Exam 3

Question 1

Definition of Soil

Answer 1

Layer(s) of generally loose mineral and organic material that are affected by chemical, physical, and biological processes at or near the planetary surface and usually holds liquids, gasses, and biota and support plants

Question 2

Spheres that interact the pedosphere (soils)

Answer 2

-Hydrosphere
-Lithisphere
-Biosphere
-Atmosphere

Question 3

4 main components of soil

Answer 3

-Minerals
-Air
-Water
-Organic matter

Question 4

Model of Soil Formation

Answer 4

S=F(cl,o,r,p..)
T

Question 5

Regolith

Answer 5

Area of soil right above parent material

Question 6

Chemical weathering is more common in what environment

Answer 6

Hot and wet environment

Question 7

6 roles of soil

Answer 7

-Habitat
-Construction material, foundation
-Plant growth
-Modify atmosphere
-Control water
-Recycle waste

Question 8

Three size classes

Answer 8

-Sand (largest)
-Silt
-Clay

Question 9

Area called the “living skin” of earth
Air, water, rocks, and life interact

Answer 9

Critical zone

Question 10

Master Horizons and Features

Answer 10

-O:Organic Matter
-A: Organic Matter and Minerals
-E: Eluviation, loss of material
-B: Alteration to parent materal, subsoil
-C: Partial parent material, little alteration, unconsolidated
-R: Actual parent rock, consolidated

Question 11

Transition Horizons

Answer 11

Horizons that have characterisitics from two different horizons
Denotes the use of two letters AB, BA, etc

Question 12

Three types of Organic material

Answer 12

-Litter: Fresh material
-Fermented: Beging decomp, still distingushable
-Humic: Origins not distingushible

Question 13

Four Major Processes of Soil Formation

Answer 13

-Translocation:Material moves up or down the horizon or in and out
-Transformations: decomp and rock weathering
-Additions:Dust
-Losses:Water

Question 14

Soil Profile vs. Horizon

Answer 14

Profile is a verticle cut into the Earth and has many horizons
Horizon is just one section

Question 15

Taxonomic soil category that covers the most area, but has the least amount of info

Answer 15

Order

Question 16

Taxinomic Categories from least information to most

Answer 16

1.Order
2.Suborder
3.Great Group
4.Subgroup
5.Family
6.Series

Question 17

Subgroup

Answer 17

Divides the Great Group into categories based on atypic characteritics
Its the same soil just a little different

Question 18

Typic definition

Answer 18

Contains the central characteritic
Would fall between two atypic subgroups
Ex. Between aridic and aquertic would be typic

Question 19

Entisols

Answer 19

-Recent
-Little to no soil profile development
-Alluvial to sand barrens

Question 20

Inceptisols

Answer 20

-Young w/ rapid development
-Pacific Northwest and Northeast

Question 21

Andisols

Answer 21

-Volcanic ash layers
-Near volcano or downwind
-High natural fertility

Question 22

Gelisols

Answer 22

-Young soil, minimal profile development
-Permafrost
-Not good for ag or development
-Store a lot of carbon

Question 23

Histosols

Answer 23

-20% organic matter
-Black to Dark Brown
-Developed in wet environments (like wetlands)

Question 24

Aridisols

Answer 24

-Arid, dry
-Dry year round
-Most common soil in the west

Question 25

Vertisols

Answer 25

-High clay content -Creates cracking on surface layer when dry

Question 26

Mollisols

Answer 26

-Most productive w/o fertillizers -High organic content

Question 27

Alfisols

Answer 27

- Aluminum and Iron -Midwest -Highly productive

Question 28

Ultisols

Answer 28

-Subtropical to tropical -Red to Yellow -Prone to leeching -Southeastern US

Question 29

Spodosols

Answer 29

-Wood Ash -Acidic -Pine tree forests, creates the high acid content

Question 30

Oxisols

Answer 30

-Highly weathered -High clay content -Tropics

Question 31

Effective Precipitation

Answer 31

Precipitation that reaches the regolith

Question 32

Why is effective precipitation important in soils

Answer 32

The movement of precipitation can bring soluable materials down or break up parent rock The lack of precipitation may keep certain materials in place

Question 33

Residual Material

Answer 33

Material that is formed directly from the parent material (bedrock)

Question 34

Rock Fragments that are transported down Course and stony

Answer 34

Colluvial debris/material

Question 35

Alluvial Deposits

Answer 35

-Lowest area comapred to Rsidual and Colluvial -Deposited Sediment

Question 36

Hydrolosis

Answer 36

-Water splits into H and O2 -H replaces a cation on the mineral

Question 37

Biogeochemical weathering

Answer 37

The conversion of primary minerals to secondary minerals and releasing soluable plant nutrients

Question 38

Two Types of Clays

Answer 38

1:1 (nonexpansive) 2:1 (expansive)

Question 39

1:1 nonexpansive clays

Answer 39

Has just one layer of the octahedral and tetrahedral structures

Question 40

2:1 expansive clays

Answer 40

Has one layer of the octahedral structure and two of the tetrahedral This allows for water molecules to go between the two interlocking tetrahedral structures* | *Think magnet

Question 41

Loam

Answer 41

Mixture of sand, silt, and clay Display properties evenly Not in equal amounts

Question 42

Hue (Munsell Color Book)

Answer 42

Your basic color(s) Ex: 5YR

Question 43

Value

Answer 43

Lightness/darkness of soil Value is arranged vertically

Question 44

Chroma

Answer 44

Color intensity Left to right

Question 45

Hue, Value, Chroma of 5YR 7/6

Answer 45

Hue: 5YR Value: 7 Chroma: 6

Question 46

Permability

Answer 46

How well the soil holds water | Sand has a low permability

Question 47

Infiltaration

Answer 47

Water entering the pore spaces

Question 48

Sand's infliration rate

Answer 48

High infiltration due to large pore spaces

Question 49

Clay holds a lot of water but some may not be accesable why?

Answer 49

Majority is microscopic water, plants are not able to pick this up

Question 50

Dissolution

Answer 50

Water comes together and weathers down the mineral

Question 51

Acids come together and wears down the minerals

Answer 51

Complexation

Question 52

Bulk Density

Answer 52

g/cm^3 of soil particles and pore spaces

Question 53

Porosity corrilates to which soil characteristic

Answer 53

Pore space

Question 54

Pore spaces correlation to bulk density

Answer 54

Less pore space = more bulk density