1. Gelisols

2. Histosols

3. Mollisols

4. Aridisols

5. Alfisols

6. Oxisols

7. Ultisols

8. Andisols

9.Inceptisols

10. Vertisols

11. Entisols

12. Spodosols

-Soils with permafrost layer

-Form in tundra areas

-Cryoturbation above permafrost layer results in distinct surface features

-In US, only in Alaska

-Soils with a lot of OM, CO₂ production

Organic Soils

-Formed from organic PM in wet environments

-New plant material produced faster than old plant material decomposes

-Fertile, acidic, lightweight with high H2O-holding capacity

-Reflood Florida swamp lands

Soils w/ little or no horizon development

-From from recent depost PM (recent alluvium)

-Lands with active erosion or deposition of materials

-Climatic conditions not condusive (DRY)

-PM too inert (not enough clay for Bt horizon) to develop soil horizons.

-Mix of horizons by man

-60% are in deserts

-ochric epipedon (Big Zero)

-Productivity depends on nature of PM

-Approx. 16% of global ice-free land - most extensive

-Thin A horizon over C horizon (Desert of CA)

-Form sandy and gravel old alluvium in cool, arid climate (Northern Cascade mountains)

Soils with weak horizon development

-little or no illuviation of clay/lime

-ochric epipedon

-cambic (Bw) horizon (the wannabe)

-Productive: variable as entisols

-In US: Appalacian Plateou region

           -Northern Cascade mtns.

Young volcanic soils (from volcanic ejecta)

-5,000 - 10,000 years old

-Not highly weathered

-Andic soil properties:

   -low bulk density: a lot of pore space

   -potential for wind erosion (very light)

   -high macroporosity w/ rapid drainage

-Melanic (A horizon that is black)

-Highly productive soils in Hawaii

-large amounts of humus (keeps structural units together)

-fertile (high CEC)

-easily worked

-In US: Alaska, some in CA and northern/western

Desert soils (older, more developed), and stable

-long, dry periods, short periods of wetness

   -reduced cation leaching

   -slow mineral weathering

   -accumulation of soluble salts

Aridisols

Profile

-ochric

-lime, salt, gypsum layers - control salts in root zone (need to be leached)

-Carbonates (Ca) throughout profile

-In US: Imperial valley, Nevada, Utah, AZ, MX

-AZ=aridisol "Casa Grande"

-Mojave desert= gravelly alluvium

Soils of grasslands

-Accumulation of Ca-rich OM from dense prarie grass roots

-Thick mollic epipedon (deep, lots of OM >2%) = thick A

-Humid to semi-arid regions

-Highly fertile (granular, loose structure)

-Easily managed

-Argillic, calcic epipedons

-Approx. 22% in US (largest area)

Swelling and cracking clays

-self-mixing contains >30% of high shrink-swell smectite clays.

-Develop from Ca and Mg-rich PMs (limestone, basalt) in sub-humid to semi-arid

-Deep A, no B horizon

-Fertile, difficult to manage (super sticky)

-Vegetation = grassland

-Gilgai and smectite

-In US: some in CA, most in Texas

-It inverts itself, parent material comes to the top

Fertile soils with subsoil clay

-Old soils develop under native diciduous forest (humid) or grassland (semi-arid) vegetation

-Usually thin ochric horizon, contains argillic subsurface horizon

-Fertile and productive

-water adequate source for growth season

-erodible

-moderately acidic (b/c old): carbonic acid, leaching of basic cations

Alfisols state soil

-Indiana

-Indiana state soil: Miami

-deep, well drained (moderately) - enough clay

-formed in CaCO₃ (calcareous) loamy till, slow acidification of soil

-slopes 0-60%

-Native vegetation: hardwood forest

San Joaquin

-moderately deep, moderately well-drained soils

-formed in alluvium from mixed but mostly granitic rock, low terrace

-Bqm (cemented durapan)

Ap

Bt

Bqm (cemented silica)

soils with humus under sand

-highly weathered soils developed in sandy, acidic PM's under high rainfall (leached) = E horizon

-vegetation: coniferous (acidic) littler

-contain spodic horizon, subsurfac accumulation of humus Al and Fe.

-NOT fertile

East coast (a lot in Florida - sand PM), in northwest, too

-In Mendocino, very nique b/c old, leached of nutrients, poorly drained b/c iron-cemented hardpan

-Pygmy forest:

   -low fertility and wetness

   -restrict growth = dwarf condition

highly leached, old soils, subsoil clay

-form on old, stable land surfaces

-leached of basic cations (acidic)

-Umbric or ochric A horizon

-Often E horizon

-Thick, acidic argillic Bt horizon

-Not naturally fertile, but can be well managed for Agriculture.

-"Red hills of Georgia"

highly weathered, oxidised soils

-Form on old land forms in humid, tropical climates

-vegetation: tropical rainforests

-Al and Fe oxides and kaolinitic clays

-low natural fertility, leached out, BUT easy to work (to get non-sticky clays)

-ochric or umbric A horizon

-In Hawaii, Puerto Rico (Bayamon)

-well drained, on coastal plains

-form in highly weathered clayey marine sediments

-low to medium fertility, strong acidity

-sugarcane, pineapples

-Some in Northern CA

-hardened laterite (developed about 60 mya when CA climate was tropical.)

-Was buried, later exhumed by natural processes

Sand

-size

-Texture

-made of

-size of pores

-surface area

-structure

-2.0-0.05 mm dia

-gritty, visible to naked eye

-primarily quartz - no nutrients

-Macropores= fast drainage and free air exchanges

-Less surface area= LOW water holding capacity

-non-cohesive single grained (won't stick together)