chapter five: soils

Question 1

percentages of optimal soil conditions

Answer 1

50 % solid:
-45% mineral matter from rocks
-5% organic matter
50 % pore space
-25% H2O
-25% air

Question 2

there are ___ soil orders

Answer 2

12

Question 3

layers of the soil that are part of the biosphere; interact with living things

Answer 3

fertile zone

Question 4

which three horizons are contained in the fertile zone

Answer 4

O
A
E

Question 5

soil horizon that contains humus and organic matter

Answer 5

O horizon

Question 6

the O horizon is where soil bacteria and fungi break down ___

Answer 6

organic matter

Question 7

organic matter that is partially broken down

Answer 7

humus

Question 8

a layer of topsoil

Answer 8

A horizon

Question 9

eluviation layer, where leaching occurs, the bottom of the topsoil

Answer 9

E horizon

Question 10

layers of the soil that are not part of the biosphere do not interact with living things

Answer 10

infertile zone

Question 11

4 soil horizons in the infertile zone

Answer 11

I
B
C
R

Question 12

illuvial layer; zone of accumulation for minerals/elements, top of subsoil

Answer 12

I horizon

Question 13

subsoil; mixture of sand, silt, and clay; impenetrable to most things

Answer 13

B horizon

Question 14

unconsolidated parent material

Answer 14

C horizon

Question 15

regolith layer; solid parent material (bedrock); where minerals come from

Answer 15

R horizon

Question 16

the percent sand, silt, and clay in a given soil

Answer 16

soil texture

Question 17

sand, silt, and clay are ___ identical; they are defined by ___

Answer 17

chemically
diameter of particle

Question 18

ideal soil with balanced parts of sand, silt, and clay (one third of each)

Answer 18

loam soil

Question 19

clay particles are ____ in diameter

Answer 19

< 0.002mm

Question 20

what is the shape of clay particles

Answer 20

flat, not globular

Question 21

individual clay particles are called ___

Answer 21

micells

Question 22

clay particles (micells) have a ___ charge

Answer 22

negative

Question 23

micells will permanently suspend in water, so they are known as ___

Answer 23

colloids

Question 24

shape of silt particles

Answer 24

globular

Question 25

silt particles are ___ in diameter

Answer 25

0.002-0.05mm

Question 26

sand particles are ___ in diameter

Answer 26

0.05-2.0mm

Question 27

sand types in order from smallest to largest particles

Answer 27

very fine sand fine sand medium sand coarse sand very coarse sand

Question 28

can you change soil texture

Answer 28

no

Question 29

the appearance of soil when it clumps together

Answer 29

soil structure

Question 30

can you change soil structure

Answer 30

yes, by mixing

Question 31

5 soil forming factors

Answer 31

1. parent material 2. climate 3. topography 4. living organisms and organic composition 5. time

Question 32

rock that the mineral matter in the soil is made from

Answer 32

parent material/regoliths

Question 33

___ and ___ are the most common regoliths

Answer 33

granite and basalt

Question 34

parent material accumulates through weathering of these 3 types of rock from these sources

Answer 34

1. igneous rock from volcanic activity 2. sedimentary rock from depositing by glaciers, water, or wind 3. metamorphic rock from changes in igneous or sedimentary rocks from extreme pressure, heat, or both

Question 35

___ and ___ are the two most important factors for climate

Answer 35

temperature and rainfall

Question 36

lay of the land

Answer 36

topography

Question 37

in steep land, soil may ___ or ___ because of wind, water, and ice

Answer 37

wash away or erode

Question 38

in flat land, ___ and ___ may appear when it rains

Answer 38

pools and ponds

Question 39

what is the topography in East Tennessee called that contains mostly foothills

Answer 39

rome formation

Question 40

an ideal topography for soil formation is one that permits ___ without ___

Answer 40

drainage erosion

Question 41

the most important soil forming factor

Answer 41

time

Question 42

it takes ___ years for one inch of topsoil to develop

Answer 42

1000

Question 43

3 types of water found in soil

Answer 43

1. hydroscopic water 2. gravitational water 3. capillary water

Question 44

what is hydroscopic water

Answer 44

water chemically and permanently bound to the soil

Question 45

hydroscopic water is ____, no matter how dry the soil seems

Answer 45

always present

Question 46

is hydroscopic water available to the life in/on the soil

Answer 46

no

Question 47

can hydroscopic water be removed under natural conditions

Answer 47

no

Question 48

how is hydroscopic water removed in a lab

Answer 48

baked at 400 degrees for days

Question 49

what is gravitational water

Answer 49

water that passes through the soil system into the water table by gravity

Question 50

underground water that can be shallow or deep

Answer 50

water table

Question 51

gravitational water is ___ in the soil after rainfall

Answer 51

temporarily

Question 52

gravitational water is ___ available to life in/on the soil

Answer 52

temporarily

Question 53

what is capillary water

Answer 53

water help against gravity in pores of the soil

Question 54

capillary is the ____ to life in and on the soil

Answer 54

most available

Question 55

the amount of capillary water and area can potentially hold

Answer 55

field capacity

Question 56

___ is the most important factor in determining field capacity

Answer 56

soil density

Question 57

is soils heavy in clay reach a field capacity of ___, plants reach a permanent wilting point

Answer 57

less than 15%

Question 58

if sandy soils reach a field capacity of ___, plants reach a permanent wilting point

Answer 58

less that 4%

Question 59

the most important biological parameter of all

Answer 59

pH

Question 60

____ in soil causes certain minerals (like copper, iron, and manganese) to become less available to plants

Answer 60

alkalinity

Question 61

acidity in soil inhibits the growth of ____

Answer 61

nitrogen-fixing bacteria

Question 62

adding ___ to soil makes alkaline soils more acidic

Answer 62

sulfur

Question 63

"black earth" in the midwest

Answer 63

mollisols

Question 64

black pigments in soil come from ___

Answer 64

organic matter

Question 65

red pigments in soil come from ___

Answer 65

iron and aluminum oxides

Question 66

white pigments in soil come from ___

Answer 66

silicates and salt

Question 67

found in the midwest where deserts meet grasslands

Answer 67

cryptobiotic soils

Question 68

cryptobiotic soils have a ___ on the top of the ground that is ___ and will ___ underneath the foot

Answer 68

crust cake-like crunch

Question 69

cryptobiotic soils are ___ in color

Answer 69

light (mosaic)

Question 70

cryptobiotic soils are rich in ___ and ___ that are only found in this soil

Answer 70

bacteria and fungi

Question 71

cryptobiotic soils are the ___ soils on the planet

Answer 71

rarest

Question 72

cryptobiotic soils contain rare compounds that could be ___

Answer 72

medicinal