Question

Match the following and choose the correct option:

$\begin{array}{cc}i.\text{A - horizon}& a.\text{Small lumps of rocks}\\ ii.\text{B - horizon}& b.\text{Partially decomposed organic matter}\\ iii.\text{C - horizon}& c.\text{Rich in humus, living creatures, and inorganic minerals}\\ iv.\text{O-horizon}& d.\text{Less humus and more minerals, compact}\end{array}$

• A. i - a; ii - b; iii - c; iv - d
• B. i - b; ii - c; iii - a; iv - d
• C. i - c; ii - d; iii - a; iv - b
• D. i - d; ii - c; iii - b; iv - a

Answer 1

The correct option is C

i - c; ii - d; iii - a; iv - b

Horizon O is a layer of partially decomposed organic matter lying above topsoil.

Horizon A is the topsoil. It is dark in colour due to the presence of large amount of humus. It makes the soil nutrient rich and fertile. The layer is soft, porous and can retain more water.

Horizon B is the layer below horizon A and has less quantity of humus but at the same time it contains more minerals.

Horizon C is the layer which is composed of partially eroded small lumps of rocks.