Soil Profile

Soil is one of the most important natural resources.

It is the home to many plants and organisms.

The soil appears like one layer.

But it is found to have several layers when we look into a pit or a roadside cut.

These layers are called soil horizons.

The arrangement of horizons in the soil is known as the soil profile.

The four prominent horizons of the soil are A, B, C and bedrock. Each layer differs in colour, texture, structure and thickness.

The uppermost layer is called the topsoil or the A horizon.

Topsoil is soft, porous, dark in colour and rich in humus.

The humus makes the soil fertile and provides nutrients to growing plants.

It is also home to many living organisms such as worms, rodents, moles and beetles.

The second layer is called the B-Horizon.

This layer is compact and hard.

It contains less of humus but more of other minerals.

The third layer is the C-horizon also called the parent rock.

It consists of lumps of rocks with cracks and crevices.

C- layer comprises the parent rock.

It is called the parent rock because the texture, colour, and all other properties of soil depend on it.

The bottommost layer is called the bedrock.

It consists of unweathered solid rock which is difficult to dig with a spade.

Revision

Soil is one of the most important natural resources.

It is the home to many plants and organisms.

Soil is not just one layer, but it is found to have several layers.

The four prominent horizons of the soil are A, B, C and bedrock. Each layer differs in colour, texture, structure and thickness.

The End