UPSC Previous Year Question | Prelims GS | 2018

With reference to agricultural soils, consider the following statements: 1. A high content of organic matter in soil drastically reduces its water holding capacity. 2. Soil does not play any role in the sulphur cycle. 3. Irrigation over a period of time can contribute to the salinization of some agricultural lands. Which of the statements given above is/are correct?

  1. 1 and 2 only
  2. 3 only
  3. 1 and 3 only
  4. 1, 2 and 3

Answer

Correct Answer

3 only

Explanation

Organic matter increases a soil's water-holding capacity, and soil is central to the sulphur cycle, so statements 1 and 2 are wrong. Long-term irrigation, especially with poor drainage, can cause salinisation.

Topics: geography, soil organic matter, soil properties and degradation, soils and agriculture, sulphur cycle and salinization