Deck 15: Soil Development and Soil Profiles

Question 1

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

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

Answer 1

B

Question 2

Which of the following best describes soil?

A)Soil is composed of solely mineral fragments less than 2 mm in size.
B)Soil is a renewable resource.
C)Soil lacks biological material.
D)Soil is a dynamic natural material composed of water,air,mineral fragments,and organic matter.

Answer 2

D

Question 3

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

A)Plant roots provide channels for air and water movement in soils.
B)Broadleaf trees tend to increase the alkalinity of soil,whereas needleleaf trees increase the acidity.
C)Earthworms increase soil porosity and contribute to soil movement and organic content.
D)All organisms living in,on,and over the soil,influence soil development and characteristics: they can influence the pH,the organic matter,chemical content,and biological content of soils.

Answer 3

D

Question 4

Where would one likely find the deepest soil development?

A)Over the oldest geological formations in an area,regardless of slope
B)On steep slopes
C)Level or nearly level ground
D)Moderately sloping,south facing hills

Question 5

The horizon that is commonly called topsoil is the horizon.

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

Question 6

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

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

Question 7

The horizon identified as regolith is the horizon.

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

Question 8

Which of the following is CORRECT regarding loess deposits?

A)They are formed of fine-grained clays,silts,and fine sands.
B)They only form following glacial activity.
C)They are found only in the United States.
D)They are principally composed of sands and gravels.

Question 9

The basic soil sampling unit is

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

Question 10

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

A)Temperature
B)Moisture
C)Color
D)Porosity
E)Texture

Question 11

The branch of soil science that studies soil as a medium for sustaining the growth of higher plants is known as

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

Question 12

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

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

Question 13

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 14

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

A)Relative humidity and atmospheric pressure are the dominant climatic factors that influence soil development.
B)Temperature and moisture determine the chemical reactions,organic activity,and water movement within soils.
C)Because all soils are ancient,they show the climatic conditions of the period in which they formed.
D)Of the five principle soil-forming factors,climate is the least significant with little correlation between soil and climates worldwide.

Question 15

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

A)Biological activity
B)Climate
C)Topography
D)Human activity
E)Parent material

Question 16

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 17

Which of the following best describes the composition of soil?

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

Question 18

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)polypedon.
B)soil profile.
C)pedon.
D)soil horizon.

Question 19

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

A)Warm and humid
B)Hot and dry
C)Cold and dry
D)In areas where they can develop directly from bedrock,regardless of climate conditions

Question 20

The horizon in which leached materials are accumulated is the horizon.

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

Question 21

Prime farmland soil that is a few centimeters thick may require years to form.

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

Question 22

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 Dust Bowl.
D)the Black Blizzard.

Question 23

Soil texture refers to

A)pebbles,gravel,cobble,and other materials greater than 2 mm in diameter.
B)the different soil horizons.
C)differing soil colors in a pedon.
D)the mixture and proportions individual mineral particles.

Question 24

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

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

Question 25

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

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

Question 26

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

A)less; worse
B)more; better
C)more; worse
D)less; better

Question 27

Soil structure can be defined as which of the following?

A)prismatic
B)crumb or granular
C)platy
D)blocky
E)Crumb or granular,platy,blocky,or prismatic are all type of soil structure.

Question 28

Carbon dioxide concentrations in soil are than in the atmosphere because of .

A)higher; decay of dead plants and animals
B)higher; ongoing respiration in the ground
C)lower; transpiration
D)lower; plant photosynthesis

Question 29

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

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

Question 30

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

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

Question 31

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

A)porosity.
B)wilting point.
C)field capacity.
D)permeability.

Question 32

Which of the following human activities may make soils more prone to erosion?

A)forest clearance
B)overcultivation
C)overgrazing
D)Overcultivation,overgrazing,and forest clearance may all make soils more prone to erosion.

Question 33

The phenomenon of desert expansion along the margins of semiarid and arid lands is known as

A)deflation.
B)desertification.
C)permeability.
D)erosion.

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 used to infer soil texture without having to use a soil texture triangle.
D)CEC is an indirect way to measure soil pH; it indicates whether the soil is neutral,alkaline,or acidic.

Question 35

Ped formation enhances

A)soil texture.
B)soil horizons.
C)plasticity.
D)permeability.

Question 36

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

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

Question 37

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)no-till agriculture.
C)shifting cultivation.
D)swidden.

Question 38

Acidic soils

A)are exceptionally rare.
B)are high in calcium,magnesium,potassium,and sodium ions.
C)cause more rapid weathering and leaching of nutrients.
D)tend to be very fertile and excellent for agriculture purposes.

Question 39

Which of the following is CORRECT regarding soil color?

A)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.
B)Color reflects composition and chemical makeup of a soil.
C)Soil color is a relatively unimportant physical property of soil.
D)Dark soils always indicate high organic content.

Question 40

Between 1982 and 2007,soil erosion on U.S.cropland

A)increased by 25%
B)decreased by 43%.
C)decreased by 21%.
D)increased by 13%.

Question 41

The pedogenic process that produces an illuviated accumulation of calcium carbonate in continental climates is

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

Question 42

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

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

Question 43

Laterization is likely to occur

A)in the tropics.
B)in humid climate regions.
C)in areas characterized by sandy soils and coniferous forests.
D)in areas of high potential evapotranspiration rates.

Question 44

Salinization is likely to occur

A)in humid climate regions.
B)in the tropics.
C)in areas of high potential evapotranspiration.
D)in areas characterized by coniferous forests.

Question 45

Soil science is an interdisciplinary study,drawing on aspects of physics,chemistry,biology,mineralogy,hydrology,taxonomy,climatology,and cartography.

Question 46

The pedogenic process that concentrates salts in soils in climates with high evapotranspiration is

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

Question 47

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

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

Question 48

Calcification is likely to occur in

A)areas with Vertisols.
B)tropical climate regions.
C)arid,semiarid,and grassland environments.
D)areas characterized by coniferous forests.

Question 49

In the Northern Hemisphere,north facing slopes are generally colder,have slower snowmelt,lower evapotranspiration rates,and more moisture for plants than south facing slopes do.

Question 50

Soils are remarkably uniform from the surface to bedrock.

Question 51

Human activities,such as agriculture and cattle grazing,may affect soil development.

Question 52

Each differing and distinct mineral and organic strata within a soil column is called a horizon.

Question 53

All organisms living in,on,and over the soil influence its organic content and chemical characteristics.

Question 54

The O horizon is typically lacking in organic matter.

Question 55

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

Question 56

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

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

Question 57

Soil tends to develop profiles that are deeper on steep slopes than on level ground.

Question 58

Podzolization is likely to occur

A)in areas with broadleaf forests.
B)in humid climate regions.
C)in areas characterized coniferous forests.
D)in the tropics.

Question 59

Soil is composed of 70% mineral matter,5% organic matter,and varying amounts of water and air totaling 25%.

Question 60

Broadleaf trees tend to increase the acidity of soils.

Question 61

Soils with a high concentration of hydrogen ions (H+)are considered alkaline.

Question 62

Rounded peds have more pore space and permeability than do other ped shapes.

Question 63

A high cation-exchange capacity (CEC)tends to indicate poor soil fertility.

Question 64

A dark colored soil always indicates high organic content.

Question 65

Over 15,000 soil series have been classified up to this time in the United States and Canada.

Question 66

Between 1982 to 2007,there was actually a decrease in soil erosion on U.S.cropland.

Question 67

The Soil Taxonomy is a hierarchical system consisting of six categories.

Question 68

Biological activity by plant roots or tunnelling animals tends to diminish porosity.

Question 69

In addition to designating horizons,soil scientists also identify subhorizons,such as those for human activity or the presence of organic matter.

Question 70

Oxygen concentrations are lower in soil than in atmospheric oxygen due to ongoing respiration processes in the ground.

Question 71

Before the U.S.Soil Taxonomy system,soils were classified based on pedogenic regimes.

Question 72

Practices such as no-till agriculture may help mitigate against soil erosion.

Question 73

The U.S.soil classification system has not been updated since the mid-1970s.

Question 74

Inceptisols are the largest single soil order,occupying approximately 22% of Earthʹs land surface.

Question 75

Soil texture is probably the most permanent property of a soil.

Question 76

Prime farmland soil that is a few centimeters thick may require 500 years to mature.

Question 77

Desertification is affecting over a billion people worldwide.

Question 78

A soil order is the lowest and most precise level of the Soil Taxonomy system.

Question 79

The A horizon is also commonly called topsoil.

Question 80

Though Oxisols occur in the tropical rain forests,they tend to be poor in inorganic nutrients.