Bengal, Tamil Nadu coast)	Rice, wheat, sugarcane, jute
Black	Maharashtra, Madhya Pradesh, Gujarat, parts of Andhra Pradesh, Karnataka, Tamil Nadu (Deccan Plateau — formed from Deccan Trap basalt)	Cotton (best suited), soybean, jowar, wheat, sugarcane
Red	Tamil Nadu, Karnataka, Andhra Pradesh, Odisha, Jharkhand, Chhattisgarh, parts of Rajasthan (eastern and southern Deccan Plateau)	Groundnut, millets, tobacco, pulses
Laterite	Kerala, Karnataka (coast), Tamil Nadu hills, Odisha, Assam hills, Meghalaya	Tea, coffee, cashew, rubber, coconut
Desert	Western Rajasthan (Thar Desert), parts of Gujarat, Haryana	Bajra (with irrigation: wheat, cotton)
Mountain	Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Northeast hills, Western Ghats higher elevations	Tea (Darjeeling), spices, temperate fruits

Alluvial Soil Sub-types

Type	Description
Khadar	Newer alluvium; found in flood plains; more fertile; renewed every year
Bhangar	Older alluvium; found on higher terraces; contains kankar (lime nodules); less fertile than Khadar

Soil Conservation Methods

Method	Description
Contour ploughing	Ploughing along contour lines on slopes to reduce water runoff
Terrace farming	Step-like flat areas cut on hillsides (common in Himalayas, Western Ghats)
Strip cropping	Alternating strips of crops with grass/cover
Shelter belts	Rows of trees planted to break wind (used in desert areas)
Mulching	Covering soil with organic material to retain moisture
Afforestation	Planting trees to bind soil and prevent erosion
Check dams / Bunds	Small barriers across streams to slow water and trap soil

Mineral Resources of India

Minerals are classified into three main categories:

Category	Types	Examples
Metallic — Ferrous	Contain iron	Iron ore, manganese, chromite, nickel, cobalt
Metallic — Non-ferrous	Do not contain iron	Copper, gold, silver, lead, zinc, bauxite (aluminium ore), tin
Non-metallic	Non-metals	Mica, limestone, gypsum, salt, dolomite, phosphate
Energy minerals	Fuel sources	Coal, petroleum, natural gas, uranium, thorium

Major Metallic Minerals

Mineral	Rank/Production	Major States	Key Mines
Iron Ore	India is 4th largest producer globally	Odisha (largest), Jharkhand, Chhattisgarh, Karnataka, Goa	Bailadila (Chhattisgarh), Singhbhum (Jharkhand), Mayurbhanj (Odisha), Bellary-Hospet (Karnataka)
Manganese	Used in steel making	Odisha, Maharashtra, Madhya Pradesh, Karnataka	Nagpur-Bhandara (Maharashtra), Koraput (Odisha)
Bauxite	Aluminium ore	Odisha, Gujarat, Jharkhand, Maharashtra, Chhattisgarh	Amarkantak (MP-Chhattisgarh), Panchpatmali (Odisha — largest deposit)
Copper	Electrical industry	Rajasthan (largest), Jharkhand, Madhya Pradesh	Khetri (Rajasthan), Singhbhum (Jharkhand), Malanjkhand (MP)
Gold	Precious metal	Karnataka (95% of India’s gold)	Kolar Gold Fields (nearly exhausted), Hutti Gold Mines (Raichur)
Chromite	Used in stainless steel	Odisha (over 95%)	Sukinda Valley (Odisha — one of world’s largest)

Non-Metallic Minerals

Mineral	Use	Major States
Mica	Electrical insulation	Jharkhand (Koderma — “Mica capital”), Bihar, Rajasthan, Andhra Pradesh
Limestone	Cement industry	Rajasthan, Madhya Pradesh, Andhra Pradesh, Gujarat, Karnataka
Gypsum	Cement, fertiliser, plaster of Paris	Rajasthan (over 80% — Bikaner, Jaisalmer), Jammu and Kashmir
Dolomite	Steel, glass making	Odisha, Madhya Pradesh, Chhattisgarh

Energy Minerals

Mineral	Major States/Regions	Key Facts
Coal	Jharkhand (Jharia — largest coalfield), West Bengal (Raniganj — oldest), Odisha, Chhattisgarh, Madhya Pradesh	India has 5th largest reserves globally; mainly Gondwana coal (250 million years old)
Petroleum	Mumbai High (offshore — largest), Assam (Digboi — oldest oil field in India, 1889), Gujarat (Ankleshwar), Rajasthan (Barmer), KG Basin (Andhra Pradesh)	ONGC and OIL are major public sector explorers
Natural Gas	KG Basin (largest), Mumbai High, Gujarat, Rajasthan, Tripura	Used for power, fertiliser, CNG
Uranium	Jharkhand (Jaduguda — India’s first uranium mine), Andhra Pradesh, Meghalaya, Rajasthan	Used in nuclear power
Thorium	Kerala (monazite sands in coastal areas — richest source globally), Tamil Nadu, Odisha	India has world’s largest thorium reserves

Coal Types (by carbon content)

Type	Carbon %	Quality	Found In
Anthracite	80-95%	Highest quality; hard; rare in India	Jammu and Kashmir (small deposits)
Bituminous	60-80%	Most commonly used; good for metallurgy	Jharkhand, West Bengal, Odisha
Lignite	40-55%	Brown coal; low grade	Tamil Nadu (Neyveli — largest lignite mine), Rajasthan, Gujarat
Peat	Below 40%	Lowest grade; high moisture	Limited deposits

Mineral Belts of India

Belt	Region	Key Minerals
North-Eastern Plateau Belt	Chotanagpur Plateau (Jharkhand, Odisha, West Bengal, Chhattisgarh)	Iron ore, coal, manganese, bauxite, mica, copper
South-Western Plateau Belt	Karnataka, Goa, Kerala (Western Ghats)	Iron ore, manganese, gold, bauxite, monazite
North-Western Belt	Rajasthan, Gujarat	Copper, gypsum, marble, salt, limestone, petroleum
Southern Belt	Tamil Nadu, Andhra Pradesh, Kerala	Lignite, thorium, mica, limestone

Kerala-Specific Mineral Facts

Mineral	Location in Kerala	Significance
Monazite (Thorium)	Chavara (Kollam), Manavalakurichi (TN border), Coastal sands	India’s largest thorium reserves from monazite sand
Ilmenite (Titanium)	Chavara, Neendakara (Kollam)	IREL (Indian Rare Earths Ltd) mines here
Silica sand	Kozhikode, Alappuzha	Glass manufacturing
Clay (China clay)	Thiruvananthapuram, Kollam	Ceramics, pottery
Graphite	Palakkad, Kollam	Pencils, lubricants
Laterite	Widespread in Kerala	Building material (vettukallu — cut laterite blocks)
Bauxite	Limited deposits in Palakkad, Kollam	Aluminium industry

Soil and Mineral Conservation — Key Policies

Policy/Body	Role
Geological Survey of India (GSI)	Mineral exploration and mapping (est. 1851 in Kolkata)
Indian Bureau of Mines (IBM)	Regulation of mining and mineral conservation
MMDR Act, 1957	Mines and Minerals (Development and Regulation) Act — governs mining leases
National Mineral Policy 2019	Encourages private sector in exploration; promotes sustainable mining
Soil Health Card Scheme (2015)	Provides farmers with nutrient status and recommendations for soil

Quick Revision — PSC Frequently Asked

Question	Answer
Most widespread soil in India?	Alluvial soil
Regur soil is also called?	Black soil (or cotton soil)
Best soil for cotton?	Black soil
Why is black soil self-ploughing?	Swells when wet, develops cracks when dry
Laterite soil is found in Kerala because?	Heavy rainfall causes leaching; rich in iron/aluminium oxides
Oldest coalfield in India?	Raniganj (West Bengal)
Largest coalfield in India?	Jharia (Jharkhand)
Oldest oil field in India?	Digboi (Assam, 1889)
Largest offshore oil field?	Mumbai High (Bombay High)
India’s gold comes mainly from?	Karnataka (Kolar, Hutti)
Mica capital of India?	Koderma (Jharkhand)
Thorium source in Kerala?	Monazite sands (Chavara, Kollam)
Khadar vs Bhangar?	Khadar = new alluvium (fertile), Bhangar = old alluvium (kankar)
Neyveli is famous for?	Lignite mining (Tamil Nadu)