Field Experience in Soil Inventory Methods (Treehaven)

NRES 360

Till

unsorted parent material encompassing clay to boulders (moderate permeability and medium water holding capacity)

Drumlins

elongated, stretched, tear drop-shaped hills of till (unsorted) facing the same direction in a group

Outwash

sorted sand and gravel parent material deposited by glaciers (flowing meltwater), leaving thick/non-uniform layers (rapid permeability and low water holding capacity)

Kame

isolated glacial geology formed from waterfall flowing over ice and through crevasse, depositing sorted gravel material

Kettle

chunk of ice from glacier melted and left depression on the landscape

Lacustrine

lake deposit that is sorted, fine-textured sand/silt/clay, and has thin layers (slow permeability and high water holding capacity)

Moraine

glacier pushed material

Esker

snake-shaped hill of gravel, formed by “river” under ice

Erratic

boulders riding along in glacier were deposited erratically

Spodisols

dark brown/reddish subsoil with organic matter accumulation and no clay

Entisols

Soils that have little or no development of pedogenic horizons

• Thin A, E, or peaty horizons

• Alluvial soils

• Steep soils

• Eroding dune sands

• Sandy soils with a weak A and a “color" B”

  • Simple wetland soils

Aquents (Entisols)

Wet entisols

• Gray and mottled

• Very thin A horizon

• May be brown

Fluvents (Entisols)

Not usually wet and are not sands

• Soils developing in stratified stream deposits (alluvium)

• May be periodically flooded

Psamments (Entisols)

Formed in well-drained, sorted sands

Inceptisols

Weakly developed horizons with structure and/or gleying but little/no clay or spodic material accumulation

Aquepts (inceptisols)

Wet (surface soil dark over mottled gray with maybe pedal/blocky structure)

Ochrepts/Udepts (inceptisols)

Not usually wet

Mollisols

Deep, dark A horizons that are relatively fertile

Aquolls (mollisols)

Wet and deep dark-colored surface soil over olive-gray redox featured subsoil

Udolls (mollisols)

Not usually wet

Aquods (spodosols)

Wet

Orthods (spodosols)

Not usually wet (fragipan may underlie spodic horizon)

Alfisols

Thin A horizons and definite E horizons with subsoils in which clay accumulation is distinct

Histosols

Peaty and mucky soils more than 40 cm thick and wet (no less than 20-30% organic matter by mass)

Fibrist (Histosol)

Fibrous with original plant fragments (moss/sedge) clearly visible

Hemist (histosol)

Partially fibrous with original plant fragments broken down to a black/brown paste

Saprist (histosol)

Almost without fibers in a fine black/brown amorphus material

Aeolian

silty and fine sand parent material deposited by wind (thick layers)

O horizon

Organic surface layer with little mineral soil material

A horizon

Mineral soil horizon darkened by presence of humusA

Ap

Plow layer (topsoil broken up into small granular pieces) or other disturbance

E horizon

Lighter colored/gray eluvial (leached) layer

B horizon

Subsurface horizon ranging from brown to dark reddish brown (coatings of illuvial humus and sesquioxides)B

Bt

silicate clays leached into subsurface B horizon

Diagnostic argillic horizon

clay (associated with deciduous forest)

C horizon

unconsolidated soil material, relatively unaltered material

R horizon

Bedrock

Bw

weak horizon, not fully developed,

Bs

Illuvial accumulation of sesquioxides and humus (immediately beneath O/A/E horizon

Bh

Illuvial accumulation of humus, usually combined with s

Bx

indicates fragipan

Fragipan

dense subsoil horizon that is brittle (fragic) when moist and hard when dry

g

strong gleying indicating iron reduced/removed (redox depletion) showing blotches of gray and rusty colors

Redox depletions

gray zones

Redox concentrations

rusty zones

Sapric

most highly decomposed organic material (fiber content less than 17%)

Hemic

organic material of intermediate decomposition (fiber content 17-40%)

Fibric

least decomposed organic material (fiber content more than 40%)

4 types of epipedons…

Mollic, Umbric, Ochric, Histic

Mollic Epipedon

dark colored, humus enriched, mineral horizon at least 18-25 cm thick (commonly found under grassland native vegetation(

Umbric Epipedon

dark colored, humus enriched, mineral horizon at least 18-25 cm thick (commonly found under grassland native vegetation) PLUS have <50% base saturation and pH values <5.5

Ochric Epipedon

all the surface mineral horizons failing to meet any of the requirements of mollic or umbricHis

Histic Epipedon

shallow bog on top of mineral soil, 20-40cm thick in wet areas

Diagnostic subsurface horizons (5)

Albic horizon, Argillic horizon, Spodic horizon, Cambic horizon, Fragipan

Albic (diagnostic subsurface horizon)

leached horizon with a white/gray color

Argillic (diagnostic subsurface horizon)

Illuvial horizon with an accumulation of silicate clays

Spodic (Diagnostic subsurface horizons)

accumulation of organic matter, aluminum, iron oxides (illuvial horizon found below an eluvial E horizon)

Cambic (diagnostic subsurface horizon)

subsurface horizon with a texture finer than loamy fine sand without strong weathering/humus

Transitional horizon types (2)

1) distinct volumes of 2 different horizons in the same transition zone (E horizon tongues down into a Bt horizon)

2) distinct volumes of 2 different volumes of 2 different horizons