SOIL PROFILE Soil genetic horizons HORIZON soil layer
- Slides: 58
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
A E 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
- Master horizons
- Soil horizons
- O a e b c r soil
- Oaebcr
- Soil horizons
- Oaebcr soil
- Desert soil formation
- Genetic programming vs genetic algorithm
- Genetic programming vs genetic algorithm
- A gene pool consists of
- Genetic drift vs flow
- Genetic drift vs genetic flow
- Why is soil a nonrenewable resource
- Soil formation
- Soil food web horizon
- A horizon soil
- Soil health
- Regolith soil horizon
- Soil horizon parent material
- Soil horizon foldable
- Soil structure ppt
- Transition area between soil and parent material
- Pathway of food from mouth to anus
- Secure socket layer and transport layer security
- Layer-by-layer assembly
- Secure socket layer and transport layer security
- Layer 2 vs layer 3 bitstream
- Secure socket layer and transport layer security
- Presentation layer functions
- Layer 2 e layer 3
- Fig 19
- Secure socket layer and transport layer security
- Brown earth soil profile
- Soil profile
- Regolith in soil profile
- Podzol soil profile
- Soil profile
- Clay soil profile
- Gley soil profile diagram
- Latosol soil
- Latosol soil profile
- Higher geography biosphere
- A horizon
- What is soil made of?
- Top layer soil
- Deepest layer of soil
- Mortimer wheelar used scientific and soil layer method
- Layer of soil
- 3 horizon framework
- Diagnostic subsurface horizons
- Topmost mineral horizon
- What are the master horizons?
- Pennine horizons digital archive
- Ucsf day care
- Guardian consonant
- Lean horizons consulting
- Imperial horizons
- Limitless horizons ixil
- Diagnostic horizons