Soil Quiz 1 Flashcards
Father of modern soil science
V.V. Dokuchaev
Came up with Pedology
V.V. Dokuchaev
“The great communicator”
Konstantin D. Glinka
Father of modern soil survey
Curtis fletcher Marbut
Wrote “Factors of Soil Formation”
Hans Jenny
developed the four soil forming processes and worked on soil behavior and soil classification
Roy Simonson
Soil
- a dynamic body composed of mineral and organic solids, gases, liquids, and living organisms which can serve as a medium for plant growth
- The collection of natural bodies occupying part of the Earth’s surface that is capable of supporting plant growth and that has properties resulting from the integrated effects of climate and living organisms acting upon parent material, as conditioned by topography, over periods of time
soil descriptions (horizon, etc.) based on?
field observations only
Main soil horizons:
O, A, E, B, C, R
solum
surface and subsurface layers that are affected by soil formation
Horizons in solum
O, A, E, B
O horizon
organic material
A horizon
Humidified OM mixed with mineral fraction
Horizon that exhibits effects of cultivation, pasturing, and other similar disturbance
A horizon
Eluviated zone horizon
E horizon
E horizon
-mineral horizon, zone of eluviation
E horizon color?
Albic: white color
E horizon loss:
silicate clay, iron, aluminum, or a combo
E horizon remain:
sand, silt, quartz, other resistant materials
Illuviated zone horizon
B horizon
B horizon has a concentration of?
soluble salts, silicate clays, iron and aluminum oxides, and humus (alone or in concentration)
B horizon structure:
blocky or prismatic structure
What gives the B horizon a darker, richer, or redder color?
presence of iron and aluminum oxide coatings
C Horizon
- unweathered parent material
- Mineral horizon
- relatively unaffected by biological activity
- parent material can be alike or different than the solum above it
R Horizon
Hard Bedrock
R Horizon Hard Bedrock includes:
granite, basalt, quartzite and indurated limestone or sandstone that is sufficiently coherent to make hand digging impractical
1 inch of soil takes ____ years to form.
1,000
Transitional Soil Horizons: AB
- Dominated by properties of one master horizon but has subordinate properties of another
- First letter designates which master horizon has dominant properties in the horizon
- 2 capital letters
Transitional Soil Horizons: A/B
- “Virgule”
- Horizon has distinctly recognizable properties of both master horizons.
- The first symbol is that of the horizon that makes up the greater volume
- A/B has more volume of letter in front, not just distinct properties
Subordinate distinctions
- Lowercase letters are used to identify components present in significant amounts
- Found after the Master Horizon capital letter
- Example: Ap horizon (p= plow layer)
can every subordinate distinction go with every main horizon?
no
The Prime (‘)
- signifies a split horizon
- not enough for a subdivision
Lithologic discontinuities
- A change in particle size or mineralogy that existed prior to soil formation
- The number in front signifies the change in lithology
- Massive change, break in formation
- Ex: glacial effects
- Not the same throughout the whole profile
Soil has 6 key roles (ecosystem services):
- Support plant growth
- Regulate water supplies
- Functions as nature’s recycling system
- Habitat to living organisms
- Influence atmospheric conditions
- Engineering medium
Pedon
smallest volume that can be called a soil
Environmental Services- Support plant growth:
- physical support
- air
- water
- temperature moderation
- protection from toxins
- nutrient elements
Nutrient elements
C HOPKNS CaFe ClZn; MoB CuMn Mg
Environmental Services- regulation of water supplies
- infiltration
- lateral flow
- through flow
- filters water
Pedosphere
interaction of four spheres
“Clorpt”
*Soil Formation* Climate Organisms (biota) Relief (topography) Parent material Time
How many steps needed to form a soil?
11
supporting higher plant life
pedological view that this is where we begin seeing soil profiles, morphology
Assumptions in soil formation:
- closed system
- no human influence
- consistent climate
- variation in type and intensity of biota
- effects of variable parent material
Eluviation
loss, translocation
Illuviation
addition, translocation
leaching
loss, translocation, and in some situations, transformation
Erosion
loss, translocation
cumulization
addition, translocation
calcification
addition, translocation
decalcification
loss, translocation
salinization
addition, translocation
desalinization
loss, translocation
alkalization
addition, translocation
dealkalization
loss, translocation
lessivage
translocation; physical movement of clay
pedoturbation
translocation; mixing of the soil through biological activity
decomposition
transformation
synthesis
transformation
melanization
transformation
littering
additions
humification
addition, transformation
mineralization
transformation
gleization
transformation
Parent materials
residuum, colluvium, alluvium, lacustrine, marine, glacial till, glacial outwash, glacial moraine, aeolian, organic
What minerals are resistant to weathering?
silicate minerals
What works with O to create oxides (red v. gray)?
Fe and Al
What “bases” weather quickly?
Ca, Mg, Na, and K
Minerals:
- Naturally occurring inorganic substances that have a specific chemical composition and structural arrangement
- Made up of elements
Rocks:
Mixtures of minerals occurring in various proportions
Primary minerals:
- From under conditions different than those at Earth’s surface
- Often formed by solidification of magma
Secondary minerals:
- Mineral which forms at or near Earth’s surface
- Often formed from weathering products of primary minerals
Physical properties for identifying minerals:
- Hardness
- Luster
- Streak
- Color
- Density
- Crystal systems
- Cleavage and fractures
- Transparency
- Special Properties
Most important physical properties for identifying minerals?
- Hardness
- Luster
- Streak
- Cleavage and fractures
Why do soil scientists care about rocks and minerals?
- Contributes to Pedology
- Most parent materials were rocks at some point in their lives
- Minerals continue to contribute to soil fertility long after the rocks are gone
- Minerals provide volume and mass to soil
What charge (+ or -) does soil have?
negative
Minerals: hardness
- Minerals resistance to being scratched, but not same as brittleness.
- Use of Mohs scale (1 to 10), where 2 is softest and 10 is hardest.
Minerals: Luster
- Describes how light reflects from the mineral
- Metallic: shines like metal
- Non-metallic: greasy, earthy, pearly
- Terms: dull, pitchy, resinous, submetallic
Minerals: Streaking
- Color of the powder left when mineral is scratched on unglazed tile
- Mineral’s true color
- Dark streak suggests metallic; light streak suggests non-metallic
Cleavage
tendency for mineral to break along smooth planes parallel to zones of weak bonding
Fracture
tendency for mineral to break along curved surfaces without a definite shape.
Specific minerals to know:
calcite, dolomite, feldspar, fluorite, gypsum, hornblende, pyrite, hematite, biotite, magnetite, quartz, muscovite
What other mineral is magnetic, other than magnetite?
Hematite
Fertilizer minerals
calcite and dolomite
slow release fertilizer
dolomite
How do you test which fertilizer mineral is which?
Pour acid on them, will have a slow or fast reaction
