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The Origin of Soil and Its Properties
Andrew Hammermeister
Organic Agriculture Centre of Canada
Dalhous...
How can I live my life stepping on this
stuff and not wonder at all?
William Bryant
“Probably more harm has been done to soil
science by the almost universal attempts to look
upon the soil merely as a produ...
A Rainbow of Soil
A rainbow of soil is under our feet;
Red as a barn and black as a peat.
It’s yellow as lemon and white a...
Soil is any naturally-occurring, unconsolidated
(loose) material on the surface of the earth,
which will support plant gro...
Soil
• Basic resource sustaining all terrestrial
ecosystems.
• Soils are not a renewable resource in the scale of
human li...
Soil performs 3 main functions:
1. Provide a medium for plant growth
2. Regulate and partition water flow through the
envi...
Soil is a product of:
Parent material
Climate
Topography
Biology
Time

Humans!
Influence of Parent (geological) Material
Glacial deposition
(Photo K.Murray)

Glacial Action
(Photo J.C.Miller)

Soil for...
Fluvial materials – sorted by water
Aeolian materials – sorted by wind
Influence of Parent (geological) Material
Bedrock
(Photo A.R.Aandahl)

Fluvial sediment
(river deposits)
(Photo A.R.Aandah...
Influence of Parent (geological) Material
Tidal deposits
(Photo J.C.Miller)

Tidal landscape (Stewiacke River)
(Photo J.C....
Influence of Climate (precipitation)
“Essentially, all life depends upon the soil ...
There can be no life without soil and no soil
without life; they have evo...
Soil Ecology

The soil biological community can weigh from 1100 to 14000
kg/ha; a similar weight as 2 to 28 yearling steer...
Soil biology
(soils.usda.gov/sqi/concepts/soil_biology/arthropods.html)
Earthworm burrows
Topographic (land shape) effects
Slope effects on soil
serc.carleton.edu/details/images/12506.html
Ecosystems and biology
Ecosystem and biology

Eastern Acid Forest Soil &
Landscape (Podzol)

Prairie Black Soil
(Chernozem)

(Photos - Agricultur...
“The nation that destroys its soil, destroys itself.” --Franklin Delano Roosevelt
“Plowed ground smells of earthworms and ...
Soil colour is related to organic matter
content, iron oxides, and drainage.
Munsell soil color charts
•

www.organicagriculture.co/
Soil organic matter
Component

Rate of
decay

• Serves as food for soil
organisms
• Stores and provides plant
nutrients
De...
Organic matter builds structure
Sticky byproducts of decay

Soil aggregation - organic "glue" binds
mineral particles toge...
Soil organisms shape the soil
Soil aggregation - burrowing
organisms (S.S.S.A.)

Worm castes (S.S.S.A.)
The stability of soil structure
Soil Minerals

Clay Mineral

Clay Mineral (Koalinite)

Clay minerals - shrinkage & swelling
Soil Particle Size Classes
Most Important Aspect of Soil Texture = SPECIFIC SURFACE.
(Specific Surface = Total area on par...
Influence of soil separates on other
soil properties (T.J. Rice, 2002)
Property
Water holding
Aeration when moist
Soil org...
Soil Structure (aggregation)
Factors influencing soil structure
Soil aggregation wetting/drying & clay content

Soil aggregation - Tillage
Andy’s favorite:
Solodized
Solonetic
Soil
(Found in the
prairies)
Cation Exchange Capacity (CEC)
CEC: The capacity of the soil to hold cations
(positively charged molecules)

Black – collo...
Cation Exchange Capacity (CEC)

Black – colloid of clays & humus with a negative charge, attract cations (+ ions).
Dark bl...
Soil pH

• pH: measure of the concentration of H+ in soil
solution:
pH = - log [H+]

• Therefore, low pH value, means high...
“... only rarely have we
stood back and
celebrated our soils as
something beautiful,
and perhaps even
mysterious. For what...
dal.ca
www.dal.ca

Visit

OACC.INFO for

Production, research and market information
Upcoming workshops & symposiums
Virtu...
Visit

•
•
•
•
•
•

OACC.INFO for

Production, research and market information
Upcoming workshops & symposiums
Virtual far...
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
Hammemermeister origin of soil & its properties.acorn
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Hammemermeister origin of soil & its properties.acorn

  1. 1. dal.ca www.dal.ca The Origin of Soil and Its Properties Andrew Hammermeister Organic Agriculture Centre of Canada Dalhousie University, Faculty of Agriculture
  2. 2. How can I live my life stepping on this stuff and not wonder at all? William Bryant
  3. 3. “Probably more harm has been done to soil science by the almost universal attempts to look upon the soil merely as a producer of crops rather than as a natural body worth in and for itself of all the study that can be devoted to it, than most men realize.” --- C. F. Marbut, 1920
  4. 4. A Rainbow of Soil A rainbow of soil is under our feet; Red as a barn and black as a peat. It’s yellow as lemon and white as the snow; Bluish gray. So many colors below. Hidden in darkness as thick as the night; The only rainbow that can form without light. Dig you a pit, or bore you a hole, you’ll find enough colors to well rest your soul. F.D. Hole, 1985
  5. 5. Soil is any naturally-occurring, unconsolidated (loose) material on the surface of the earth, which will support plant growth.
  6. 6. Soil • Basic resource sustaining all terrestrial ecosystems. • Soils are not a renewable resource in the scale of human lifetimes. • Most soil profiles are thousand of years in the making • In some regions of the world, human activities are destroying some soils faster than nature can rebuild/restore them
  7. 7. Soil performs 3 main functions: 1. Provide a medium for plant growth 2. Regulate and partition water flow through the environment 3. Serve as an environmental buffer a. Can hold nutrients and release them as required by plants b. Can also breakdown harmful compounds into substances that are not toxic to plants and animals (limited ability).
  8. 8. Soil is a product of: Parent material Climate Topography Biology Time Humans!
  9. 9. Influence of Parent (geological) Material Glacial deposition (Photo K.Murray) Glacial Action (Photo J.C.Miller) Soil formed on Glacial "Till" (Photo Dr.J.A.Robertson)
  10. 10. Fluvial materials – sorted by water
  11. 11. Aeolian materials – sorted by wind
  12. 12. Influence of Parent (geological) Material Bedrock (Photo A.R.Aandahl) Fluvial sediment (river deposits) (Photo A.R.Aandahl) Loess (wind deposits) (Photo A.R.Aandahl
  13. 13. Influence of Parent (geological) Material Tidal deposits (Photo J.C.Miller) Tidal landscape (Stewiacke River) (Photo J.C.Miller)
  14. 14. Influence of Climate (precipitation)
  15. 15. “Essentially, all life depends upon the soil ... There can be no life without soil and no soil without life; they have evolved together.” --- Charles E. Kellogg, USDA Yearbook of Agriculture, 1938
  16. 16. Soil Ecology The soil biological community can weigh from 1100 to 14000 kg/ha; a similar weight as 2 to 28 yearling steers! Over 1 billion microbes in 1 tsp of a fertile soil
  17. 17. Soil biology (soils.usda.gov/sqi/concepts/soil_biology/arthropods.html)
  18. 18. Earthworm burrows
  19. 19. Topographic (land shape) effects
  20. 20. Slope effects on soil serc.carleton.edu/details/images/12506.html
  21. 21. Ecosystems and biology
  22. 22. Ecosystem and biology Eastern Acid Forest Soil & Landscape (Podzol) Prairie Black Soil (Chernozem) (Photos - Agriculture Canada) (Photos - Agriculture Canada) Poorly drained soil (Gleysol)
  23. 23. “The nation that destroys its soil, destroys itself.” --Franklin Delano Roosevelt “Plowed ground smells of earthworms and empires.” --Justin Isherwood
  24. 24. Soil colour is related to organic matter content, iron oxides, and drainage.
  25. 25. Munsell soil color charts
  26. 26. • www.organicagriculture.co/
  27. 27. Soil organic matter Component Rate of decay • Serves as food for soil organisms • Stores and provides plant nutrients Decades • Enhances soil structure, porosity and water holding capacity Hundreds to • Holds nutrients (Cation thousands Exchange Capacity) of years • Stabilizes microaggregates Light fraction Weeks to months Physically protected Chemically stable Primary Function
  28. 28. Organic matter builds structure Sticky byproducts of decay Soil aggregation - organic "glue" binds mineral particles together
  29. 29. Soil organisms shape the soil Soil aggregation - burrowing organisms (S.S.S.A.) Worm castes (S.S.S.A.)
  30. 30. The stability of soil structure
  31. 31. Soil Minerals Clay Mineral Clay Mineral (Koalinite) Clay minerals - shrinkage & swelling
  32. 32. Soil Particle Size Classes Most Important Aspect of Soil Texture = SPECIFIC SURFACE. (Specific Surface = Total area on particle surfaces / total mass of particles) Separate Class Size (mm) # of particles per gram Specific Surface Coarse Sand 1 mm 400 22.5 cm2/gram Fine Sand 0.1 mm 400,000 225 cm2/gram Medium Silt 0.01 mm 400,000,000 2250 cm2/gram "Illite" Clay 0.0001-0.001 mm 7 x 1013 1,200,000 cm2/gram 4 x 1014 8,000,000 cm2/gram = 1/5 Acre = ave. house lot (per gram) "Montmorillonit 0.0001-0.002 mm e" Clay
  33. 33. Influence of soil separates on other soil properties (T.J. Rice, 2002) Property Water holding Aeration when moist Soil organic matter Organic matter decomp Warmup in spring Shrink-swell Compactability Water erosion risk Cation exchange cap. Resistance pH change Sand Low Good Low Rapid Rapid Very low Low Low Low Low Silt Med-high Med Med-High Med Med Low Med High Med Med Clay High Med-poor High - Med Slow Slow Mod-High High Low if aggreg. High High
  34. 34. Soil Structure (aggregation)
  35. 35. Factors influencing soil structure Soil aggregation wetting/drying & clay content Soil aggregation - Tillage
  36. 36. Andy’s favorite: Solodized Solonetic Soil (Found in the prairies)
  37. 37. Cation Exchange Capacity (CEC) CEC: The capacity of the soil to hold cations (positively charged molecules) Black – colloid of clays & humus with a negative charge, attract cations (+ ions). Molecules including nutrients in the soil come in the form of ‘ions’, molecules with a ‘+’ or ‘-’ charge: Cations (+): NH4+, Ca++, Mg2++, K+, Fe2++, H+, Al+++ Anions (-): HPO4-, SO4-, Cl-, HCO3-, HPO3--, OH-
  38. 38. Cation Exchange Capacity (CEC) Black – colloid of clays & humus with a negative charge, attract cations (+ ions). Dark blue - inner zone around the colloid has more cations (+) than anions (-). Cations within this zone are said to be "adsorbed", or "exchangeable". Light blue - The outer soil solution (lighter blue) has a balance of anions & cations. The cations within this zone are "free" to move with & within soil water.
  39. 39. Soil pH • pH: measure of the concentration of H+ in soil solution: pH = - log [H+] • Therefore, low pH value, means high H+ concentration, and more acidic • Higher concentration: – Acidic or sour – Corrodes metals – Bumps desirable cations off of soil exchange – Nutrient imbalance
  40. 40. “... only rarely have we stood back and celebrated our soils as something beautiful, and perhaps even mysterious. For what other natural body, worldwide in its distribution, has so many interesting secrets to reveal to the patient observer? ” --- Les Molloy, Soils in the New Zealand Landscape: the Living Mantle, 1988
  41. 41. dal.ca www.dal.ca Visit OACC.INFO for Production, research and market information Upcoming workshops & symposiums Virtual farm tours Organic award winners Organic policy toolbox Monthly e-zine
  42. 42. Visit • • • • • • OACC.INFO for Production, research and market information Upcoming workshops & symposiums Virtual farm tours Organic award winners Organic policy toolbox Monthly e-zine

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