Indian Soils
Notes
The ICAR groups Indian soils into eight major types. Soil is formed by parent rock, climate, relief, vegetation and time.
Soil | Parent material and features | Regions | Crops |
|---|---|---|---|
Alluvial | Deposited by rivers (Khadar and Bhangar); the most widespread (about 40% of the area) and the most fertile; rich in potash and lime, poor in nitrogen and humus | Northern plains, east coast deltas | Rice, wheat, sugarcane, jute |
Black (regur) | Weathered Deccan Trap basalt; clayey, moisture-retentive; self-ploughing (swells when wet, cracks when dry); rich in calcium, magnesium, potash, iron; poor in nitrogen, phosphorus and organic matter | Maharashtra, Gujarat, Madhya Pradesh, Karnataka, Andhra Pradesh, Telangana | Cotton (the "black cotton soil"), soybean, sugarcane |
Red | Crystalline igneous and metamorphic rocks; colour from iron oxide; porous; low in nitrogen, phosphorus and humus | Tamil Nadu, Karnataka, Andhra Pradesh, Odisha, Chhattisgarh, Jharkhand | Millets, groundnut, pulses |
Laterite | Heavy rain with alternating wet and dry seasons causes leaching; acidic, low fertility; rich in iron and aluminium | Western and Eastern Ghats, Kerala, Karnataka, Odisha, Assam, Meghalaya | Tea, coffee, cashew, rubber; bricks |
Arid (desert) | Sandy, saline, low humus; calcareous layer (kankar) | Rajasthan, Gujarat, Haryana | Bajra, jowar; crops with irrigation (Indira Gandhi Canal) |
Saline and alkaline | Called usar, reh, kallar; salt accumulation by poor drainage and irrigation | Punjab, Haryana, Uttar Pradesh, Rajasthan, Gujarat coast | Salt-tolerant crops after reclamation (gypsum) |
Peaty and marshy | Rich in organic matter, acidic | Kerala (Kari soil), Sundarbans, Odisha, Tamil Nadu | Rice |
Forest and mountain | Vary with altitude; acidic at higher levels | Himalayan slopes, Western and Eastern Ghats | Tea, coffee, fruits, spices |
Soil erosion: sheet erosion, gully erosion (the Chambal ravines), wind erosion; caused by deforestation, overgrazing, shifting cultivation and heavy rain.
Soil conservation: contour ploughing, terrace farming, strip cropping, shelterbelts and afforestation, check dams, gully plugging, crop rotation and zero tillage. The Soil Health Card Scheme (2015) advises farmers on nutrients. World Soil Day is observed on 5 December.
Key Points
- ICAR: eight soil groups; alluvial is the largest and most fertile.
- Black soil (regur): from Deccan Trap; ideal for cotton; self-ploughing.
- Red soil: iron oxide; laterite: leaching, acidic; used for plantation crops.
- Saline soils: usar, reh, kallar; peaty soil: Kerala's Kari.
- Conservation: contour ploughing, terracing, shelterbelts.
MCQs
Q1. Black soil is best suited for:
(a) Rice
(b) Cotton
(c) Tea
(d) Wheat only Ans:
(b).
Q2. The soil formed by leaching under heavy rainfall and alternating wet and dry conditions is:
(a) Alluvial
(b) Laterite
(c) Black
(d) Arid Ans:
(b).
Q3. The most widespread soil in India is:
(a) Black soil
(b) Red soil
(c) Alluvial soil
(d) Laterite soil Ans:
(c).