Page 27 - full

Soil Profile

Soil is made up of distinct layers,
called profile or horizons. Each layer
has its own characteristics that make
it different from all of the other
layers.
O HORIZON- This is the top layer of
soil that is made up of living and
decomposed materials like leaves,
plants, and bugs. This layer is very
thin and is usually pretty dark.
A HORIZON- This is the layer that we
call "topsoil" and it is located just
below the O Horizon. This layer is
made up of minerals and
decomposed organic matter and it is
also very dark in color. This is the
layer that many plants roots grow in.
B HORIZON- This is the layer that we
call "subsoil" and it is located just
below the A Horizon. This layer has
clay and mineral deposits and less organic materials than the layers above it. This layer
is also lighter in color than the layers above it.
C HORIZON- This is the layer that we call "regolith" and it is located just below the B
Horizon. This layer is made up of slightly unbroken rock and only a little bit of organic
material is found here. Plant roots are not found in this layer. wn as the subsoil layer.

Soil Erosion

The soil erosion is a natural process. The topmost layer of soil is very fertile and best
for the growth of plants. Sometime, this topsoil is removed by strong wind and water.
The removal of the fertile soil by the action of wind and water is called erosion of soil.
Strong wind, heavy rain, cutting down of trees and overgrazing etc. are the main
causes of soil erosion.

31