Question

what is soil profile ? discuss the various horizons in the soil profile ?

Answer 1

Soil profile

The soil found in layers, which are arranged during the formation of soil. these layers are called horizons the sequence of soil. the layers of soil can easily observe by the colours and size of the particles. the main layer of soil are topsoil, subsoil and parent rock. each layer has its own characteristics.

the features of layers of soil plays an important role in determining the use of soil. The soil that has developed three layers, is mature soil. It takes many years under favourable condition for the the soil to develop its three layers. At some places, the soil contains, only two layers. Such soil is immature soil.

Horizons of soil

Soil consist of following horizons

• Horizons A or topsoil

It is also called as humus layer, which is rich organic material. these layer consist of decompose materials and organic materials. This is the reason, topsoil has drak Brown colour. the humus make the topsoil soft porous to hold enough air and water. in this layer, seeds germinated and roots of a plant grow. many organisms like earthworm, millipedes and centipede, bacteria and fungi are found in this layer of soil.

Horizons B or subsoil

• just below the topsoil there is another layers called horizons B or subsoil. It is comparatively hard and compact than the topsoil. It is light in colour than top soil because it is less humus in this layer. This layer is less organic but rich in minerals brought down from the topsoil. it contains metal salt especially iron oxide in a large proportion. Farmers upon mixed with horizons A and horizons B.when ploughing their fields.

Bedrock and horizons C

• Bedrock is also known as parent rock and lies just below the subsoil. contains no organic matter and made of rocks and stones, it is so hard . this layer represent transition zone between the Earth's Bedrock and horizons A and B.

Answer 2

Answer:

A vertical section through different layers of soil is called soil profile

Explanation:

horizon A or topsoil

this layer is generally soft ,porous and can retain more water

horizon B or middle layer

this layer has lesser amount of humus but more minerals. This layer generally harder and more compact

horizon C

it is made up of small lumps of rocks with cracks and crevices

bedrock

it is very hard and difficult to dig with a spade