Transcript Soil - Cloudfront.net

Soil
Essential Question
What
is Soil?
Observing Soil - What do you
see?
Soil Composition
Soil
is a mixture of four materials
Weathered
rock particles
Organic matter
Water
air
Humus
The
decayed organic matter in soil.
Organic matter comes from the
remains and waste products of plants,
animals and other living things.
Factors that form soil
The
kind of rock in the area
The area’s climate
The landforms in the area
The plant cover in the area
The animals and organisms in the
area
Time
Soil Horizon
A
layer of soil with
properties different from
the layers above and below
it.
Soil Horizon
Horizon
A - The upper layer or topsoil.
Contains the most organic matter (humus)
and is dark in color.
Horizon B - The layer under A that
contains clay and minerals and is usually
brownish or reddish in color.
Horizon C - The deepest layer of soil.
Contains the largest and least weathered
rocks. It is usually yellowish brown.
Soil Horizon
How do organisms effect soil?
Plants
- provide organic matter or humus
to the soil.
Microorganisms - decomposers like
bacteria and fungi that decompose dead
plants and animals and return nitrogen to
the soil.
Animals - loosens and mixes the soil as
they build their homes which adds air to
the soil. They also add humus when they
die.
What are the properties of soil
Texture
Color
Pore Space
 Chemistry
All of these observations and test
tell what nutrients the soil contains
and what plants will grow best.
