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?

The correct option is 3 only.

Let us analyze each statement step-by-step to understand the scientific reasoning behind the answer:

Statement 1: Incorrect
Organic matter (humus) acts like a sponge in the soil. High content of organic matter enhances soil structure, improves porosity, and significantly increases its water holding capacity rather than reducing it. Therefore, Statement 1 is false.

Statement 2: Incorrect
Soil plays a vital and major role in the sulphur cycle. Sulphur is present in the soil in both organic forms (decomposing plant and animal residues) and inorganic forms (sulfates). Soil microorganisms break down organic compounds to release sulfates, which plants absorb through their roots. Thus, soil is an essential reservoir and medium for the sulphur cycle, making Statement 2 false.

Statement 3: Correct
Continuous irrigation, especially in arid or semi-arid regions with poor drainage, leads to waterlogging and water evaporation. As irrigation water evaporates, dissolved salts are left behind and drawn upward through capillary action to the soil surface. Over time, this leads to soil salinization. Hence, Statement 3 is true.

Since only Statement 3 is correct, the correct choice is 3 only.