Soil Science Exam 1

Colluvium

Parent material deposited by gravity. Not well sorted or fertile

Alluvium

Water deposition as water spread and slows during flooding, well sorted sediment. Fertile. Rivers

Marine sediment

coastal plains, ocean sediment, well sorted

Lacustrine sediment

Lake. High in clay. Major parent in glaciated areas(not here)

Eolian

Wind. Sand dunes volcanic ash.

Loess

Silt carried by wind

Aquic

Wettest climate regime

Udic

Alabama’s soil moisture regime

Ustic

Dryer than Udic

Aridic

Dry

Xeric

CA/Mediterranean. Moist winters/dry summers

Cryic

Coldest

Frigid

Not as cold as cryic

Mesic

Middle soil temp regime

Thermic

Alabama. Hotter

Hyperthermic

Hottest

5 soil forming factors?

Climate

Landscape(topography)

Organisms(Biological)

Parent Material(colluvium etc.)

Time

Master Horizons

O - Organic

A - Mineral horizon. topsoil, darker

E - Eluviation. Often lighter

B - Illuviation. Accumulation. Darker/heavier(clay)

C - Parent material

R - Bedrock

Subordinate distinctions

G - Gley or mottling (grey color of we soils)

k - accumulation of carbonates

p - plow depth.

w - distinctive color or structure

t - accumulation of silicate clays

r - weathered or soft bedrock

Diagnostic subsurface horizons

Argillic - accumulation of clay

Natric - accumulation of salts

Spodic - Al oxides and OM, illuvial horizon

Kandic - low acidity clay, highly weathered

Albic - Eluvial horizon. Fe oxides and clay have been removed. light colored

Oxic - Highly weathered subsurface. Humid tropics/subtropics. HERE

Placic - thin black to dark reddish Fn, Mn, or Fe humus-centered pan

Cambric - little development, some color or structure

12 soil orders

Alfisol(alf) - argillic, natric, or kandic horizon. high-med base saturation

Andisol(and) - volcanic

Aridisol(id) - dry, ochric epipedon

Entisol(et) - little profile development, ochric. often deposited by rivers. Youngest

Gelisol(el) - permafrost

Histosol(ist) - peat or bog soil(organic)

Inceptisol(ept) - Embryonic soil with little features, ochric or umbric. Slightly older than entisol

Mollisol(mol) - Mollic epipedon, dark high in bases

Oxisol(ox) - oxic horizon, no argillic, highly weathered

Spodisol(od) - spodic horizon with iron/al oxides

Ultisol(ult) - argillic or kandic horizon, low base saturation. ALABAMA

Vertisol(ert) - high in swelling clays. deep cracks when wet.

What 2 diagnostic epipedons are associated with humans?

Antrophic and Plaggen

Which 2 diagnostic epipedons are associated with organics?

Histic, Fostic

Sumpter clay

ALABAMA

Aquent

Wet entistol

alb

suborder. albic horizon(bleached elluvial)

Spodisols

northeast

What kind of soils are “shrink and swell”

Vertisols

aqu

suborder. wetness

arg

suborder. presence of argillic horizon (illuvial clay)

bor

suborder. cool

fluv

suborder. floodplains

ochr

suborder. ochric epipedon

psamm

suborder. sand texture

torr

suborder. usually dry

ud

suborder. humid climate (udic)

ust

suborder. drier climate (ustic)

xer

suborder. annual dry season(xeric)

What part of the nomenclature is MOST important when reading

Order. ending of name. alf, oll, ent, etc.

For this course, color of soil will be what kind of property?

Physical

What are the main pigments in soil?

Organic matter, Fe, Mn

Describe a mottled soil

Alternates wet and dry, causing a mix of red and gray

What is used to measure soil color

Hue, value, chroma

Hue

Dominant spectral rainbow color. The PAGE in the Munsell book

Value

Relative lightness of the color, function of the total amount of light. Column in the book

Chroma

Relative purity/strength. Row in the book

What does a grey soil color indicate?

Poor drainage

Mollisol

Order. High organic matter, high fertility. Likely grassland

What are some rules to using the Munsell color book?

Back to the sun, no sunglasses

How does redox affect soil color

Darker, red

Do we have scientific and proven ways of measuring soil color that are being adopted?

No, there are some apps that can measure soil moisture but not soil color.

Sand size class

2.0 - 0.05mm in diamter

Silt size class

0.05 - 0.002mm in diameter

Clay size class

Less than 0.002mm in diameter

What is soil texture defined by?

Percentage of sand, silt, and clay by weight. Organic matter is not part of the measurement

In what application(s) would we create a preferred soil texture?

Potted plants, shrubs, transplants, putting greens, athletic fields

If you want a lawn to drain quickly, what kind of soil would you want? (Think texture)

Sandy

Infiltration

Ability for water to enter and absorb into soil. Sponge.

Loam

1/3 sand, silt, and clay

More organic matter —> better granular structure

Granulars are almost always associated with what kind of soil horizon?

Surface A horizon

What kind of soil structure has poor drainage and is common around poorly managed croplands?

Platy

In what soil horizon would you find a structureless condition?

C horizon

What kind of soil structure are you likely to find in the B horizon?

Blockly, both sub-angular and angular

What kind of soil structure typically has a salt cap on top

Columnar maybe prismatic.

Alfisol

Alf. Order. argillic, natric, or kandic horizon. High-med base saturation. Generally weathered and fertile

Andisol

And. Order. Volcanic

Aridisol

And. Dry, ochric epipedon

Entisol

Ent. Order. Young, not much weathering or development. Generally found in river deposits. Ochric epipedon

Gelisol

Ell. Order. Permafrost. Frozen

Histosol

ist. Order. Organic matter. peat or bog soil

Inceptisol

Ept. Just older than entisols. Embryonic soil with few features. Ochric or umbric epipedon. Cambric horizon

Mollisol

Oll. Order. Mollic epipedo. Dark, high in bases, feritle productive soils

Oxisol

Ox. Order. Oldest order. No argillic, highly weathered

Spodosol

Od. Order. Spodic horizon with iron/Al oxides

Ultisol

Ult. Order ALABAMA. Argillic or kandic horizon. Low base saturation. Productive soils

Vertisol

Ert. Order. Swell shrink clays. deep cracks when wet.

When naming soils, which part is the most specific. Least?

Series, order.

How many diagnostic epipedons are there?

8

Mollic

Diagnostic epipedon deep, dark, high in bases, fertile and productive soil

What are the different kinds of transported parent material? (we went over 5)

Colluvium, Alluvium, Eolian, Lacustrine/marine, glacial

What horizons are diagnostic epipedons a part of?

Surface

Umbric

Diagnostic epipedon. Same as mollic but LOW in bases

How do umbric and mollic epipedons differ?

Mollic is higher in bases

Ochric

Too thin, too light, or too low in bases to be considered mollic or umbric. Not much going on

Melanic

Diagnostic Epipedon. Volcanic

Histic

Diagnostic epipedon. Organic

Fostic

Diagnostic epipedon. Organic, but not as much as histic

Antropic

Diagnostic Epipedon. Human modified mollic-like

Plaggen

Diagnostic Epipedon. human made from years of manuring

Illuvial

Typically B horizon. Materials deposited here

Eluvial

E horizon. Water washes out material and what is left is the E horizon

Argillic

Subsurface horizon. accumulation of clay

Natric

subsurface horizon. accumulationof salts

Spodic

subsurface horizon. accumulation of al oxides and OM, illuvial horizon

Kandic

subsurface horizon. low acidity clays, highly weathered soils

Albic

subsurface horizon. eluvial horizon(E). Fe oxides and clay have been removed, light colored.

Oxic

subsurface horizion. highly weathered. humid tropic/subtropics. HERE. Oldest

Placic

subsurface horizon. thin black to dark reddish. Fe, Mn, or Fe humus-cemented pan

Cambric

subsurface horizon. little development. some color or structure.