In the soil-forming regime, which one of the following occurs in a region where evapotranspiration exceeds precipitation significantly?
- (a)Calcification
- (b)Laterization
- (c)Podsolization
- (d)Gleization
Correct — A, Calcification. Where evapotranspiration significantly exceeds precipitation (semi-arid/dry climates), water moves upward and calcium carbonate is deposited in the soil profile, forming lime-rich (kankar/caliche) horizons. This soil-forming process is calcification.
- (b)Laterization — Laterization occurs in hot, WET tropical climates where heavy rain leaches away silica and bases, leaving iron and aluminium oxides — the opposite moisture regime.
- (c)Podsolization — Podsolization occurs in cool, humid (often coniferous) regions where acidic leaching removes iron and aluminium from the upper soil — again a wet, leaching environment.
- (d)Gleization — Gleization occurs in waterlogged, poorly drained soils where reducing conditions produce grey, mottled 'gley' horizons — a saturated, not dry, setting.
Soil-forming (pedogenic) regimes depend on the balance of moisture and temperature. When rainfall exceeds evaporation, water percolates DOWN and leaches soluble material (laterization in the wet tropics, podsolization in cool humid areas). When evapotranspiration exceeds precipitation, capillary water rises and deposits salts and carbonates near the surface — calcification. Waterlogging gives gleization.
The key phrase is 'evapotranspiration exceeds precipitation' — a moisture DEFICIT with upward water movement, which accumulates calcium carbonate: calcification. The other processes belong to wet or waterlogged regimes.
- Calcification: calcium carbonate accumulates where evaporation exceeds rainfall (dry regions).
- Laterization: leaching of silica/bases in hot wet tropics -> iron/aluminium oxides.
- Podsolization: acidic leaching in cool humid (coniferous) regions.
- Gleization: reducing, grey 'gley' soils in waterlogged conditions.
- Choosing laterization/podsolization, which need a water surplus (leaching).
- Confusing calcification (dry) with gleization (waterlogged).
Asked as which soil process matches a given moisture regime, esp. dry (evaporation-dominated) areas.
No directly related past PYQ was found.
- practice — not a real PYQ
Laterization is typical of which climate?
- (a)cold desert
- (b)hot and humid tropics
- (c)semi-arid
- (d)waterlogged
Answer(b) hot and humid tropics.
- practice — not a real PYQ
Grey, mottled 'gley' soils form under which condition?
- (a)strong evaporation
- (b)waterlogging (poor drainage)
- (c)acidic leaching
- (d)lime accumulation
Answer(b) waterlogging (poor drainage).