SOIL PROFILE Soil genetic horizons HORIZON soil layer


























































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SOIL PROFILE

Soil genetic horizons -HORIZON: soil layer parallel to surface with characteristics produced by soilforming processes

3 basic soil units (scale) Pedon: smallest volume called a soil Polypedon: soil body (2 or more pedons) in which soils are relatively uniform Soil Series: groups of like polypedons

profile: one side of pedon, showing all horizons; 2 -D





Master horizons O A E B C R Not every soil has all of these!!!

O horizon Organic material Same as litter layer or “duff”

Oi slightly decomposed (litter) : FIBRIC Oe intermediate decomposition: HEMIC Oa highly decomposed : SAPRIC Oi Oe Oa


A horizon (“TOPSOIL”) § topmost mineral horizon accumulation of well-decomposed O. M. § Often bioturbated § surface horizon disturbed by plowing (Ap)

A horizon in grassland

Buried A horizon Ab


E horizon § LOSS of § silicate clay, Fe & Al oxides, humus by eluviation § carbonates, gypsum by leaching

Leaching vs. eluviation LEACHING : removal of soluble minerals (Ca, Mg, Na) in solution ELUVIATION : loss (by water) of suspended materials (clay, humus, oxides) ”emigrating”

E horizon § lighter color than A § Because the colorful humus and Fe, Al oxides have eluviated away § coarser texture than B § Because the clay eluviated away

E horizon in forest soil



B horizon ACCUMULATED (illuviated ) ”immigration” silicate clay, Fe & Al oxides, carbonates, gypsum, humus § § distinguished from A or E: § stronger, redder, or darker color § OR different texture


Bh Has illuviated humus from E (dark, brown or black stain at top of B) Bs Has illuviated sesquioxides of Fe, Al from E (reddish color at top of B) Bhs Has both


E Bhs

O A E Bh Bs

E Bhs Bw

Bhs

E A Bhs

A E Bhs Bw

Bt An accumulation of silicate clay in B Can recognize it if you have clay in the B but not as much clay in the A ; can see clay skins Called an “argillic” horizon



Bk Has precipitated carbonates in it; White nodules or streaks Strongly effervescent


w : used if you see a change in B that is not accounted for by other subhorizon letters Bw If you see changes in color, texture, structure within a B



C horizon § Mineral horizon (not bedrock) underlying A, E, B horizons § not affected by soil-forming processes § may be parent material


R horizon Consolidated rock

Transitional horizons Zone of transition between master horizons AB A B; A dominates BA A B; B dominates AC A C; A dominates EB E B; E dominates etc….


Mixed horizons One horizon scattered within another horizon B/A mixed A&B; B is matrix for A E/B E is matrix etc….


Numbers after letters Changes within master horizon for which there is no subhorizon designation e. g. , A 1 A 2 for color change within A


g ss o n Additional subhorizons that you will need to know:


g : gleying Wet; grey; below water table Bg

ss : slickensides Shiny surfaces on clay peds that have Rubbed against one another, polishing the surfaces

o : all Fe, Al oxides Red, tropical Bo

Bss In Agassiz clay

n : accumulation of sodium (Na) Usually found in dry grassland or arid regions

Identifying horizons in the field

some terminology… Colloidal : submicroscopic humus and clay are colloidal Humus: ultimate stage of organic decay predominately protein, gums, lignin Sesquioxides: 1½ oxygens for each Fe, Al sesquioxides of Fe, Al: Fe 2 O 3 Al 2 O 3
O a e b c r horizons
Soil horizons
B horizon
Oaebcr
Soil horizons
Oaebcr soil
Desert soil formation
Evolutionary drift
What is the difference between genetic drift and gene flow
Genetic programming vs genetic algorithm
Genetic programming vs genetic algorithm
What is the difference between genetic drift and gene flow
Components of soil pie chart
Soil compaction ppt
Soil characteristic
Soil horizon
Soil horizon parent material
Soil food web horizon
Difference between silt and clay
Soil health
Regolith
Soil horizon parent material
Secure socket layer and transport layer security
Pharynx
Secure socket layer and transport layer security
Layer-by-layer assembly
Secure socket layer and transport layer security
Secure socket layer and transport layer security
Layer 2 vs layer 3 bitstream
Presentation layer functions
Layer 2 e layer 3
Pigmented layer and neural layer
Latosol soil profile
What is the
Soil profile is a vertical cross section
Bedrock
Brown earths
Soil profile
Puising
Podzol soil profile
Soil profile
Clay soil profile
Brown earth soil profile diagram
Latosol soil characteristics
Part of the soil
Deepest layer of soil
What is c called
Archaeological dating
Diagnostic horizons
Explorer de nouveaux horizons
"horizons"
Bright horizons backup care advantage
3 horizons of innovation
Topmost mineral horizon
Spodic horizon
Elluviation
Pennine horizons digital archive
Bright horizons ucsf
Xxzoox