Prelims 2011 · archive
MediumSalinization occurs when the irrigation water accumulated in the soil evaporates, leaving behind salts and minerals. What are the effects of salinization on the irrigated land?
Answer & explanation
Answer: (b) It makes some soils impermeable
When salts build up in irrigated soil, especially sodium salts, the soil particles disperse and the soil loses its ability to pass air and water. Some soils therefore become impermeable. Higher water tables and water-filled pores come from waterlogging, which is a separate problem.
- ✗ (a) Salinization degrades land and cuts productivity. Salt in the soil makes it harder for crops to take up water, so yields fall.
- ✓ (b) Excess sodium disperses soil aggregates and lowers the soil's permeability to air and water. It also forms dense, impermeable surface crusts.
- ✗ (c) A rising water table is caused by over-irrigation and poor drainage, which is waterlogging. Waterlogging and salinisation are separate causes of land degradation.
- ✗ (d) Filling soil air spaces with water is waterlogging. Salinization is the accumulation of salts left behind when water evaporates.
Remember · Salinization leaves salts in the soil, degrades its structure and can make it impermeable. Waterlogging, which means a high water table and water-filled pores, is a different irrigation problem.
📘 Read it in NCERT: Class 12 India: People and Economy, Ch 9 (practise this chapter)
Sources
- FAO – Sodic soils and their management (Salt-affected soils) ↗ “the soil tends to become more dispersed which results in the breakdown of soil aggregates and lowers the permeability of the soil to air and water”
- NCERT Class 12 · India: People and Economy, Chapter 9 “Soil erosion, waterlogging, salinisation and alkalinisation of land lead to land degradation.”
Question: UPSC Civil Services (Preliminary) 2011, General Studies paper. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·