1) Soil Science Ss 121 Dr. Will Cal Poly Final

Front 1

__________ Consumes carbon for sustenance

Back 1

Heterotrophs

Front 2

__________ produces their own food (usually from the sun)

Back 2

autotrophs

Front 3

Forested soil, which is acidic, has a very high concentration in this type of microfauna

Back 3

fungi

Front 4

Grassland soil is high in these two types of organisms

Back 4

animal and microflora

Front 5

cultivated soils have high or low biomass?

Back 5

low biomass in the soil

Front 6

This is the most important macrofauna in soils

Back 6

earthworms

Front 7

Earthworms can be found in the top of the soil at a depth of __________.

Back 7

15-35 cm

Front 8

earthworms ingest soil and excrete ________.

Back 8

casts

Front 9

What is the Zone of soil significantly influenced by roots in terms of pH and nutrient levels?

Back 9

Rhizosphere

Front 10

These organisms are like small fungi like organisms that produce their own antibiotics and give soil its earthy smell

Back 10

actinomycetes

Front 11

In a symbiotic relationship between a microorganism and a plant _________ from the air is converted into ________ then into_________ where it is available for the plants

Back 11

atmospheric dinitrogen N2, ammonia (NH3), ammonium (NH4)

Front 12

In a symbiotic relationship with plants, microorganisms get this in return from the plant.

Back 12

sugars

Front 13

This is a soil organism that eats living organic material

Back 13

pathogenic organism

Front 14

this is a soil organism that eats dead organic material

Back 14

saprophytes

Front 15

This is the most important macrofauna in soils

Back 15

earthworms

Front 16

Earthworms can be found in the top of the soil at a depth of __________.

Back 16

15-35 cm

Front 17

earthworms ingest soil and excrete ________.

Back 17

casts

Front 18

What is the Zone of soil significantly influenced by roots in terms of pH and nutrient levels?

Back 18

Rhizosphere

Front 19

In a symbiotic relationship with plants, microorganisms get this in return from the plant.

Back 19

sugars

Front 20

The fallowing features are that of what soil organism?
-Aerobic heterotrophs
-May have visible structures fruiting (mushrooms)
-Organic matter decomposition - especially materials too complex for bacteria

Back 20

fungi

Front 21

These organisms can eat living or dead organic material

Back 21

facultative pathogens

Front 22

These organisms have long branching chains of cells, called hyphae, twisted together to form the mycelia

Back 22

Filamentous fungi

Front 23

fungi reproduce by ________

Back 23

spores

Front 24

These fungi are microscopic to semi-microscopic and are important in soil OM breakdown

Back 24

molds

Front 25

These fungi are important in the breakdown of woody tissue and have mycorrhizae

Back 25

mushroom producing fungi

Front 26

This is a Mutually beneficial (symbiotic) relationship between fungi and plant roots of most plants

Back 26

Mycorrhizae

Front 27

This type of micorrhize is present in trees and shrubs and its Hyphae extend out into the soil and between the plant cells but do not penetrate the cells

Back 27

Ectomycorrhhizae

Front 28

This type of micorrhizae is Formed on all types of plants except: crucifers (e.g., cabbage, mustard), sugar beet/spinach family. Also its Hyphae penetrate between cells and into cells where they form arbuscules (site of mineral nutrient and sugar transfer)

Back 28

Arbuscular mycorrhizae

Front 29

This type of mycorrhizae extends its hyphae in the soil and in between plant cells and is the most common type of mycorrhizae. usually found in grasses

Back 29

Endomycorrhizae

Front 30

This is a fungal respiratory illness that is common in the san juaquin valley

Back 30

Valley Fever

Front 31

These are very small fragments of clay and humus that is only visible with an electron microscope

Back 31

soil colloids

Front 32

________ are crystalline with planes of oxygen atoms that are held together by ionic bonding with silicon and aluminum atoms in between

Back 32

soil clays

Front 33

What are the two types of clay structures?

Back 33

-SiO4+ surrounded by 4 Oxygen atoms
-AL(3+) surrounded by 6 oxygen atoms

Front 34

________ is clay that has atoms that are not regularly arranged

Back 34

amorphous clays

Front 35

______ is where 2 tetrahedral sheets sandwiching one octahedral sheet

Back 35

2:1 clay

Front 36

_______ is where 1 tetrahedral sheets per octahedral sheet

Back 36

1:1 clay

Front 37

is clay positively or negatively charged?

Back 37

negatively charged

Front 38

_________ causes soil clay particles to be negatively charged

Back 38

excess negatively charged oxygen atoms

Front 39

-2:1 clay
-high swelling, sticky clays
-Most common in soils with little or no leaching - soils of arid regions, poorly drained soils

Back 39

Smectites

Front 40

-2:1 clay
-swells only slightly because layers are held together by K(+) ions
-Found in soils that are not extensively weathered
-Developed from parent materials containing micaceaou primary minerals (K, Mg, Fe)
-Moderate net negative charge due to isomorphous substitution

Back 40

Hydrous mica

Front 41

2:1
-Weathered illites in which the K(+) ions between the molecular sheets are replaced by Mg(2+) or Fe(2+)
-Moderate swelling limited because layers are held together weakly
-High net negative charge due to isomorphous substitution and high exposed surface area

Back 41

Vermiculite

Front 42

-1:1 clay
-No isomorphous substitution (low net negative charge)
-Each layer has one plane of O(2-) replaced by OH(-)
-Results in strong H bonds to the O plane of adjacent layer
-no swelling
-Found in acidic, humid, well-drained soils
-Silica and basic cations leached from profile leaving high Al needed for kaolinite formation

Back 42

Kaolinite

Front 43

-Mixtures of Al and Fe oxides and hydroxides [Al(OH)3, Fe2O3, Fe(OH)3] remaining after most of the silica and alumina of primary minerals are dissolved and leached out
-Formed under extensive leaching and long-time intensive mineral weathering
-Dominant clay only in soils formed in humid, hot, well-drained tropical areas
-Do not swell, are not sticky, do absorb water
-No to very little net negative charge

Back 43

Sesquioxide clays

Front 44

-Important in surface horizons
-Higher net negative charge on a dry weight basis than clay
-Net positive charge at low pH

Back 44

Humus

Front 45

The charge on humus is related to pH because

Back 45

H+ ions in acidic soils bond to the humus

Front 46

__________ is the total amount of negative sites on a soil particle

Back 46

Cation Exchange Capacity (CEC)

Front 47

how is CEC mesured?

Back 47

centimoles (+) of cations per kg soil [cmol (+)/kg

Front 48

Warm humid areas tend to get more acidic or basic?

Back 48

acidic

Front 49

_________ toxicity is the most common and severe problem for plants and microorganisms in soil with pH 5 and below

Back 49

Aluminum toxicity

Front 50

pH _______ to _______ is ideal for plant growth

Back 50

5.5 to 7

Front 51

you can raise a soil's pH by _____ the soil, _________ charged particles consume the H ions

Back 51

Liming, negatively

Front 52

if a soil has high buffer capacity in a soil more/less (chose one) lime is needed to increase the pH

Back 52

more lime is needed to increase pH

Front 53

Under natural conditions, when the precipitation-to Evapotranspiration ratio that is 0.75 or less, _________ will accumulate in the soil

Back 53

salts

Front 54

__________ formation in semiarid areas where salt-rich substrata are underlain by impermeable layers are put into agriculture

Back 54

saline seep

Front 55

What are the methods used to measure salt in soils?

Back 55

EC, ESP, SAR

Front 56

_______ is where salt effects the plant by decreases the water potential of soil solution to the point where the plants cannot extract water

Back 56

Osmotic effect

Front 57

What are the three ways to reclaim any soils affected by salts?

Back 57

-Establish internal drainage if possible
-Replace excess exchangeable Na if it is a problem
-Leach out most of the soluble salts in the root zone with good quality irrigation water

Front 58

This area in california has a severe salt problem

Back 58

Imperial Valley

Front 59

What law states: Plant growth can be no greater than that level allowed by the growth factor present in the lowest amount?

Back 59

Liebig's law of the minimum

Front 60

What are the soil factors that reduce plant nutrient uptake?

Back 60

soil compaction, cold temperatures, low soil moisture, high microbial activity, too much water, poor aeration, extremes in root temperature

Front 61

_______ is a major component of amino acids and is the most managed nutrient

Back 61

nitrogen

Front 62

These are the symptoms of ________.
Chlorosis - pale yellowish-green
-Spindly stems
-mobile element

Back 62

Nitrogen Deficiency

Front 63

________ is where N in organic compounds converted to NH4+ and released into the soil

Back 63

Mineralization

Front 64

__________ is the Conversion of NH4+ ions (from organic matter or fertilizers) to organic forms in microbial and plant cells

Back 64

Immobilization

Front 65

__________ is the Production of ammonia gas from breakdown of organic matter and chemical fertilizers (anhydrous ammonia)

Back 65

volatilization

Front 66

______ is the Bacterial oxidation of NH4(+) ions to nitrites, then nitrates

Back 66

Nitrification

Front 67

_________ is when Lakes, estuaries, or slow-moving streams receive excess nutrients and aquatic organisms die

Back 67

Eutrophication

Front 68

_______ is where NO3 converts back to N2

Back 68

Denitrification

Front 69

__________ is the second most essential plant nutrient and is used in ATP, DNA, RNA, and phospholipids (cellular membranes)

Back 69

Phosphorus

Front 70

The fallowing are symptoms of _________.


-Stunted growth
-Spindly stems
-Dark, bluish-green foliage
-Sparse flowering and poor seed quality

Back 70

Phosphorus deficiency

Front 71

Third most important plant nutrient and is absorbed in its elemental form by the plant, and helps it adapt to environmental stresses

Back 71

Potassium

Front 72

The fallowing are symptoms of what?

-tips and edges of older leaves yellow and die
-In legumes - small, white necrotic spots near leaf edges

Back 72

Potassium Deficiency

Front 73

________ is needed for Part of the structural of some amino acids and vitamins, and needed to make chloroplasts

Back 73

Sulfer

Front 74

sulfer is present in acidic or basic soils?

Back 74

acidic (likes soils with high anion exchange capacity)

Front 75

___________ is Critical to root growth, and is Most plentiful cation on exchange complex in neutral and slightly acid soils

Back 75

calcium

Front 76

__________ is Part of the chlorophyll molecule, used in making proteins

Back 76

Magnesium

Front 77

Metal micronutrients prefer slightly acidic or alkaline soils?

Back 77

acidic (they have a positive charge and like high CEC soils)

Front 78

Metal micronutrients form organo-metallic complexes called ___________.

Back 78

chelates

Front 79

what are the three anion nutrients?

Back 79

Cl, B, Mo

Front 80

________ is the most commonly defficient micronutrient

Back 80

Boron

Front 81

_________ is the Reduction in capacity of the soil to support life, through the damage to physical, chemical or biological properties, contributing to an unsustainable ecological system

Back 81

land degradation

Front 82

What are the three types of land degradation?

Back 82

Physical, chemical, biological

Front 83

________ is Land degradation in arid, semi-arid and sub-humid areas resulting from complex interactions among physical, biological, political, social, cultural and economic factors (UNCCD)

Back 83

Desertification

Front 84

An estimated 24 billion tons of fertile soil disappear annually due to _________

Back 84

soil erosion by water and wind

Front 85

What are the three steps for water to erode soil?

Back 85

Detachment, Transport, Deposition

Front 86

This erosion by water is relatively uniform erosion from the entire soil surface. Cause of most soil loss

Back 86

Sheet erosion

Front 87

This erosion by water is initiated when the water concentrates in small channels as it runs off the soil.

Back 87

Rill erosion

Front 88

This erosion by water is when water creates deep channels that can not be erased by cultivation.

Back 88

Gully erosion

Front 89

How do you reduce water erosion?

Back 89

use a cover crop or have a no till zone

Front 90

Soil wind erosion consists of _________ and __________.

Back 90

Detachment and Transportation

Front 91

What is the speed required to generate wind erosion on soil?

Back 91

15 mph wind

Front 92

What can be done to prevent wind erosion?

Back 92

Moisten soil when high winds predicted
-Maintain vegetative cover
-Till at moisture content appropriate to make clods when winds expected
-Till at right angles to prevailing winds
-Barriers - shelterbelts