In the soil-forming regime, which one of the following occurs in a region where evapotranspiration exceeds precipitation significantly?

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.

Why the others are wrong

• (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.

Key facts

• 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.

Common traps

• Choosing laterization/podsolization, which need a water surplus (leaching).
• Confusing calcification (dry) with gleization (waterlogged).

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).