Soil - Cloudfront.net
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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.