Deck 18: The Geography of Soils

Question 1

The basic sampling unit,in soil surveys representing all the characteristics and variability used for classification,is

A)soil profile.
B)pedon.
C)soil horizon.
D)polypedon.
E)regolith.

Answer 1

B

Question 2

Soils will develop at faster rates in which of the following environments?

A)hot and dry
B)cold and dry
C)warm and humid
D)cool and dry
E)cool and moist

Answer 2

C

Question 3

Which of the following best describes soil?

A)Soil is composed of solely mineral fragments less than 2 mm in size.
B)Soil lacks biological material,constituting only the inorganic portions of earthen materials.
C)Soil is an inorganic substance,yet vital to sustaining life,particularly plants.
D)Soil is a dynamic material composed of water,air,mineral fragments,and organic matter.
E)Soil is a closed system in terms of matter (water,rock,and sediments),but open in terms of energy (insolation).

Answer 3

D

Question 4

The horizon in which leached materials from other horizons is accumulated is the horizon.

A)A
B)O
C)E
D)B
E)C

Question 5

Which of the following best describes the composition of healthy soil?

A)Soil is primarily mineral matter (approximately 72%),but also consists of organic matter (10%),and water (18%).
B)Soil consists of approximately 45% organic matter,50% mineral matter,and 5% water and/or air.
C)Soil is composed of about 45% mineral matter,5% organic matter,and 50% pore space containing air and water.
D)Soil includes pebbles,gravel,cobbles,and a varying combination of sands,silts,and clays.
E)Soil contains three important ingredients,organic matter (50%),inorganic material (45%),and air (5%).

Question 6

Which of the following is not a physical property used to distinguish soils?

A)color
B)texture
C)porosity
D)moisture
E)temperature

Question 7

is the ability of soil to sustain plants.

A)Porosity
B)Texture
C)Soil fertility
D)Cation exchange
E)Structure

Question 8

The organic rich horizon found at the top of the soil profile is the horizon.

A)A
B)O
C)E
D)B
E)C

Question 9

A vertical cross section of soil extending from the surface to the deepest extent of plant root activity or to the regolith and bedrock is known as a

A)pedon.
B)soil profile.
C)soil horizon.
D)polypedon.
E)regolith.

Question 10

In regards to soil-formation,which of the following best describes the role of climate?

A)Because all soils are ancient,they show the climatic conditions of the period in which they formed.
B)Of the five principle soil-forming factors,climate is the least significant with little correlation between soil and climates worldwide.
C)Temperature and moisture determine the chemical reactions,organic activity,and water movement within soils.
D)Relative humidity and atmospheric pressure are the dormant climatic factors that influence soil development.
E)Soil forms at such a slow rate,while climate changes more rapidly,so the role of climate is minimal,yet not insignificant.

Question 11

Which of the following soil horizon designations is the correct sequence from the surface to the bedrock?

A)O,E,C,B,A
B)A,B,C,O,R
C)S,O,I,L
D)A,B,C,E,O,R
E)O,A,E,B,C,R

Question 12

The horizon identified as regolith is the horizon.

A)A
B)O
C)E
D)B
E)C

Question 13

Another term for soils,based on the Greek term thereof,is

A)pedosphere.
B)edaphosphere.
C)geosphere.
D)biosphere.
E)asthenosphere.

Question 14

The branch of soil science that deals with the origin,classification,distribution,and description of soils is known as

A)pedology.
B)edaphology.
C)geology.
D)geomorphology.
E)mineralogy.

Question 15

The horizon in which water moves fine particles downward in a process called eluviation is the horizon.

A)A
B)O
C)E
D)B
E)C

Question 16

Which of the following best describes the role of biological activity in soil development?

A)Since soil is primarily inorganic matter,the role that organisms play in soil formation and development is obvious only on the surface and top layer of soil.
B)While burrowing animals churn soil,the role of other organisms in soil formation and development is mostly muted.
C)The largest contribution organisms make to soil development is through fertilization via their waste products.
D)Given the amount of time it takes soil to form,the contribution organisms make to soil development is through decomposition,alone,adding needed organic matter to soils.
E)All organisms living in,on,and over the soil may influence the development and characteristics of soil.

Question 17

A vertical section of soil is generally organized into distinct horizontal layers called

A)soil profiles.
B)pedons.
C)soil horizons.
D)polypedons.
E)regolith.

Question 18

Where would one likely find the deepest soil development?

A)on steep slopes
B)level or nearly level grounds
C)moderately sloping,south facing hills
D)over the oldest geological formations in an area,regardless of slope
E)in biologically productive areas,regardless of slope or aspect

Question 19

The horizon that is commonly called topsoil is the horizon.

A)A
B)O
C)E
D)B
E)C

Question 20

Which of the following is not one of the five primary soil-forming factors?

A)topography
B)climate
C)human activity
D)biological activity
E)parent material

Question 21

Soil Texture Triangle A soil that is 20% sand,60% silt,and 20% clay is classified as

A)sandy clay.
B)sandy clay loam.
C)silt loam.
D)clay loam.
E)clay.

Question 22

Soil Texture Triangle A soil that is 40% sand,40% silt,and 20% clay is classified as

A)loam.
B)silty clay.
C)silt loam.
D)clay loam.
E)sandy clay.

Question 23

Carbon dioxide concentrations in soil are than (as)in the atmosphere because .

A)lower;transpiration
B)lower;plant photosynthesis
C)higher;ongoing respiration in the ground
D)higher;decay of dead plants and animals
E)about the same;conditions in the soil and atmosphere are similar

Question 24

The maximum water available for plant use after water has drained from the large pore spaces is

A)soil texture.
B)field capacity.
C)permeability.
D)soil structure.
E)porosity.

Question 25

In soil science,the term to describe the cohesion of soil particles is

A)soil texture.
B)permeability.
C)consistence.
D)soil structure.
E)soil moisture.

Question 26

Approximately what percent of farmlands are losing soil quicker than it can be formed?

A)15
B)25
C)35
D)45
E)55

Question 27

A few centimeters' thickness of prime farmland soil may require years to form.

A)10
B)50
C)100
D)250
E)500

Question 28

A roughly equal mix of sand,silt,and clay is called

A)humus.
B)regolith.
C)solum.
D)loam.
E)pedon.

Question 29

The smallest natural lump or cluster of soil particles is known as a

A)horizon.
B)ped.
C)profile.
D)separate.
E)plasticity.

Question 30

Rounded peds have _ space between them than other peds,and are therefore for plant growth.

A)less;better
B)less;worse
C)more;worse
D)more;better
E)equal;neither better nor worse

Question 31

Which of the following human activities does not make soils more prone to erosion?

A)overcultivation
B)overgrazing
C)forest clearance
D)no-till agriculture
E)excessive plowing

Question 32

A plant that is unable to extract needed water from soil has reached its

A)field capacity.
B)permeability.
C)wilting point.
D)porosity.
E)cation-exchange.

Question 33

Why are soil colloids important in soils?

A)Soil colloids are an indication of soil moisture.The higher number of colloids,the greater the soil moisture is.
B)Without colloids,leaching would dissolve important chemicals from the soil,making them unavailable to plant.
C)Soil colloids have a neutralizing effect,increasing the overall alkalinity of soil and making them prime for certain agricultural crops.
D)As one of the shapes of an individual ped,soil colloids control rooting of plants.
E)Soil colloids is a measure of the maximum water available for plants use after the water has drained from large pore spaces.

Question 34

Why is cation-exchange capacity (CEC)an important soil characteristic?

A)CEC is an indication of the soil permeability;the lower the CEC the higher the permeability.
B)CEC is a measure of soil fertility;the higher the CEC the higher the soil fertility.
C)CEC is an indirect way to measure soil pH;it indicates whether the soil is neutral,alkaline,or acidic.
D)CEC is used to infer soil texture without having to use a soil texture triangle.
E)CEC is a measure of all of the chemical properties of soil,providing a single,easy to obtain measurement.

Question 35

Which of the following is correct regarding the color of soil?

A)Dark soils always indicate high organic content.
B)Despite the importance of color in describing soils,there is no standard methods for descriptions.
C)Soil color is used solely to determine the moisture content of soil-darker soils have a higher moisture content,whereas lighter soils have less water content.
D)Color reflects composition and chemical makeup of a soil.
E)There are only a few hues possible for soils,so color is not an important physical characteristic of soils.

Question 36

refers to the size and shape of the aggregates of particles of soil.

A)Soil texture
B)Soil consistence
C)Soil structure
D)Soil plasticity
E)Soil porosity

Question 37

The term used to denote the part of a volume of soil that is filled with air,gases,or water is

A)soil texture.
B)porosity.
C)permeability.
D)soil structure.
E)soil moisture.

Question 38

Acidic soils

A)are exceptionally rare.
B)cause more rapid weathering and leaching of nutrients.
C)tend to be very fertile and excellent for agriculture purposes.
D)are high in calcium,magnesium,potassium,and sodium ions.
E)typically do not require any additional treatment before planting of agricultural crops.

Question 39

Soil texture refers to

A)differing soil colors in a pedon.
B)the mixture and proportions of individual mineral particles.
C)the different soil horizons.
D)the roughness or smoothness of a soil as felt by a human hand.
E)pebbles,gravel,cobble,and other materials greater than 2 mm in diameter found in soils.

Question 40

Soil structure can be defined as which of the following?

A)crumb or granular only
B)platy only
C)blocky only
D)prismatic only
E)crumb or granular,platy,blocky,or prismatic

Question 41

In which of the following areas would one likely find Oxisols?

A)higher latitudes,especially areas dominated by permafrost
B)tropical regions
C)in mountainous areas with steep slopes
D)primarily in grasslands
E)areas with Mediterranean climates

Question 42

In terms of pedogenic regimes,soil acidification associated with forest soils in cool climates is

A)laterization.
B)salinization.
C)calcification.
D)podzolization.
E)gleization.

Question 43

Laterization is likely to occur in

A)humid and warm.
B)areas of high potential evapotranspiration rates.
C)dry climates.
D)areas characterized by sandy soils and coniferous forests.
E)cold,wet climates.

Question 44

In which of the following areas would one likely find Aridisols?

A)northern Europe
B)the selva in Brazil
C)the U.S.southwest
D)marine west coast climates
E)the tundra of North America and northern Europe

Question 45

In terms of pedogenic regimes,the process that concentrates salts in soils in climates with high evapotranspiration is

A)laterization.
B)salinization.
C)calcification.
D)podzolization.
E)gleization.

Question 46

Podzolization is likely to occur in

A)the tropics.
B)areas with broadleaf forests.
C)humid climate regions.
D)areas characterized coniferous forests.
E)cold,wet climates.

Question 47

The practice of leaving crop residue on the field between plantings to help prevent soil erosion is known as

A)slash and burn agriculture.
B)swidden.
C)shifting cultivation.
D)precision agriculture.
E)no-till agriculture.

Question 48

The lowest and most precise level of the U.S.soil classification system is

A)soil family.
B)soil order.
C)soil series.
D)soil great group.
E)soil subgroups.

Question 49

Gleization is likely to occur in

A)the tropics.
B)areas with broadleaf forests.
C)humid climate regions.
D)areas characterized coniferous forests.
E)cold,wet climates.

Question 50

Which of the following is among the most mature soils on Earth?

A)Andisols
B)Inceptisols
C)Entisols
D)Oxisols
E)Gelisols

Question 51

Which of the following is correct about the U.S.soil classification system?

A)Soil variation is too complex for a single classification system,so many regional classification systems are used within the U.S.
B)The Soil Taxonomy is hierarchical,consisting of six categories from soil series to soil order.
C)The soil classification system was finalized in 1975 and no additional changes to it will be made.
D)It is primarily based on pedogenic regimes in which each soil-forming process is attached to a climatic region.
E)Soil order is ranker based on the priority of the soil.

Question 52

In terms of pedogenic regimes,the process that results in an accumulation of humus overlaying a thick,water saturated layer of clay in cold,wet climates with poor drainage conditions is

A)laterization.
B)salinization.
C)calcification.
D)podzolization.
E)gleization.

Question 53

Calcification is likely to occur in

A)areas with Vertisols.
B)areas with arid and semiarid deserts and grasslands.
C)tropical climate regions.
D)areas characterized by coniferous forests.
E)cold,wet climates.

Question 54

Which soil order occupies the most land area worldwide?

A)Oxisols
B)Mollisols
C)Aridisols
D)Andisols
E)Spodosols

Question 55

These mature soils are found in the tropics.

A)Oxisols
B)Mollisols
C)Aridisols
D)Andisols
E)Gelisols

Question 56

The multiyear period of severe wind erosion and soil loss occurred in the Great Plains during the 1930s is known as

A)desertification.
B)the Grapes of Wrath.
C)the Black Blizzard.
D)the Dust Bowl.
E)the Deflation Hollow.

Question 57

In terms of pedogenic regimes,the leaching process in humid and warm climates is known as

A)laterization
B)salinization.
C)calcification.
D)podzolization.
E)gleization.

Question 58

Oxisols have a cation-exchange and,therefore,fertility.

A)high;high
B)low;high
C)low;low
D)high;low
E)moderate;moderate

Question 59

Salinization is likely to occur in

A)the tropics.
B)areas of high potential evapotranspiration rates.
C)humid climate regions.
D)areas characterized by coniferous forests.
E)cold,wet climates.

Question 60

In terms of pedogenic regimes,the process that produces an illuviated accumulation of calcium carbonate in continental climates is

A)laterization.
B)salinization.
C)calcification.
D)podzolization.
E)gleization.

Question 61

Soils with volcanic parent material belong to which soil order?

A)Andisols
B)Histosols
C)Vertisols
D)Gelisols
E)Mollisols

Question 62

These grassland soils are some of the Earth's most significant agricultural soils.

A)Gelisols
B)Molliso1s
C)Aridisols
D)Inceptisols
E)Oxisols

Question 63

are recently developed soils lacking vertical horizon development.

A)Spodosols
B)Entisols
C)Oxisols
D)Mollisols
E)Aridisols

Question 64

The southeast United States is dominated by which soil order?

A)Ultisols
B)Alfisols
C)Oxisols
D)Mollisols
E)Entisols

Question 65

are among the Earth's most agriculturally significant soils.

A)Aridisols
B)Inceptisols
C)Mollisols
D)Entisols
E)Oxisols

Question 66

Where would one must likely find Entisols?

A)stable landscapes
B)areas dominated by permafrost
C)forest floors in eastern deciduous forests
D)the flat to relatively rolling plains of the Midwest
E)active slopes and glacial outwash plains

Question 67

This is the world's largest soil order,occurring on 19% of the Earth's land surface in the world's dry regions.

A)Oxisols
B)Mollisols
C)Aridisols
D)Andisols
E)Spodosols

Question 68

In a west to east transect across the 98th meridian in the United States,which of the following is the correct sequence of soil orders?

A)Alfisols,Aridisols,Ultisols
B)Aridisols,Oxisols,Mollisols
C)Aridisols,Mollisols,Alfisols
D)Alfisols,Mollisols,Ultilsols
E)Spodosols,Entisols,Gelisols

Question 69

These soils are high in expandable clays and found in regions experiencing highly variable soil- moisture balances through the seasons.

A)Oxisols
B)Mollisols
C)Vertisols
D)Aridisols
E)Spodosols

Question 70

These soils are the most spatially widespread,extending from the equator to high latitudes.

A)Vertisols
B)Alfisols
C)Entisols
D)Gelisols
E)Ultisols

Question 71

Which soil order is the most spatially widespread,found from near the equator to high latitudes?

A)Vertisols
B)Alfisols
C)Entisols
D)Gelisols
E)Ultisols

Question 72

In which of the following regions would one likely find Spodosols?

A)savannas and grasslands
B)tropical rainforests
C)northern coniferous forests
D)deserts and semiarid areas
E)high altitude tundra

Question 73

Relatively high precipitation in the regions in which these soils are found cause greater mineral alterations and more alluvial leaching than in other soils.

A)Oxisols
B)Andisols
C)Gelisols
D)Ultisols
E)Entisols

Question 74

Most of the glacially derived till and outwash materials from New York through the Appalachians are

A)Spodosols.
B)Histosols.
C)Inceptisols.
D)Gelisols.
E)Aridisols

Question 75

These soils primarily occur in the northern coniferous forests,but may also occur with more moderate properties under mixed or deciduous forests.

A)Ultisols
B)Inceptisols
C)Entisols
D)Oxisols
E)Spodosols

Question 76

In which of the following areas would one likely find Mollisols?

A)Sub-Saharan Africa
B)the U.S.Great Plains
C)central Africa
D)southeast United States
E)coniferous forests in northern latitudes

Question 77

Expandable clay soils,such as montmorillonite,characterize this soil order.

A)Oxisols
B)Mollisols
C)Vertisols
D)Aridisols
E)Spodosols

Question 78

are high latitude soils containing permafrost and large amounts of organic matter.

A)Alfisols
B)Ultisols
C)Inceptisols
D)Gelisols
E)Spodosols

Question 79

are hydric soils,forming in beds of former lakes and small,poorly drained depressions.

A)Histosols
B)Andisols
C)Vertisols
D)Aridisols
E)Entisols

Question 80

These high latitude,periglacial soils contain about half of the pool of global carbon.

A)Oxisols
B)Spodosols
C)Gelisols
D)Mollisols
E)Aridisols