Question

A fertile agricultural soil appears deep coloured at the surface as compared to the soil one metre down. The reason for the colour of topsoil is due to

• A. Organic matter
• B. Fertilizers
• C. More moisture
• D. Recent formation

Answer 1

The correct option is A

Organic matter

Topsoil contains leaves and organic constituents which decompose to form the upper organic layer, known as humus. The humus content in soils plays a very important role in its fertility and thus makes the topsoil fertile. The reason for the colour of topsoil is due to the organic matter present in it.