BACKGROUND:
Soil is composed of organic matter
and broken down rocks. The organic matter is from other surrounding
life that has started to mix with the small rocks. Many soil dwelling
organisms spend their lives breaking down dead animals and plants, releasing
nutrients for use by growing plants. These decomposers, sometimes
called reducers, are responsible for the fertility of the soil.
Erosion caused by water, wind, and heat can
break the rocks down. Even living things such as lichens and plant
roots contribute to the breaking down of rocks. Rocks are made of
minerals, and minerals have many helpful elements in them that can be chemically
released. This process, together with the decomposition of
organic matter, eventually leads to the creation of new soil. However,
this can take a very long time, one inch of topsoil may take five hundred
years to form. .
PROCEDURE:
- The worksheet tries to put all the
information together, so students can see how it is all related.
See if the students can figure out what is going on and have them state
what they think is going on in the picture.
- (1) Dead leaves and other plant and
animal matter.
(2) Decomposers break down organic matter.
(3) Rocks broken
down.
(4) Minerals and other nutrients released into soil.
(5) Plant
grows.
(6) Water and air penetrate soil.
