1) Ss121 Cal Poly Soil Science 121 Midterm #2

Front 1

Gelisol soil is noted by what feature?

Back 1

its permafrost

Front 2

What are the conditions of permafrost for it to be considered permafrost?

Back 2

permafrost is material that remains below 0*C for more than 2 consecutive years

Front 3

_________ or (frost churning) is where the above permafrost layer results in distinctive surface features

Back 3

Cryoturbation

Front 4

What is the only state in the United states that Permifrost is found?

Back 4

Alaska

Front 5

Histosols are what types of soil?

Back 5

organic soils

Front 6

_________ is formed from organic parent material in wet environments

Back 6

Histosols

Front 7

in what type of soil is New plant material produced faster than old plant material decomposes?

Back 7

Histosols

Front 8

What type of soil is Fertile, acidic, lightweight with high water-holding capacity?

Back 8

Histosols

Front 9

What soils have little or no horizon development?

Back 9

Entisols

Front 10

Under what conditions do Entisols form?

Back 10

-Recently deposited parent material
-Landscapes with active erosion or deposition of materials
-Climatic conditions not conducive to horizon formation
-Parent material too inert to develop soil horizons (quartz sands)
-Deep mixing of horizons by man

Front 11

_____% of entisols are found in deserts

Back 11

60%

Front 12

__________ are responsible for 16% of global ice-free land - most extensive

Back 12

Entisols

Front 13

What is the name of the sandy Entisol from the Mojave desert of California?

Back 13

Psamment

Front 14

What is the name of the Entisol formed in the Northern Casade mountains?

Back 14

Orthent

Front 15

What soils have weak horizon development?

Back 15

Inceptisols

Front 16

What soils are considered young?

Back 16

inceptisols

Front 17

What is the name of the inceptisol type that is found in the northern cascade mountains of california?

Back 17

Xerept

Front 18

What is the name of the soil order that arises from young volcanic soils?

Back 18

Andisols

Front 19

What are some of the soil properties of andic soil?

Back 19

-Low bulk density
-Potential for wind erosion
-Amorphous clays (allophane)
-High macroporosity with rapid drainage

Front 20

this soil order is the highly productive soil of hawaii with large amounts of humus and has high CEC

Back 20

Andisols

Front 21

What is the soil Order characterized by desert soils?

Back 21

Aridisols

Front 22

This soil order is characterized by having long dry periods and only short periods of wetness

Back 22

Aridisols

Front 23

This soil profile is characterized by the vegetation of Desert shrubs and bunch grasses.

Back 23

Aridisols

Front 24

________ soils int he imperial valley are highly productive

Back 24

Aridisols

Front 25

This type of aridisol formed in gravelly alluvium in the mojave Desert. It is characterized by having a cemented horizon

Back 25

Durid

Front 26

This is the soil of grasslands

Back 26

Mollisols

Front 27

What soil order is characterized by accumulation of Ca-rich organic matter from dense prairie grass roots, Thick mollic epipedon, and being highly fertile?

Back 27

Mollisols

Front 28

Mollisols consist of approximately ______% of the U.S.

Back 28

22%

Front 29

This soil order consists of the largest land area of the United States

Back 29

Mollisols

Front 30

This soil order is characterized by swelling and cracking clays

Back 30

Vertisols

Front 31

This soil is 'self-mixing’ soils containing >30% of high shrink-swell smectite clays

Back 31

Vertisols

Front 32

This type of soil has a deep A horizon with often no B horizon and a vegetative grassland

Back 32

Vertisols

Front 33

This soil order is identified by being a fertile soil with subsoil clay

Back 33

Alfisols

Front 34

Alfisols are the result of these types of vegitation _______ or _________

Back 34

deciduous forests or grasslands

Front 35

This soil order is characterized by having fertile soils with subsoil clay

Back 35

alfisols

Front 36

The indian state soil, and the san joaquin california state soil are in this soil order

Back 36

Alfisols

Front 37

This soil order is characterized by having humus under sand

Back 37

spodosols

Front 38

This is the highly acidic soil characterized by being the soil of coniferous forests

Back 38

spodosols

Front 39

This soil order is characterized by having highly leached soils with subsoil clay

Back 39

Ultisols

Front 40

this soil is highly leached of basic cations and often has an E horizon

Back 40

Ultisols

Front 41

This soil order is characterized by having highly oxidized soils

Back 41

Oxisols

Front 42

This is the soil type of tropical rain forests

Back 42

Oxisols

Front 43

what are the 3 soil physical properties?

Back 43

Texture, structure, and bulk density

Front 44

what is soil texture?

Back 44

the sizes of particles in a osil

Front 45

what is the size range of sand?

Back 45

2.0- 0.05 mm

Front 46

What is the size range of silt

Back 46

0.05 - 0.002 mm

Front 47

What is the size range of clay

Back 47

<0.002

Front 48

_____________ is the arrangement of soil particles into groupings called aggregates (peds) that are separated by planes of weakness (macropores)

Back 48

Soil structure

Front 49

This is a network of sticky roots and fungal hyphae

Back 49

macroaggregates

Front 50

this is organic glues produced by bacteria and fungi, decomposing organic matter, and earthworm casts

Back 50

Microaggregates

Front 51

What are the poitive and negative effects of tillage on soil?

Back 51

Positive effects: break up large clods, incorporate OM, increase total porosity.

Negative effects (wet soil): increases rate of OM decomposition, crush stable aggregates, decrease macroporosity

Front 52

Soil pore space makes up ____% to _____% by volume

Back 52

25% to 60%

Front 53

These pores are formed by roots, earthworms and insects, and are important in clay soils

Back 53

biopores

Front 54

What is the equation for soil bulk density?

Back 54

Soil mass (g)/ soil volume (cm^3)

Front 55

Soil particle density is different then soil bulk density because...

Back 55

soil particle density doesn't include soil pore spaces.

Front 56

What is the average soil particle density?

Back 56

2.60 g/cm^3

Front 57

what has more pore space sandy soils or clay soils?

Back 57

clay soils have more pore space

Front 58

what has a greater bulk density sandy soils or clay soils?

Back 58

sandy soils have a greater bulk density

Front 59

Soil strength is the measure of what?

Back 59

the measure of how difficult it is for roots to push particles aside.

Front 60

How does agriculture management effect soil bulk density?

Back 60

it increases soil bulk density

Front 61

What are the three factors of the munsell color system?

Back 61

-Hue (redness or yellowness)
-Value (lightness/darkness; 0=black)
-Chroma (intensity/brightness; 0=neutral gray)

Front 62

What aspects in the soil does soil temperature effect?

Back 62

affects chemical, physical, and biological processes occurring in the soil

Front 63

What is the optimum temperature for microbial processes?

Back 63

30* C

Front 64

_________ is when alternate freezing and thawing of soil water forces objects upward in the soil, especially when soil is wet

Back 64

Frost Heaving

Front 65

in regards to soil strength what are cohesive soils?

Back 65

soils with a clay content >15%

Front 66

in regards to soil strength what are noncohesive soils?

Back 66

sandy soils

Front 67

What are some of the facts regarding Expansive soils?

Back 67

They contain shrink-swell clays (smectites), they occur in 20% of land area in US, they cause huge amounts of damage

Front 68

what type of bond links water molecules together?

Back 68

Hydrogen bonds

Front 69

This is the sticking of molecules to the same molecules

Back 69

cohesion

Front 70

this is the sticking of molecules to other types of molecules

Back 70

adhesion

Front 71

Total soil water potential is a combination of the the effects of what three potentials?

Back 71

matric potential, gravitation potential, osmotic potential