ENST200 Exam 1 - excluding soil taxonomy
Soil texture - correct answer sizes of the soil particles, combination of clays, silts, and sands
Munsell color chart - correct answer standardized coloring system for soils with three
components: hue, value, chroma
Hue - correct answer redness or yellowness of the soil, changes from one page to another
Value - correct answer lightness or darkness (0= black), increase bottom to top
Chroma - correct answer Intensity or brightness (0=neutral gray), increase left to right
How to read/state a color - correct answer (hue)YR (value)/(chroma)
3 major causes of soil color - correct answer organic matter content, water content, presence
of oxidation states of iron and manganese oxides in various minerals
how does organic matter effect soil color - correct answer darkens soil, masks bright colors,
coats mineral aprticles
how does water content effect soil color - correct answer soils are darker when they are wet
than when they're dry, also indirectly effects color by influencing oxygen levels and rate of
organic accumulation, influences oxidation state of Fe + manganese
Well oxidized iron soil color - correct answer bright reds and browns
manganese oxides soil color - correct answer black
glauconite soil color - correct answer green
calcite and other soluble salts soil color - correct answer whitish-gray
reduced iron soil color - correct answer gray and blueish color
removal of reduced iron soil color - correct answer light gray
Gleying - correct answer gray color in soil due to reduced iron and/or iron depletion
Sand size - correct answer smaller than 2 mm, larger than 0.05mm, largest textural size
properties of sand - correct answer gritty, visible to the naked eye, rounded or angular, most
grains consist of a single material (usually quartz), contain few plant nutrients, large pores,
rapid drainage, poor water holding capacity, not sticky
Characteristics of sandy soils - correct answer well aerated and loose, infertile, prone to
drought
Silt size - correct answer smaller than 0.05mm but larger than 0.002mm
, silt properties - correct answer smooth and silky, large surface area, significant release of plant
nutrients, smaller pores, retains water, not very sticky or plasticky
Clay size - correct answer less than 0.002mm
Clay properties - correct answer large surface area, high capacity for absorption, cohere in hard
mass after drying, easily molded when wet, behave as colloids, hold a lot of water, shaped like
tiny flakes or flat platelets
Influence of particle surface area on soils - correct answer increased SA = increased capacity for
holding water, increased capacity to retain nutrients and chemicals, increased rate of release of
plant nutrients from weatherable minerals, increased propensity for particles to stick together,
more microbial action
What are the 14 textural classes (coarse to fine)? - correct answer sand, loamy sand, sandy
loam, fine sandy loam, very fine sandy loam, loam, silt loam, silt, sandy clay loam, silty clay
loam, clay loam, sandy clay, silty clay, clay
Loams - correct answer mixture of sand, silt, and clay, exhibits properties of the three in equal
proportions (not equal amounts)
Alteration of soil textural classes - correct answer relatively permanent feature of a soil, only
altered by pedologic processes over very long periods of time, when trying to artificially change
texture great care must be exercised
components of soil structure - correct answer complex pores and channels, how the particles
come together, microbial glues, roots, and fungal hyphae
Soil structure - correct answer spatial arrangement of particles to form complex aggregations,
pores, and channels
Ped/aggregate - correct answer structural units formed when silt, sand, clay and organic matter
are aggregated together
What is structure influenced by? - correct answer freeze-thaw, wet-dry, shrink-swell,
penetration and swelling of plant roots, burrowing of soil animals, activities of people and
machines
What influence do pores have on soil? - correct answer movement of air and water, root
growth, activities of organisms, accumulation and breakdown or organic matter
Single grained soil structure - correct answer particles are not aggregated
Massive structural condition - correct answer large, cohesive masses
4 principle shapes of soils - correct answer Spheroidal, platy, prism-like, block-like
Soil texture - correct answer sizes of the soil particles, combination of clays, silts, and sands
Munsell color chart - correct answer standardized coloring system for soils with three
components: hue, value, chroma
Hue - correct answer redness or yellowness of the soil, changes from one page to another
Value - correct answer lightness or darkness (0= black), increase bottom to top
Chroma - correct answer Intensity or brightness (0=neutral gray), increase left to right
How to read/state a color - correct answer (hue)YR (value)/(chroma)
3 major causes of soil color - correct answer organic matter content, water content, presence
of oxidation states of iron and manganese oxides in various minerals
how does organic matter effect soil color - correct answer darkens soil, masks bright colors,
coats mineral aprticles
how does water content effect soil color - correct answer soils are darker when they are wet
than when they're dry, also indirectly effects color by influencing oxygen levels and rate of
organic accumulation, influences oxidation state of Fe + manganese
Well oxidized iron soil color - correct answer bright reds and browns
manganese oxides soil color - correct answer black
glauconite soil color - correct answer green
calcite and other soluble salts soil color - correct answer whitish-gray
reduced iron soil color - correct answer gray and blueish color
removal of reduced iron soil color - correct answer light gray
Gleying - correct answer gray color in soil due to reduced iron and/or iron depletion
Sand size - correct answer smaller than 2 mm, larger than 0.05mm, largest textural size
properties of sand - correct answer gritty, visible to the naked eye, rounded or angular, most
grains consist of a single material (usually quartz), contain few plant nutrients, large pores,
rapid drainage, poor water holding capacity, not sticky
Characteristics of sandy soils - correct answer well aerated and loose, infertile, prone to
drought
Silt size - correct answer smaller than 0.05mm but larger than 0.002mm
, silt properties - correct answer smooth and silky, large surface area, significant release of plant
nutrients, smaller pores, retains water, not very sticky or plasticky
Clay size - correct answer less than 0.002mm
Clay properties - correct answer large surface area, high capacity for absorption, cohere in hard
mass after drying, easily molded when wet, behave as colloids, hold a lot of water, shaped like
tiny flakes or flat platelets
Influence of particle surface area on soils - correct answer increased SA = increased capacity for
holding water, increased capacity to retain nutrients and chemicals, increased rate of release of
plant nutrients from weatherable minerals, increased propensity for particles to stick together,
more microbial action
What are the 14 textural classes (coarse to fine)? - correct answer sand, loamy sand, sandy
loam, fine sandy loam, very fine sandy loam, loam, silt loam, silt, sandy clay loam, silty clay
loam, clay loam, sandy clay, silty clay, clay
Loams - correct answer mixture of sand, silt, and clay, exhibits properties of the three in equal
proportions (not equal amounts)
Alteration of soil textural classes - correct answer relatively permanent feature of a soil, only
altered by pedologic processes over very long periods of time, when trying to artificially change
texture great care must be exercised
components of soil structure - correct answer complex pores and channels, how the particles
come together, microbial glues, roots, and fungal hyphae
Soil structure - correct answer spatial arrangement of particles to form complex aggregations,
pores, and channels
Ped/aggregate - correct answer structural units formed when silt, sand, clay and organic matter
are aggregated together
What is structure influenced by? - correct answer freeze-thaw, wet-dry, shrink-swell,
penetration and swelling of plant roots, burrowing of soil animals, activities of people and
machines
What influence do pores have on soil? - correct answer movement of air and water, root
growth, activities of organisms, accumulation and breakdown or organic matter
Single grained soil structure - correct answer particles are not aggregated
Massive structural condition - correct answer large, cohesive masses
4 principle shapes of soils - correct answer Spheroidal, platy, prism-like, block-like
