The earth is not all the same and its appearance depends on many factors : the animals and plants that live in that soil and enrich it when they decompose and become waste ; types of rocks and climate ( temperature, precipitation and wind ) .

The SOIL , the most superficial part of the ground can have different colors depending on what it contains.

When the ground is reddish contains much iron ; the humus is located in the forest is very dark and very suitable for cultivation. A white and pink sand indicates the presence of coral and shell fragments .

The teacher showed us three types of land : SANDY GROUND , CLAY SOIL and COMMON . The first was light yellow in color , with uniform and fine grains ; the second looked like plasticine and handled with his hands , it was very dark and torn into pieces not joined together . The common soil is suitable for most of the crops .

It also contains small stones , straw, grass clippings .