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WHAT IS SOIL?

 

Most of the land in the world is covered with soil.

But what does soil do?  
   
Soil is extremely useful.  
   
Soil enables plants to grow.

 
   

 

Soil supports the plant in the ground.

 
   
Soil supplies the plant with nutrients and water. These are taken in by the roots.

 
   

Soil is home to millions of insects, termites and worms.

 

 

 
 
   


Soil takes many many years to form and is made up of a mixture of different things.

The four main components of soil are:

1) Pieces of finely ground rock.

2) Humus (humus is made up of little bits of decayed leaves and tiny pieces of rotting wood, seeds and decayed plants and animals). This is rich in nutrients.

3) Water

4) Air


There are different layers of soil.

THE TOP LAYER is the richest in NUTRIENTS as it contains the most HUMUS. This soil is usually dark in colour.
 
 
SECOND LAYER is called SUB SOIL and contains very little HUMUS.


HOW IS SOIL FORMED?

 

Both top soil and subsoil are made up of rock ground down over many years by:

rain, running water, frost, heat and wind.

This process is called EROSION.

Soil is different in different parts of the country and the world.

This is because the rocks and organic matter that make up the soil are different in different parts of the country and the world.


The different types of rock that are ground down, make different types of soil.

 SANDY SOIL   Is light and dry and because it contains large amounts of air water drains through easily.
     
 CLAY SOIL   Is very heavy and quite sticky when wet. Because it is so sticky and heavy, water does not drain though easily.
     
GRAVELLY SOIL   Is full of tiny stones and because of this water drains away quickly
     


Who lives in the soil