Question

Sketch the cross section of soil and label the various layers.

Answer 1

A vertical section through different layers of the soil is called the soil profile. Each layer is different in texture, colour, depth and chemical composition. These layers are called horizons.

Cross section of soil looks as follows.
(i) A Horizon: It is called the topsoil. It forms the uppermost horizon. It is rich in humus and minerals and is dark in colour. This layer is soft, porous and can retain more water.

(ii) B Horizon: It is called the middle layer. It is harder and compact. It has a lesser amount of humus but more of minerals.

(iii) C Horizon: It is made up of small lumps of rocks with cracks and crevices.

(iv) Bedrock: It is the bottom-most layer. It is made up of hard rocks and hence this layer is very hard and difficult to dig further.