Showing posts with label Humus. Show all posts
Showing posts with label Humus. Show all posts

Sep 6, 2016

What are the Layers of Soil?



Soil is a living, breathing, natural entity composed of soilds, liquids and gases.  It has five major functions:

Ø  Provides a habitat for organisms
Ø  Filters water
Ø  Provides a medium for plant growth
Ø  Recycles waste products
Ø  Serves as an engineering material

An Ideal soil for plant growth contains 50% pore space and 50% solids with the pore space filled with equal parts of air and water.

Given below  is a vertical section of the soil that depicts all its horizons which extends from soil surface to parent material:

S.No
Horizon
Layer Composition
1
O(humus/organic)
Surface horizon contain various organic matter mainly decomposing leaves and differs from place to place
2
A ( Top Soil )
Surface horizon contains minerals such as sand, silt and clay and organic matter.  Found mostly in the surface layer of Agricultural lands and grasslands.
3
E(eluviated horizon)
Sub-surface horizon where the soils are leached. Missing in some soil but mostly found in older and forest soils.
4
B(sub– soil)
Sub-surface horizon that holds the minerals leached from the above horizons.
5
C(parent material)
Sub-surface horizon, the deposits at earth’s surface from which the soil is developed
6
R (bedrock)
Mass of rocks such as granite, lime stone or sand stone that forms the parent material for some soils.


 See also :