Download What is Soil? Student Notes what_is_soil1

Name
_______________________________
Soil is a __________ at the surface of the earth composed of a mixture of
____________, ___________, _____________, _______, _______ which is
capable of supporting the growth of plants
Factors of Soil Formation
o Parent material (original type of rock)
 Residual soil: formed from _______ bedrock
 Transported soil: _______ material has been moved to a new location
o Climate: ________________
o Vegetation, Slope, Time, and ___________ of all factors
Soil Composition (by volume of a healthy soil)
 Weathered rock and mineral matter (dirt)(~45%): ______ and ________
most abundant minerals. Must contain _________, ________, and ______
 Organic matter (humus) (~5%): Partially decayed _______ and
___________________with soil. Supplies food for ________________.
 Air (nitrogen, oxygen, carbon dioxide) (~25%): Used by soil organisms and
plants
 Water (~25%): A solution of water and dissolved ________ and ________
 Pore spaces: allows for penetration of __________ and circulation of ___
and _________
 Soil organisms: Some __________ organic matter
releasing ________ back into the soil and some
change atmosphere _________ into nitrogen
_____________ (nitrates)
Soil Profile: as soil develops, it forms separate soil layers called ____________
o “O” horizon (not a true layer):
Fresh or partly
decomposed ____________ (humus) sitting on _____
of the soil (litter) and highest concentration of
_______________
o “A” horizon:
_______, most weathered layer, most
_______ layer, high humus content (nutrients), many
microorganisms, _______ color due to humus, Zone of
leaching (water ____________ minerals and carries
them down to a lower layer), the most
roots present,
and the parent material unidentifiable
o
o
o
“B” horizon: Subsoil (fill dirt), less root penetration,
less biological activity, compact and ________ in color,
Zone of accumulation (where leached materials are
________), many more rocks, and parent material
difficult to _____________
“C” horizon: Little biological activity, ____________
weathered parent material, and more and larger rocks
“R” horizon (not a true layer of soil): ___________ and _____________ parent material
Soil Erosion is the _______________ of soil
Agents
Water
• Raindrops hit the soil and dislodge soil particles
• Thin sheets of water (sheet flow) flowing across
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the surface carries away dislodged soil particles
(sheet erosion)
Sheet flows collect in tiny channels called rills
Rills drain into gullies
Gullies drain into streams
Streams drain into rivers
Rivers flow to the oceans where the soil is
deposited
Wind, Ice (glaciers), and Human activities
Special Soils
Soil by Brainpop
1) What is Humus?
2) What is the “Horizon A”
layer of soil also known as?
3) What is “bedrock”?
o Laterites (Brick Soil): ______________soils form in the _________ and
o
___________ and is the end product of __________ chemical weathering
Tundra: Soils near the ____________, _____________ with little humus, and
supports only small plants, no trees