Question

Give reasons for the following.

Different regions in India have different types of soil.

Answer 1

1. Parent rock (source material): Soil inherits minerals from the underlying rock. Volcanic Deccan Traps give rise to black/regur soils, while weathering of ancient crystalline rocks produces red soils.
2. Climate (rainfall and temperature): Heavy tropical rain causes intense leaching and laterite formation in high‑rainfall zones (Western Ghats, Kerala); arid climate leads to sandy, saline desert soils in Rajasthan.
3. Relief/topography: Flat river plains accumulate transported alluvium (fertile Indo‑Gangetic plain); steep mountain slopes have shallow, stony soils that differ from lowland soils.
4. Agents of deposition and transport: Rivers deposit silt and form alluvial (riverine) soils; wind deposits form sand/dunes; glaciers and mass movement produce local mountain soils.
5. Vegetation and biological activity: Areas with dense vegetation add more humus, improving soil fertility; sparsely vegetated or heavily cropped areas have less organic matter.
6. Age and degree of weathering: Older, highly weathered soils (e.g., laterite, some red soils) differ in texture and fertility from younger, recently deposited alluvium.
7. Human influence: Irrigation, deforestation, cropping and soil management change soil properties locally (salinisation, erosion, addition/removal of nutrients).