Transcript Soil Science

Soil Science
Written By Jim Melby
Revised By Sam Behrends
Winneconne High School
Horticulture
The Basics
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Media-a substance in
which you can grow
plants
Can be soil or a soil
substitute
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Hold moisture
Supports the plant
Provides nutrients
The Basics
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1.
2.
3.
4.
5.
6.
Soil: Earthen-based
media
Sand
Silt
Clay
Organic matter
Living organisms
Pore spaces (water
and ‘air’)
The Basics
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Soil is
classified
according to
the % of sand,
silt, and clay it
contains
WI State SoilAntigo Silt
Loam
The Basics
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Particle Size:
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Sand is the largest
Silt is in the middle
Clay is the smallest
Pictures
Soil Composition
Soils ‘vary’ greatly in general composition
due to two main factors
1. Rocks breaking down over thousands of
years
2. Materials that have been relocated by
water
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Soil Profile
Organic Matter
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Organic Matter is the top layer of most soil
profiles
Not always present
Typically living materials such as sod,
weeds, or even moss
Top Soil
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Contains some organic matter
Typically the depth to which you would
plow or till
Typically the ‘highest quality’ for growing
Subsoil
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Reached by the deep rooting plants
Roots will penetrate deep into subsoil due
to the fact that some oxygen does exist
A mixture of bedrock and top soil
Bedrock
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Mostly solid material
Hard clay and rocks
Little to no root penetration
Ideal Soil
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50 percent solid material
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Will be full of valuable minerals
Some OM will be present
50 percent pore space
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Small holes fill with oxygen and water
Eight Physical Properties of Soil
1-Texture
How it feels….sandy, silty, or clayey
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2-Structure
Granular, Platy, blocky, prismatic, columar
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Eight Physical Properties of Soil
3-Soil Density
Measurement of the physical ‘looseness’ or
‘compaction’ of soil
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4-Soil Consistency
How well soil sticks together or resists
fragmentation
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Eight Physical Properties of Soil
5-Pore Space
Open volume for air and water
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6-Soil Color
Can be an estimate of moisture, organic
matter (OM), salt, boundaries
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Eight Physical Properties of Soil
7-Soil Temperature
Regulates germination and root growth
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8-Water Content
Possibly the most important factor as it
relates to all other properties of soil
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Properties Influence…
1.
2.
3.
4.
5.
Water Intake
Water Storage
Ease of Tilling or Plowing
Amount of Aeration
Amount of Fertilization
Chemical Properties
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Chemical properties of soil are what the
soil is made up of.
Certain chemical properties make soils
better or worse for growing certain plants.