12 Soil Types

Question 1

Alfisols

Answer 1

Alf- Al & Fe, sol- soil
Formed under forests
In temperate, humid, & subhumid regions
Clay is present
Moderate amount of leaching
Means nutrients have moved down into lower soil horizons
Have at least 35% saturation ability

Question 2

Andisols

Answer 2

Ando- Black soil
Formed from Volcanic ash or other ejections
Have glass
Able to hold large amount of phosphorus, but unavailable to plants
Able to hold lots of water
The smallest amount of land made by these soils

Question 3

Aridsols

Answer 3

Aridus- dry
Found in arid regions
Dry most the year
Little leaching
Typically not used for agriculture, unless heavily irrigated
Contain CaCO3 (calcium carbonate)

Question 4

Entisols

Answer 4

Enti-?
Lack horizons
Can occur anywhere and form under any vegetation
Newer soils or at least more recently disturbed soils
Most numerous soils
Also a catch all for soils that don’t fit into other categories

Question 5

Gelisols

Answer 5

Gelare- to freeze
Extremely cold climates with permafrost within 2m of the surface
Organic matter at the top
Has a layer of permafrost underneath
Very sensitive to human activity because of the permafrost layers

Question 6

Histosols

Answer 6

Histos- Tissue (like animal and plant tissue)
Contain 20-30% organic matter
Called peats and muck
Limited human usefulness, subside when drained & low weight bearing ability
Form in wetlands with little drainage
HUGE ecological usefulness
Great for sequestering carbon in the ground

Question 7

Inceptisols

Answer 7

Inceptum- beginning
Little horizon development
Found in most places except arid regions
Many in mountainous regions where forestry and silviculture happen
Second most abundant type of soil

Question 8

Mollisols

Answer 8

Mollis- soft
Form in grasslands
Thick dark surface horizon
Some of the most important agricultural soils
Found in middle latitudes, prairies, great plains

Question 9

Oxisols

Answer 9

Oxide- weathered
Found mostly in intertropical areas
Has few weatherable minerals and is rich in Fe and Al oxides
Extremely low fertility
The oxides hold onto the phosphorus

Question 10

spodosols

Answer 10

Spodos- wood ash
Light colored E horizon with reddish/brown layer underneath
Called spodic horizon
Acidic soils with subsurface humus with Al and Fe
Found commonly in coniferous forests
Dry, cool areas
Infertile for crop growing (needs lime to neutralize the acidity)

Question 11

Ultisols

Answer 11

Ultimus- last
Strongly leached, acidic forest soils with low fertility
Supports productive forest though
Found commonly in SE US
Found in humid, temperate areas in older and stable areas
Much weathering means Ca, Mg, K have been leached from the soil
Lots of subsurface clay accumulation
Tend to be red or yellow in color

Question 12

Vertisols

Answer 12

Verto- turn
Clay rich soils that shrink and swell when water content changes
Large deep cracks during dry periods
Expands when water enters it
Prevents formation of horizons
Makes building and other human activities difficult

Question 13

Order of Soil Horizons

Answer 13

O
A
B
E
C
R

Question 14

O horizon

Answer 14

organic layer- dead, decaying, and living organic matter. Highest carbon content

Question 15

A Horizon

Answer 15

layer- top soil- partially broken down organic matter, very fine and well integrated. Nutrients easily accessible by roots and worms.

Question 16

E Horizon

Answer 16

Eluviated layer- leached minerals, where rainfall carries nutrients from higher layers.

Question 17

B Horizon

Answer 17

B layer- sub soil. Some, very little leached minerals. Where salts lie, heavier minerals like lead . get stuck down there. Larger rock from parent material

Question 18

C Horizon

Answer 18

C layer- partially weathered parent material

Question 19

R Horizon

Answer 19

R layer- Bedrock, original parent material