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Soil is the _______ and _______ ______ that supports plant growth on the earth's surface.
mineral, organic matter
Soil is a mixture of particles of ____, _______ _________, ______ _________, ___ and _____.
rock,organic materials, living organisms, air, water
Why is soil important?
plant growth, habitat for microbes, renew water(acts as a filter),sites for structures, reservoirs (ponds, lakes), waste disposal
Who depends on soil?
everyone
Four major components of soil
mineral, water, air, organic matter
Sand particle size
largest
Sand dry time
quick
How much water does sand hold?
not much
Is sand fertile?
no (low fertility)
Silt particle size
medium
Silt fill space between ____.
sand
Silt is often moved by _____.
water
Silt fertility
fertile
Clay particle size
smallest
Clay fills space between
Sand & silt
How much water does clay hold?
a lot
Clay dry time
slow dry time
Does clay hold nutrients
yes
What soil texture is most soil?
Sand, silt, & clay
What are the three soil textures?
sand, silt, & clay
What is written on the 3 sides of the soil triangle going from the bottom to the right?
sand, silt, clay
The soil triangle shows the __________ of the soil texture in soil.
proportion
Soils are like
fingerprints
no 2 soils are
alike
each soil has its own unique set of
characteristics
If you cut soil out of the ground you will see many of these
characteristics
What is the chunk of soil cut out of the ground called
soil profile
A soil profile the face of the soil when you cut it __________.
vertically
Where can you find soil profiles?
ditch, hillside, etc.
What can a soil profile indicate?
properties today and climate history
What can you see clearly on a soil profile
layers
What are soil layers called?
horizons
A soil horizon is an identifiable soil layer that differs in ________ __________ and ________ ___________ from the _____ next to it.
physical properties, chemical composition, layer(horizon)
Soil horizon differ in
color, particle shape, texture
soil horizons can easily be seen where _____ have been cut into _________ or where _______ have cut through _______
roads, mountains, streams,valleys
Soil horizon alphabetical code
O A B C R
Is every horizon found in every soil?
No
Where is the O layer located
top layer
The O layer is made up of
organic materials
Organic materials
decaying leaves, twigs, moss, insects & animals
Where is there no O horizon and why
Deserts and agriculture fields (because of plowing)
The A soil is the
topsoil
The A horizon is made mostly of
minerals
The A horizons is what color
dark rusty color
The A horizon is the layer that is
tilled
The B horizon is the _______.
subsoil
The B horizon may be high in
clays and metals
The B horizon is what color
a light color
The B horizon is usually lower in _______ ______ than O or A
organic matter
The C horizon consists of _____________ ______ ________
disintegrated parent material
Because this layer is deeper it has less
organic material
The R horizon is the ______ layer.
lowest
The R horizon is made of
bedrock
Bedrock is ____ to dig in
hard
Note 
Flashcard (60)