Deck 14: Soil Resources

Question 1

The deposition of leached material in the lower layers of the soil is called:

A) illuviation.
B) leaching.
C) deposition.
D) decomposition.
E) decompression.

Answer 1

A

Question 2

In soil, the smallest particles (less than .002mm) are called:

A) sand.
B) silt.
C) parent material.
D) clay.
E) illuviation particles.

Answer 2

D

Question 3

The ____________ contains weathered pieces of rock and is found just above the solid bedrock.

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

Answer 3

C

Question 4

Humus is composed of:

A) weathered rocks
B) fresh leaf litter
C) iron and aluminum compounds.
D) decomposed organic matter.
E) various inorganic minerals.

Question 5

The uppermost layer of soil that is rich in plant litter and other organic material is the:

A) A horizon.
B) B horizon.
C) C horizon.
D) O horizon.
E) E horizon.

Question 6

_________ describes the pathway of various nutrient minerals or elements from the environment through organisms and back to the environment.

A) Crop rotation
B) Leaching and illuviation
C) Mycorrhizae
D) Nutrient cycling
E) none of these choices is correct

Question 7

Soil is formed from parent material by biological, chemical, and physical:

A) digestion processes.
B) weathering processes.
C) composting.
D) terracing.
E) leaching.

Question 8

Soil is composed of:

A) mineral particles.
B) organic materials.
C) air.
D) water.
E) All of these

Question 9

The soils of tropical rain forests tend to be nutrient-poor due to:

A) extensive wind erosion.
B) the fact that nutrient minerals are stored primarily in the vegetation.
C) removal of native plants, largely grasses, depleting the nutrient minerals.
D) sediment washing into streams from intact forests.
E) poor crop rotation practices in slash-and-burn agriculture.

Question 10

A(n) _________ is a type of soil that forms in tropical and subtropical regions where organic material decomposes so fast there is very little A-horizon.

A) mollisol.
B) oxisol.
C) aridisol.
D) alfisol.
E) spodosol.

Question 11

Worldwide, 75 billion metric tons (83 billion tons) of topsoil is lost annually, primarily due to:

A) poor agricultural practices.
B) global warming.
C) ozone depletion.
D) the soil rustler's black market.
E) conservation tillage.

Question 12

Water tends to drain rapidly through soil that is high in:

A) sand.
B) silt.
C) humus.
D) clay.
E) illuviation particles.

Question 13

The removal of dissolved minerals from the soil as water moves downward is called:

A) illuviation.
B) leaching.
C) deposition.
D) decomposition.
E) weathering.

Question 14

Which of the following sequences is in the correct order from largest particle size to smallest particle size?

A) Sand > Silt > Gravel > Clay
B) Sand > Gravel > Clay > Silt
C) Gravel > Sand > Clay > Silt
D) Gravel > Sand > Silt > Clay
E) Clay > Silt > Gravel > Sand

Question 15

The ____________ is a lighter-colored soil layer where iron and aluminum often accumulate.

A) A horizon.
B) B horizon.
C) C horizon.
D) O horizon.
E) E horizon.

Question 16

Clay content is particularly important in soil because high-clay soils:

A) provide excellent drainage
B) have large surface areas that can "hold" mineral ions for plant use
C) contain abundant oxygen
D) are ideal for most agricultural crops
E) are easy to till for agriculture

Question 17

Loam:

A) contains about 40% each of sand and silt.
B) is an ideal agricultural soil.
C) has good aeration and drainage.
D) has a medium ability to hold nutrients and water.
E) All of these choices are correct

Question 18

A(n) ___________ is a type of soil that usually forms in colder climates beneath coniferous forests and makes poor farm land because it is often too acidic and nutrient poor.

A) mollisol.
B) oxisol.
C) aridisol.
D) alfisol.
E) spodosol.

Question 19

A(n) __________ is a type of soil that forms in temperate deciduous forests, has a highly leached A-horizon, and must be fertilized if cleared for farmland.

A) mollisol.
B) oxisol.
C) aridisol.
D) alfisol.
E) spodosol.

Question 20

Which of the following may affect the mineral composition of soil?

A) soil age
B) soil pH
C) soil organisms
D) parent material
E) All of these

Question 21

The American Dust Bowl was caused by all of the following except:

A) the fact that the Great Plains of North America have low annual precipitation.
B) the extensive removal of native prairie grasses to plant crops.
C) overgrazing.
D) unusually severe wind and storm conditions.
E) the poor (nutrient) quality of the soil of the Great Plains.

Question 22

Mulch:

A) helps to control weeds.
B) reduces evaporation.
C) extends the growing season.
D) decreases soil erosion.
E) All of these choices are correct

Question 23

Soil with a pH of 6.0:

A) is slightly acidic
B) is most likely caused by human-produced air pollution
C) is problematic because the optimum soil pH for plant growth is 8.0 to 10.0
D) is often associated with toxic concentrations of soluble aluminum and manganese.
E) All of these choices are correct

Question 24

Which of the following authorized the formation of the Soil Conservation Service (now called the
Natural Resources Conservation Service)?

A) Hugh H. Bennett
B) Soil Conservation Act of 1935
C) Food Security Act (Farm Bill) of 1985
D) The Conservation Reserve Program
E) Federal Agriculture Improvement and Reform Act (Farm Bill) of 1996

Question 25

An important plant to use in crop rotation because of its association with nitrogen-fixing bacteria is:

A) corn.
B) wheat.
C) oats.
D) alfalfa.
E) potatoes.

Question 26

Organic fertilizers:

A) have nutrients immediately available to plants.
B) can consist of manure, crop residues, or bone meal.
C) are quickly leached out of the soil by rain.
D) are manufactured.
E) have minimal effect on the production of a given crop.

Question 27

Legume plants like soybeans add which of the following to the soil?

A) sulfur
B) nitrogen
C) trace minerals
D) phosphorus
E) potassium

Question 28

Soil erosion:

A) may result in decreased water quality for fishes and other aquatic organisms.
B) does not reduce the fertility of the soil, just the quantity.
C) is exclusively linked to human activities.
D) is not affected by the extent of plant cover.
E) is never responsible for or related to water pollution.

Question 29

Compost is:

A) a natural fertilizer
B) used to minimize soil erosion.
C) placed on the soil surface when used.
D) used to minimize water loss from the soil.
E) used to control weeds.

Question 30

Scientists know relatively little about the roles of most soil organisms because

A) very few soil organisms have been identified
B) it is hard to study them in a natural environment
C) they are too small to see, even with high-powered microscopes
D) they do not affect soil much and are not worth studying
E) none of these; scientists have a good understanding of most soil organisms

Question 31

A major problem with conservation tillage is:

A) the soil becomes compact.
B) soil erosion increases.
C) it increases insect populations.
D) it requires greater use of herbicides to control weeds.
E) the soil contains less organic matter.

Question 32

Soil pH is important because:

A) some mineral ions are leached more easily from an acidic soil
B) plants cannot survive in soils with pH less than about 4.0.
C) moderately basic soil is ideal for plant growth.
D) plants can only absorb insoluble forms of mineral elements
E) All of these choices are correct.

Question 33

Which of the following two regions have the largest land areas with extensive soil damage?

A) Europe and Asia
B) North and South America
C) Africa and Asia
D) Europe and South America
E) Africa and North America

Question 34

Increased soil erosion may be caused by all of the following except:

A) construction of buildings.
B) construction of roads.
C) construction of shelterbelts.
D) clearcutting large forested areas.
E) agriculture.

Question 35

Which of the following outlines a typical crop rotation planting schedule?

A) corn → oats → corn → alfalfa
B) corn → soybean → oats → corn
C) soybean → corn → oats → corn
D) oats → soybean → oats → corn
E) corn → alfalfa → oats → soybean

Question 36

Planting the same crop year after year:

A) increases damage by insects and disease.
B) decreases soil erosion.
C) does not deplete essential nutrients from the soil.
D) will slowly increase crop yields.
E) is a new and innovative agricultural practice.

Question 37

Which of the following statements about minerals in soil is true?

A) There are only two mineral ions, potassium and magnesium, that are essential for plant growth.
B) Negatively charged mineral ions are often washed out of the root zone.
C) Clay minerals are usually positively charged.
D) Clay minerals very rarely have charged ions
E) Clay particles may "hold" mineral ions in the soil and prevent their use by plants.

Question 38

Of the following, which has the greatest permeability?

A) clay
B) loam
C) sand
D) silt
E) humus

Question 39

The desertification of the Sahel is caused by:

A) overgrazing.
B) overcultivation.
C) periodic droughts.
D) soil erosion.
E) All of these choices are correct

Question 40

Which of the following is not true of conservation tiling?

A) a method of cultivation in which residues from previous crops are left in the soil
B) residues are partially covering soil and helping it to hold seeds
C) there are several types including no tilling
D) over 70% of US farmland was planted using conservation tilling in the early 2000s
E) all these are false

Question 41

What steps can be taken to reclaim soils damaged by erosion? Include information about at least two specific geographic regions and two different actions in your response.

Question 42

Compare and contrast the use of organic and commercial inorganic fertilizers. Which type is more cost effective? Which type is more environmentally friendly? Which type is the most effective overall? Justify your answers.

Question 43

Which soil horizons are most prone to erosion?

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

Question 44

What is humus? Briefly explain why it is important for the soil.

Question 45

The difference between compost and mulch is:

A) compost is mixed into soil to improve fertility; mulch is placed on soil's surface to control weeds and retain moisture.
B) compost is made of inorganic materials; mulch is made of organic materials.
C) compost is used in landfills, individual property owners use mulch.
D) composting is an expensive commercial process; mulching is a do-it-yourself endeavor.
E) There is no difference. Mulch and compost are synonyms.

Question 46

Which of the following is a type of contour plowing?

A) strip cropping
B) native prairie seizure
C) grasslands reserve program
D) sod busting
E) crop rotation

Question 47

Which of the following represents an "ecosystem service" performed by soil organisms?

A) maintaining soil fertility by decaying and cycling organic material
B) providing minerals by assisting in weathering
C) altering topography by amplifying erosion
D) preserving toxic materials by situating toxins into encapsulated structures
E) contributing to desertification by removing excess moisture from the soil

Question 48

Identify the major components of soil and discuss the role of each in the support of living organisms. How do differences in the composition of the soil affect the productivity of a particular region?

Question 49

Crop rotation and strip cropping alternate crops such as corn and wheat. The difference is:

A) In strip cropping, the crops are alternated by size. In crop rotation, the crops are alternated by color.
B) In strip cropping, one crop is exposed and the other covered. In crop rotation, dual crops form concentric circles.
C) In strip cropping, one crop transforms into the other by genetic seed manipulation. In crop rotation, each crop is alternated according to the type of pollinator required.
D) In strip cropping, the crops are alternated by row. In crop rotation, the crops are alternated by years.
E) There is no difference. Crop rotation is another word for strip cropping.

Question 50

Variations in precipitation, local vegetation, parent material, and soil age result in differences in soil types. Using these variables, explain why mollisols are richer soils than oxisols.

Question 51

Soil degradation is primarily attributed to:

A) wildfires, surplus soil organisms and dense vegetation.
B) poor agricultural practices, overgrazing and deforestation.
C) erosion, excessive tillage and coastal location.
D) exhaustion of parent material, severe climate and leaching.
E) heavy rainfall, agroforestry and crop rotation.

Question 52

Rank the relative size of soil particles from smallest to largest.
I. sand
II. clay
III. gravel
IV. silt

A) I - II - III - IV
B) IV - III - II - I
C) II - I - IV - III
D) II - IV - I - III
E) IV - I - II - III

Question 53

The richest farming soils that form under the grasslands of central North America and under moist deciduous forests are the:

A) spodosols and oxisols.
B) aridisols and mollisols.
C) mollisols and alfisols.
D) sunisols and texsols.
E) oxisols and ultisols.

Question 54

Imagine that you are a farmer. Write a journal entry that outlines the conditions that led to the Food Security Act (Farm Bill) of 1985. While you agree in principle with the Conservation Reserve Program of this bill, you've discovered a loophole that would be financially profitable for you. Present in your journal the argument you are having with yourself: the pros and cons associated with compliance with this program.

Question 55

The 1930's Dust Bowl in the western United States is an example of:

A) prolonged drought and accelerated wind erosion caused by use of marginal land for agriculture.
B) the use of flood plains for agriculture leading to desertification.
C) the natural cycle of climate disasters in that region.
D) the relationship between economics and annual precipitation.
E) human activities not being the cause of or accentuating soil problems.

Question 56

In the United States, agricultural practices have been modified in support of soil conservation. Identify two specific problems and the policies or actions that have been implemented to reduce the effect of each on soil conservation. Are there any drawbacks to these solutions?

Question 57

Why is clay particularly important in determining many soil characteristics?
I. clay particles have the smallest surface area relative to other soil particles
II. each clay particle has negative electrical charge on its outer surface to attract mineral ions
III clay is the most porous of the soil particles
IV. clay is the largest of the soil particles

A) I
B) II
C) III
D) IV
E) I and II