Soils Test 2

Human-modified, mollic-like, high in P

Organic horizon, saturated for less than 30 days per normal year

Very high in organic content, wet during some part of the year

Thick, black, high in organic matter (>6% organic C), common in volcanic ash

• Prairie soils
• Thick, dark-colored, high base saturation (>50%), strong structure

Too light-colored, low organic content or thin to be Miollic, may be hard and massive when dry

Human-made sodlike horizon created by years of manuring

Same as Mollic except low base saturation (<50%)

Organic and clay accumulation just below plow layer (6-8")

Light-colored, clay and Fe and Al oxides mostly removed

Silicate clay accumulation

Accumulation of CaCO₃ or CaCO₃*MgCO₃

Changed or altered by physical movement or by chemical reactions, generally nonilluvial

Hard pan, strongly cemented by silica

Brittle pan, usually loamy textured, dense, coarse prisms

Whitish eluvial horizon that tongues into a Bt horizon

Accumulation of gypsum

Accumulation of low-activity clays

Argillic, high in sodium, columnar or prismatic structure

• Tropical
• Highly weathered, primarily mixgture of Fe, Al oxides and nonsticky-type silicate clays

Cemented clacic horizon

Cemented gypsic horizon

Thin pan cememnted with iron alone or with manganese or organic matter

Accumulation of salts

Organic matter accumulation

Organic matter, Fe and Al oxide accumulation

Highly acidic with Jarosite mottles

artificial (human-made)

23,040

• 36
• 1 square mile each
• 1 square mile = 640 acres

• Order
• Suborder
• Great Group
• Subgroup
• Family
• Series
• Soil Phase

Surface horizons

subsurface horizons

A subdivision of the series, it narrows down properties used in farm planning

• recent soils
• no naturally formed horizons (or just beginning)
• Ent

• Inverted soils
• high content of swelling clays
• ert

• beginning soils
• master horizons dominate
• mild weathering, various conditions
• ept

• soft, dark soils
• must have Mollic epipedon
• 50% base saturation
• semi-arid to moist grasslands
• oll

• moderately weathered soils
• argillic/natric diagnostic horizon
• >35% base saturation (no mollic, oxic, spodic horizon)
• mildly acid
• alf

• old weathered soils
• most soluble materials leached out
• argillic horizon <35% base saturation
• (strongly acid clays)
• Ult

• Dry soils
• orchic epipedon
• usually high in salts
• id

• Ash colored soils
• must have a spodic horizon
• humid climates
• od

• organic soils
• high organic matter
• water-saturated conditions
• measured by amount of decomp
• histic epipedon
• ist

• frozen soils
• ice or permafrost
• el

• ando-like soils
• volcanic ash materials
• not much profile development
• and

• oxide soils
• oxic horizon
• tropical soils
• ox

entisol

vertisol

inceptisol

aridisol

mollisol

spodosol

alfisol

ultisol

oxisol

histosol

andisol

gelisol

a vertical section of the soil through all its horizons and extending into the parent material

a layer of soil, approximately parallel to the soil surface, differing in properties and characteristics from adjacent layers below or above it

having lost all or part of the upper soil horizon or horizons

horizons having specific soil characteristics that are indicative of certain classes of soils. horizons that occur at the soil surface are called epipedons. those that occur below the surface are diagnostic subsurface horizons

a soil layer or horizon in which material carried from an overlying layer has been precipitated from solution or deposited from suspension. The layer of accumulation.

the removal of soil material in suspension from a layer or layers of a soil. usually, the loss of material is described by the term leaching.

• a mapping unit used in detailed soil surveys where two or more defined taxonomic units are so intimately intermixed geographically that it is undesirable or impractical, because of the scale being used, to separate them.
• Ocie-Gepp-Gatewood complex

• grouping of soils found together in a geographical area
• consists of 2 or more soil series
• Creldon-Hoberg-Burden Association

a group of soils that commonly occur together in a landscape, each characterized by a different slope position and resulting set of drainage-related properties

the smallest volume that can be called a soil. it has three dimensions. it extends downward to the depth of plant roots or to the lower limit of the genetic soil horizons. its lateral cross section is roughly hexagonal and ranges from 1 to 10 m² in size depending on the variability in the horizons.

• not limited to 2mm diameter
• fine-silty, loamy, coarse loamy, clayey, skeletal, etc.

• dominant clay in system
• kaolinitic,, montmorellonitic, mixed, etc.

semiactive, active, superactive

• frigid<8C, 46F
• messic - 8-15C, 46-59F
• thermic - 15-22C, 59-72F
• hyperthermic - above 72, 22C

acidic, calcareous, neutral

shallow

Soil Phase

• Soil phase
• 5 randomly assigned numbers

Land Capability Classification System

few, if any limitations on land use (good crop land)

• row crop cultivation
• 2-3 more sloped than 1

marginally suited for cultivation

• limitation is something other than slope
• frequent overflow, large rocks or boulders

• several use limitations
• 6-7-8 increasing slopes
• 8, maybe watershed areas, aesthetic values

• e - erosion hazard
• w - water
• s - soil limitation (usually impermeable layer)
• c - climatic factor

• metes and bounds
• creeks, fored road, trees

• Quadrant/Putnam
• Rectangular survey system based on areas with square corners

• North - South
• T1N, T2N, T3N, principal meridian, T1S, T2S
• 6 mile intervals

• Runs East-West
• Base line is in Arkansas, south of Little Rock
• R29W, R28W, R20W...

36m²

160

lower the value, grayer the soil

• 0= absolute black
• 10=no black

the shape of soil agregates

long axis parallel to the surface (kind of oval shaped)

rounded

• corners may be rounded, but sort of cube-shaped
• more blocky as clay content increases

• almost perfect cube shaped
• faces flat, edges sharp

flat tops, axis perpendicular to the soil surface. like little towers.

axis perpendicular to the soil surface but rounded tops

granular, subangular, angular blocky

extremely high clay content and particles fuse together

when the plow or till can break it apart easily

O

• O1 - Oi, Oe
• O2 - Oa, Oe

A

A

Two capital letters

A

E

AB or EB

E/B

AC

B

BA or BE

• B or Bw
• Only use Bw when no other subordinate is appropriate.
• So if we have B2t, what do we use? Bt2

BC or CB

By using a number in front of the capital letter