An Introduction to Soil for the
Cleveland Market Gardener
What is Soil?
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Air
Water
Mineral particles
Organic Matter-Decomposed plant and
animal matter
• Live organisms-Bacteria, fungi, earthworms
(I like to refer to soil as a live body)
Soil composition
HEALTHY SOIL 50/50
Source: University of Hawaii
How are mineral particles created?
• Weathering
• Chemical & Physical
• Erosion
– Wind
– Water
• Heating, freezing and
thawing
Types of particles
• Clay “Smallest” <.002mm
• Silt
0.002-0.05 mm
• Sand “Largest” 0.5-1 mm
Soil Particles
Soil Profile
Soil Horizons
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O Horizon-The tops crust organic
matter
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A Horizon-Topsoil
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E Horizon-The transition are
between A &B horizon
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B Horizon-Subsoil
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C Horizon –Loosed unconsolidated
material
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R Horizon-Bed rock
Soil Texture
• The relative proportion of the 3 types of particles
• Influences water-holding capacity
• Ease of cultivation
What types of soil are these?
1. 20% sand, 20% silt and 60% clay
2. 40% sand, 40% silt and 20% clay
Soil Pyramid
Source: Dannyliford.com
Soil orders
Alfisols
• Occur under deciduous woodland or
grassland in humid areas of the world
• Generally productive agricultural
• Clay enriched B horizons
MIAMIAN -- OHIO STATE SOIL
The Miamian series consists of very deep,
well drained soils that formed in a thin
layer of loess and in the underlying loamy
till, which is high in content of lime. The
original vegetation consisted of
deciduous forest species, principally
white oak, maple, elm, ash, and hickory.
Miamian soils are the most extensive
soils in Ohio. They occur on more than
750,000 acres in the state. They are
productive soils. Corn, soybeans,
and winter wheat are the primary crops.
The average annual precipitation ranges
from 33 to 42 inches, and the average
annual air temperature ranges from 51 to
55 degrees F.
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Miamian Soil Profile
Surface layer: dark grayish brown silt loam
Subsoil - upper: dark yellowish brown clay loam
Subsoil - lower: yellowish brown clay and clay
loam
Substratum: yellowish brown loam
Soil Tilth
• Refers to the general
health of the soil
• “Ease of tilling”
Soil pH
“potential hydrogen”
• Concentration of H+
compared to distilled
water
• Logarithmic scale
Global Soil pH
Global variation in soil pH. Red = acidic soil. Yellow = neutral soil. Blue =
alkaline soil. Black = no data.
Soil Structure
• The way soil in bound
together in clumps
known as aggregates
• Formed by the
production of a by
product of fungi called
“glomulin”
• Ideal soils have mix of
small, medium and
large
Soil structure
AIR AND WATER MOVEMENT
DEPENDENT ON
PORE SPACE
• Macro pores
• Micro pores
DRAINAGE
• Rate of water movement
through and across soils
• Water should occupy
50% of pore space
Internal Drainage
• Affected by:
– Texture
– Structure
– Physical condition
The organic fraction of the Soil
Most dynamic fraction
of the soil
Humus
• Stable organic matter
• Will not break down
any further
• Sometimes refer to as
mature compost
• Advantages
• Buffer against acidic
or basic soils
• Warms up soil
• Increase water
holding capacity
Micro fauna
• Bacteria
• Fungi
• Protazoa
IMPORTANCE
CANNOT BE OVER
STATED!!!
Macro fauna
• Earthworms
• Nematodes
• Insects
• Mollusks
Where do you find macro fauna?
Cation Exchange Capacity
• The total number of
negative sites on a
clay soil or humus
• The soils ability to
absorb (exchange)
certain nutrients
• The higher the better
Soil Amendments
• Something we add to the soil to improve it’s quality and or structure
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Fertilizer
Peat moss
Compost
Manure
Worms
Inoculants
Sharp sand
Lime
Cover Crops
Mulches
Sewage sludge
Compost
• A mix of decayed plant
and animal matter used
to improve soil
• Everyone should do
it!!!!
• In most cases should
be used as an
amendment
Cover crops and green manures
MANY ADVANTAGES
• Some are nitrogen
fixing
• Add “tilth”
• Scavenge nutrients
Mulches
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Leaves
Grass clippings
Wood chips
Cardboard
Newspaper
Inoculants
• Bacterial
• Fungal
Peat
• Decayed plant matter
• Improve structure
• Improve water holding
capacity
• Improve lower pH
Soil Preparation for home
gardeners
• Tilling
• Double digging
• Broad forking
Damaged Soil
Photo credit: Joe Boggs
How do we damage our soil
• Compaction
• Working when wet
• Walking or moving
large equipment
• Over usage of tillage
equipment
• Over fertilization
How does compaction damage
soil?
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Destroys aggregates
Destroys macro pore space
Total pore space destructions
Affects internal drainage
How does tilling affect the soil?
• Pulverizes soil
• Earthworms leave
• Organic matter is loss
PARTING THOUGHT
“The nation that destroys
its soil destroys itself”
Franklin D. Roosevelt