Describe the characteristics of arid soils. Why do the lower horizons of arid soil restrict infiltration of water?
Generated by claude-sonnet-4-6 · 2026-06-26 13:27 · grounding rag
Model Answer
Characteristics of Arid Soils:
- Colour ranges from red to brown.
- Texture is generally sandy and nature is saline.
- Salt content is very high in some areas; common salt is obtained by evaporating water.
- Lacks humus and moisture due to dry climate and high temperature.
- Evaporation is faster than moisture retention.
Why lower horizons restrict infiltration:
The lower horizons of arid soil are occupied by Kankar (calcium carbonate nodules) due to increasing calcium content downwards. This hard Kankar layer restricts the infiltration of water into the soil.
Source: Resources and Development, Chapter 1 — Arid Soils
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Explanation
- The question has two parts — characteristics (likely 2 marks) and reason for restricted infiltration (1 mark). Answer both clearly.
- The keyword examiner looks for is Kankar to explain restricted infiltration — never skip it.
- Mention sandy texture, saline nature, lack of humus/moisture, and red-to-brown colour for full credit on characteristics.