Quick Answer: ICAR Soil Classification of India

Soil Types of India: ICAR Classification and Crop Suitability Explained

Quick Answer: The ICAR classification of Indian soils recognises eight major soil groups: (1) Alluvial soils — rice, wheat; (2) Black (Regur) soils — cotton, sorghum; (3) Red soils — millets, groundnut; (4) Laterite soils — tea, coffee, cashew; (5) Arid soils — bajra, pulses with irrigation; (6) Saline-alkaline soils — reclaimed for wheat-rice; (7) Peaty-marshy soils — paddy in Kerala; (8) Forest-mountain soils — plantations and orchards. This grouping is the standard frame for UPSC and SSC Prelims questions.

Basis of Classification: ICAR vs USDA Orders

The Indian Council of Agricultural Research (ICAR) set up an All India Soil and Land Use Survey under which Indian soils were grouped into 8 major classes based on genesis, colour, composition, and location. The National Bureau of Soil Survey and Land Use Planning (NBSS&LUP), Nagpur — an ICAR institute — maintains the soil map of India and has classified soils into soil series and associations for land-use planning.

The USDA Soil Taxonomy, in contrast, is a global hierarchical system (orders, suborders, great groups) — India’s soils fall into orders such as Entisols (alluvial), Vertisols (black), Alfisols (red), Oxisols/Ultisols (lateritic), Aridisols (desert), Inceptisols and Mollisols (mountain). For Prelims, remember: ICAR uses 8 groups; USDA uses 12 global orders. Questions typically reference the ICAR list.

Alluvial Soils: Regions, Types (Khadar & Bhangar) and Crops

Alluvial soils cover roughly 40% of India’s land area — the largest share — spread over the Indo-Gangetic-Brahmaputra plains, coastal deltas and the Narmada-Tapi valleys. They are classified into:

• Khadar — new alluvium, freshly deposited by rivers in flood plains; fine, fertile, rich in humus and silt; ideal for intensive cultivation.
• Bhangar — old alluvium on higher terraces; coarser, often containing kankar (lime nodules); less fertile than khadar.

Chemically, alluvial soils are rich in potash but poor in nitrogen and organic matter (and sometimes phosphorus). They support the rice–wheat belt of Punjab, Haryana, Uttar Pradesh, Bihar and West Bengal, plus sugarcane, jute and pulses. Coarser alluvium in Punjab is locally called bhur; older deposits in the Gangetic valley are known as bangar with kankar.

Black Soil (Regur): Cotton Belt and Moisture-Rention Properties

Black soil, or Regur, derives from Deccan Trap basalt (lava soil) and covers the Deccan plateau — Maharashtra, Madhya Pradesh (Malwa), Gujarat, Karnataka and parts of Telangana. Key characteristics for Prelims:

• High clay content (montmorillonite) — exceptional moisture retention, ideal for rainfed cotton.
• Self-ploughing: develops deep cracks in summer that let air in and naturally turn the soil.
• Rich in iron, lime, magnesium and alumina; poor in nitrogen, phosphorus and humus.
• Forms deep cracks (wide cracking) on drying and becomes sticky when wet — farmers get more days of workability than sandy soils.

Best crops: cotton (hence “black cotton soil”), jowar (sorghum), bajra, wheat, oilseeds (groundnut, sunflower), and tobacco in Gujarat. In Vertisol taxonomy terms, these correspond to Vertisols.

Red Soils: Eastern and Southern Plateau Farming

Red soils develop over crystalline and metamorphic rocks (granite, gneiss) across the eastern and southern Deccan plateau, Odisha, Chhattisgarh, and parts of the northeastern hills. Their red colour comes from ferric oxide (iron) diffusion; the redder the soil, the higher the iron oxide content.

They are generally deficient in nitrogen, phosphorus, humus and lime, and need heavy fertilizer application and irrigation for good yields. Under intense leaching in high rainfall, red soils can undergo laterisation. Typical crops: groundnut, millets (ragi, bajra), pulses, potato, and with fertilizers, cotton and wheat in irrigated pockets (Alfisols).

Laterite Soils: Humid Zones and Plantation Crops

Laterite soils form in areas of high temperature and heavy rainfall with alternating wet and dry seasons — Western Ghats, Kerala and Karnataka coasts, Odisha, and hill areas of Assam and the northeast. Intense leaching removes silica and bases, leaving a soil rich in iron and aluminium oxides but poor in fertility, humus and nitrogen.

When cut and exposed, laterite hardens irreversibly into bricks — hence its use as a building material. With manuring, these soils support valuable plantation crops: tea, coffee, rubber, cashew and coconut. The laterite plateaus of the Western Ghats and Kerala are also serious erosion hotspots (see below).

Arid and Saline-Alkaline Soils: Desert Farming and Reclamation

Arid soils (USDA: Aridisols) cover western Rajasthan, Kutch, and rain-shadow zones of the Deccan. They are sandy, saline in patches, and poor in nitrogen and organic matter; soluble salts rise to the surface due to high evaporation. Kankar layers restrict water infiltration. Crops: bajra, jowar, ragi, pulses with irrigation (Indira Gandhi Canal belt).

Saline-alkaline soils (reh, kallar, usar) occur in the dry zones of Punjab, Haryana, UP and the Deccan — a consequence of over-irrigation and poor drainage. Reclamation uses gypsum (for sodic/alkaline soils), leaching, and salt-tolerant varieties.

Peaty-Marshy and Forest-Mountain Soils

Peaty-marshy soils form under waterlogged, high-rainfall conditions with heavy organic accumulation — notably the Kuttanad region of Kerala (below sea-level paddy), coastal Odisha, and Tamil Nadu marshes. They are black, heavy, acidic and rich in organic matter and salts; paddy is the main crop.

Forest-mountain soils occur in the Himalayan slopes and hill forests — thin, immature, and variable with altitude. In the higher ranges, they support orchards (apple in Himachal and Kashmir), while lower Himalayan and north-eastern hill soils suit tea, spices and plantation crops.

Soil Erosion Hotspots in India

Prelims increasingly pairs soil types with erosion geography. Know these hotspots:

• Ravines of the Chambal (MP-Rajasthan-UP) — deep gully erosion in alluvial tracts; the classic “badland” example.
• Shivalik chos (Punjab-Himachal foothills) — seasonal torrent gullies (“chos”) eroding foothill soils.
• Nilgiris and Western Ghats — steep-slope landslides and sheet erosion on laterite and forest soils.
• Laterite plateaus of Kerala-Karnataka — intense leaching and crusting.
• Wind erosion zone — arid Rajasthan, Kutch and the Indo-Gangetic dry belt, where sand dune movement degrades Aridisols.

Rule of thumb: water erosion dominates humid/plateau India; wind erosion dominates the arid west. As per ICAR/NBSS&LUP estimates, roughly half of India’s land faces degradation, with water erosion the largest single cause.

Government Conservation Schemes for Prelims

• Soil Health Card Scheme (2015) — provides every farmer a card with nutrient status of his/her soil and fertilizer recommendations; revised as SHC 2.0.
• Pradhan Mantri Krishi Sinchayee Yojana (PMKSY, 2015) — “Har Khet Ko Pani” plus its Soil Health Card and Per Drop More Crop components address moisture and nutrient management.
• National Mission for Sustainable Agriculture (NMSA) — promotes soil health management, organic farming (Paramparagat Krishi Vikas Yojana) and rainfed agriculture.
• Watershed Development Component of PMKSY (erstwhile IWMP) and the Desert Development Programme / DDP — check erosion in ravine, gully and desert areas.

For scheme notifications and budget details, verify at the official sources: PIB, Ministry of Agriculture, and ICAR.

Soil Map Practice: Match-the-Column and PYQs

UPSC Prelims repeatedly tests soil–crop–region matching and characteristics-vs-type questions. Practise this pattern:

Map pointers: trace the Chambal ravines (gully erosion), the Deccan Trap boundary (black soil), Western Ghats crest (laterite) and the Indo-Gangetic plain axis (alluvial) on an outline map — visual memory strongly improves Prelims accuracy.

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Frequently Asked Questions

Q: How many soil types are recognised by ICAR in India?

Eight major groups: alluvial, black, red, laterite, arid, saline-alkaline, peaty-marshy, and forest-mountain soils.

Q: Which soil covers the largest area of India?

Alluvial soil, covering roughly 40% of India’s land area, mainly in the Indo-Gangetic-Brahmaputra plains.

Q: Which crops grow best in laterite soil?

Tea, coffee, cashew and rubber in high-rainfall western coastal and northeastern hill regions.

Q: Why is black soil ideal for cotton?

High moisture retention and clay content; rich in iron, lime and magnesia but poor in nitrogen and phosphorus — moisture availability sustains cotton through long dry spells.

Q: What is the Soil Health Card Scheme?

A central scheme (launched 2015) that gives farmers a card reporting the nutrient status of their soil along with crop-wise fertilizer recommendations, updated through SHC 2.0 sampling cycles.

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