Soil profile

       Soil Profile 

    • The vertical section of soil is known as soil profile. 

    • The horizontal layer of soil profile is  known as Horizon.

      

O- Horizon

A-Horizon

A1 

A2

A3

B-Horizon

B1

B2

B3

C-Horizon

R-Horizon

      

O-Horizon

    • It is the first horizon only in forest area

    • It is also known as organic horizon

    • Most fertile soil is found in this layer

    • The coloration of this layer is dark

A-Horizon

    • It is the top most horizon in the land other than forest

    • It is also known as Mineral horizon

    • It is divided into A1, A2, A3.

    • Elluviation process occurs in the A2 region of A horizon, so this layer is also known as E- horizon

    • A3 is the intermediate between A and B horizon

B-Horizon

    • It is also known as sub surface horizon

    • It appears yellow in color

    • Illuviation process occur in this horizon

    • It is further divided into 3 regions, They are B1, B2, B3

C-Horizon

    • The parent materials are found in this layer

    • Rocks and soil are abundantly 

    • No organic matter are found

R-Horizon

    • Unweathered rocks and bedrock are wholly covered in this layer

    • Last horizon in soil profile

Some terms we have to clear about

Regolith: A+B+C      Root of plant:extends up to B1-B2

Solum: A+B

Top soil: 0-15 cm deep soil

Elluviation Process: Downward movement of nutrients and other minerals( washing out process)

Illuviation Process: Accumulation of minerals

Furrow slice: First 15cm deep soil collected and ovendried