Question 1

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

Accepted Answer

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 2

Of the following, which has the greatest permeability?

Accepted Answer

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

Question 3

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

Accepted Answer

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 4

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

Accepted Answer

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

Question 5

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

Accepted Answer

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

Question 6

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

Accepted Answer

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

Question 7

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.

Accepted Answer

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

Question 8

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

Accepted Answer

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 9

Humus is composed of:

Accepted Answer

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

Question 10

Organic fertilizers:

Accepted Answer

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 11

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?

Accepted Answer

The answer of In the United States, agricultural practices have...

Question 12

Soil degradation is primarily attributed to:

Accepted Answer

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 13

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

Accepted Answer

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

Question 14

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

Accepted Answer

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 15

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.

Accepted Answer

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

Question 16

Soil pH is important because:

Accepted Answer

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 17

A major problem with conservation tillage is:

Accepted Answer

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.

Exam 14: Soil Resources

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

Of the following, which has the greatest permeability?

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

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

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

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

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.

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

Humus is composed of:

Organic fertilizers:

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?

Soil degradation is primarily attributed to:

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

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

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.

Soil pH is important because:

A major problem with conservation tillage is: