Soil properties Flashcards
(62 cards)
What direct effect does color have on behavior or use of soil?
Soil warming in spring (the darker the soil the faster it warms)
Importance of soil color
Provides valuable clues to the nature of other soil properties (as well as classification)
Hue
Designates the color (number on top of page)
Value
designates the lightness of color (number on side of page)
Chroma
Distinguishes pure hue from a gray shade (number on bottom of page)
Main factors influence on soil color
- Water content
- Organic matter
- Oxidation state of iron and manganese/Magnisum
Black - Dark Brown (10Yr 2/1)
High organic matter
Reds and yellows
Ferric Iron (Fe^3+) oxides and hydroxides
Hematite
red (intense weathering) (5R 3/6)
Goethite
Yellowish brown (10YR 8/6)
Limonite
Yellow (humid environments)
Ferrihydrite
dark red (2.5 YR 3/6)
Gray and Bluish
Reduced iron compounds and poorly drained soils
Black (10YR 2/1) (Little Organic material)
Manganese Oxides
Greenish
Glauconite
White/Gray (10YR 6/1)
Quartz and silicate minterals
Whites (10YR 8/2)
Carbonate accumulation calcites, and soluble salts
How does chemical reduction affect soil color and under what conditions does it occur?
ferric iron oxides to mobile ferrous iron
results in gray colored soils
Why is texture considered a “basic soil property”?
does not change
Relationship between particle size and surface area
Larger particle = lower surface area
What does soil surface area influence in the soil?
Water holding capacity, chemical reactions, soil cohesion, cation exchange capacity, ability to support microorganisms
Teton dam
Failure to pay attention to soil properties. Seepage of water into an area with poor sealing like sand or silt.
Aggregates
Sand, silt, and clay particles when they are not independent of each other
Microaggreates
Comprised of smaller particles (2-250 micrometers)
