Climate as a soil-forming factor
Topic: Geomorphic Processes: Weathering, Mass Movement, Erosion and Soil Formation · NCERT: Class 11, Ch 5 "Geomorphic Processes"
Meaning
Climate is one of the five soil-forming factors. It is an active factor, along with biological activity. It works through moisture (rainfall, evaporation, humidity) and temperature.
- Where there is excess water, material is washed down (eluviation) and laid down in lower layers (illuviation).
- In wet equatorial areas, heavy rain removes calcium, sodium, magnesium, potassium and most of the silica. Removing silica is called desilication.
- In dry areas, water rises to the surface and evaporates, leaving salt crusts called hardpans.
- Where rainfall is intermediate, kanker (calcium carbonate nodules) forms.
Temperature controls how fast chemical and biological activity happen. Humus builds up in cold climates, where bacteria work slowly, and stays low in humid tropics, where it breaks down fast.
Example
Heavy rain on the Western Ghats in Kerala produces leached, red laterite soils. In dry western Rajasthan, evaporation leaves salt crusts on the soil surface.
Don't confuse with
- Parent material: a passive factor, the rock or sediment the soil forms from. Climate actively changes that material.
Related concepts
- Soil-forming factors
- Parent material
- Residual and transported soils
- Eluviation
- Illuviation
- Desilication
- Humus
- Peat