Entisol

very young soil, no B horizon

slow soil creation and new soils

dry, cold, and new deposits

highly veriable in feritility based on nutreints

        A(thin)

C

R

Inceptisol

young (more developed then Entisol)

weakly developed B

feritily variable based on PM

A

BW

C

Andisol

significant influence from volcanic ash

young soil - Bw

volcanic glass -> Si, Fe, Al -> quick release minerals

super small (unmeasurable) crystal structure

high H₂O holding capacities

low fertility, too much Si

      A (thin)

Bw

2C

Gelisol

frozen most of the year

hard to build on - melt and collapse

f = frozen, fertility limited by Climate

O

A

Cf

Histolols

wet -> high OM

Bogs, fens, etc

wetland ag, or drained

shrinks when dry, low strength

mine for fuel and soil amendment

Oe₁

Oe₂

Aridisols

Dry, Hot solid

plant growth restricted -> thin A

k because too little H₂O to leach

naturally low fertility, can be changed with H₂O

salt content potential problem

A(thin)

Bk

Bkm

R

Vertisol

churning/mixing - shink swell clays

>30% clay (shink swell) -> smectites

Ca rich PM = limestone, basalt, etc

deep cracks -> makes peds (blocks)

subhumid to semiarid, needs wet and dry seasons

ss = slikensides, polished peds

good ferility, 24 hour soils

              A(grasslands)

Bss

Alfisols

Forested, transfer of clay, illuvial -> Bt

High base cation - Ca, Mg, K

high fertility, stable = best all around soil

A

              Bt₁ (Deep Bt)

Bt₂

Ultisols

high weathering -> semi tropical -> south east US

low base Cations, leached -> acidic soil

A

E

Bt₁

Bt₂

Mollisols

most productive ag soils, prairie

Deep A, high in Ca = High fertility

Good physical properties

             A₁ (Deep A)

A₂

Bt

C

Spodosols

leached E -> lot of water

course/sandy/PM

acidic forest - coniferous -> low base cations

poor fertility

Oi (forested)

E

Bs or Bh or Bhs

Oxisols

Super weathered

red through out = piles of rust = minerals weathered away

low fertility, fast nutrient cycle of OM

clay not shrink/swell good structure

A

Bo₁

Bo₂

Bo₃