Question 1

Which of the following pools contain the largest amount of the world's carbon?

Accepted Answer

A) soil 
B) vegetation 
C) atmosphere 
D) animals 
A) soil 
B) vegetation 
C) atmosphere 
D) animals A

Question 2

Microbial metabolism in the guts of termites and in waterlogged soils are two major sources of excess methane that is contributing to the global greenhouse effect.

Accepted Answer

A) True 
 B)False  True

Question 3

Biomass consists of ______.

Accepted Answer

A) living organisms and cells 
B) dead tissues and wastes 
C) identifiable biomolecules 
D) polymerized,non-identifiable molecules 
E) all of the above 
A) living organisms and cells 
B) dead tissues and wastes 
C) identifiable biomolecules 
D) polymerized,non-identifiable molecules 
E) all of the above A

Question 4

The soils of the world contain more carbon than all the world's vegetation and the entire atmosphere,combined.

Accepted Answer

A) True 
 B)False

Question 5

The cation capacity of soil humus is two to three times greater than that of an equal volume of high CEC silicate clays.

Accepted Answer

A) True 
 B)False

Question 6

In the United States,a national goal of maintaining 5% organic matter in all agricultural soils would be a practical and beneficial policy in the long term.

Accepted Answer

A) True 
 B)False

Question 7

The labile organic matter in the soil consists of ____.

Accepted Answer

A) living organisms and cells 
B) dead tissues and wastes 
C) identifiable biomolecules 
D) A and B 
E) all of the above 
A) living organisms and cells 
B) dead tissues and wastes 
C) identifiable biomolecules 
D) A and B 
E) all of the above

Question 8

Sandy soils generally are higher in organic matter than fine textured soils.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following is a greenhouse gas contributed to the atmosphere by soils?

Accepted Answer

A) nitrous oxides 
B) carbon dioxide 
C) methane 
D) all of the above 
E) none of the above 
A) nitrous oxides 
B) carbon dioxide 
C) methane 
D) all of the above 
E) none of the above

Question 10

To avoid a nitrate depression period when it is added to a garden soil,about how many kg of nitrogen must be added to a load of grass clippings that contains 1000 kg of C and 25 kg of N?

Accepted Answer

A) 15 
B) 35 
C) 50 
D) 75 
E) 100 
A) 15 
B) 35 
C) 50 
D) 75 
E) 100

Question 11

Removing all the straw with the harvest of paddy rice would increase the amount of methane produced by the paddy soil microorganisms.

Accepted Answer

A) True 
 B)False

Question 12

Under natural vegetation,about 60 to 90% of soil organic matter is in the _____fraction.

Accepted Answer

A) active 
B) slow 
C) passive 
A) active 
B) slow 
C) passive

Question 13

Nearly all organic compounds from which living beings are made have as their backbone,chains or rings of _____ atoms.

Accepted Answer

A) aluminum 
B) oxygen 
C) carbon 
D) nitrogen 
E) none of the above 
A) aluminum 
B) oxygen 
C) carbon 
D) nitrogen 
E) none of the above

Question 14

When fresh plant residues are added to soils,the "priming effect" may result in the decomposition of _______.

Accepted Answer

A) stable humus 
B) sugars and starch 
C) waxes and fats 
D) lignin and cellulose 
E) proteins and other nitrogen-rich compounds 
A) stable humus 
B) sugars and starch 
C) waxes and fats 
D) lignin and cellulose 
E) proteins and other nitrogen-rich compounds

Question 15

When native prairie soils are brought under cultivation,the fraction of soil organic matter which disappears most quickly is the passive fraction.

Accepted Answer

A) True 
 B)False

Question 16

The active fraction of soil organic matter largely accounts for which of the benefits of adding organic matter to soils?

Accepted Answer

A) increased CEC 
B) increased water holding capacity 
C) increased microbial activity 
D) increased aggregate stability 
E) both c and d 
A) increased CEC 
B) increased water holding capacity 
C) increased microbial activity 
D) increased aggregate stability 
E) both c and d

Question 17

Practices that increase the soil organic matter level generally have favorable effects on the chemical and biological properties of soils,but have little or no effect on soil physical properties.

Accepted Answer

A) True 
 B)False

Question 18

Well aerated soils enriched with organic amendments can help reduce the methane load in the atmosphere.

Accepted Answer

A) True 
 B)False

Question 19

Soil humus is made up primarily of complex microbially produced supermolecule polymers known as humic substances.

Accepted Answer

A) True 
 B)False

Question 20

Green plant residues such as grass clippings or a green manure crop generally have a water content of about ____% by weight.

Accepted Answer

A) 10 
B) 25 
C) 45 
D) 75 
E) 95 
A) 10 
B) 25 
C) 45 
D) 75 
E) 95

Which of the following pools contain the largest amount of the world's carbon?

Microbial metabolism in the guts of termites and in waterlogged soils are two major sources of excess methane that is contributing to the global greenhouse effect.

Biomass consists of ______.

The soils of the world contain more carbon than all the world's vegetation and the entire atmosphere,combined.

The cation capacity of soil humus is two to three times greater than that of an equal volume of high CEC silicate clays.

In the United States,a national goal of maintaining 5% organic matter in all agricultural soils would be a practical and beneficial policy in the long term.

The labile organic matter in the soil consists of ____.

Sandy soils generally are higher in organic matter than fine textured soils.

Which of the following is a greenhouse gas contributed to the atmosphere by soils?

To avoid a nitrate depression period when it is added to a garden soil,about how many kg of nitrogen must be added to a load of grass clippings that contains 1000 kg of C and 25 kg of N?

Removing all the straw with the harvest of paddy rice would increase the amount of methane produced by the paddy soil microorganisms.

Under natural vegetation,about 60 to 90% of soil organic matter is in the _____fraction.

Nearly all organic compounds from which living beings are made have as their backbone,chains or rings of _____ atoms.

When fresh plant residues are added to soils,the "priming effect" may result in the decomposition of _______.

When native prairie soils are brought under cultivation,the fraction of soil organic matter which disappears most quickly is the passive fraction.

The active fraction of soil organic matter largely accounts for which of the benefits of adding organic matter to soils?

Practices that increase the soil organic matter level generally have favorable effects on the chemical and biological properties of soils,but have little or no effect on soil physical properties.

Well aerated soils enriched with organic amendments can help reduce the methane load in the atmosphere.

Soil humus is made up primarily of complex microbially produced supermolecule polymers known as humic substances.

Green plant residues such as grass clippings or a green manure crop generally have a water content of about ____% by weight.

The Soils Around Us

Formation of Soils From Parent Materials

Soil Classification

Soil Architecture and Physical Properties

Soil Water: Characteristics and Behavior

Soil and the Hydrologic Cycle

Soil Aeration and Temperature

The Colloidal Fraction: Seat of Soil Chemical and Physical Activity

Soil Acidity

Soils of Dry Regionsalkalinity,salinity and Sodicity

Organisms and Ecology of the Soil

Nitrogen and Sulfur Economy of Soils

Soil Phosphorus and Potassium

Calcium,magnesium and Trace Elements

Practical Nutrient Management

Soil Erosion and Its Control

Soils and Chemical Pollution

Geographic Information About Soils

Prospects for Global Soil Quality As Affected by Human Activities

Filters

Exam 12: Soil Organic Matter

Which of the following pools contain the largest amount of the world's carbon?

Microbial metabolism in the guts of termites and in waterlogged soils are two major sources of excess methane that is contributing to the global greenhouse effect.

Biomass consists of ______.

The soils of the world contain more carbon than all the world's vegetation and the entire atmosphere,combined.

The cation capacity of soil humus is two to three times greater than that of an equal volume of high CEC silicate clays.

In the United States,a national goal of maintaining 5% organic matter in all agricultural soils would be a practical and beneficial policy in the long term.

The labile organic matter in the soil consists of ____.

Sandy soils generally are higher in organic matter than fine textured soils.

Which of the following is a greenhouse gas contributed to the atmosphere by soils?

To avoid a nitrate depression period when it is added to a garden soil,about how many kg of nitrogen must be added to a load of grass clippings that contains 1000 kg of C and 25 kg of N?

Removing all the straw with the harvest of paddy rice would increase the amount of methane produced by the paddy soil microorganisms.

Under natural vegetation,about 60 to 90% of soil organic matter is in the _____fraction.

Nearly all organic compounds from which living beings are made have as their backbone,chains or rings of _____ atoms.

When fresh plant residues are added to soils,the "priming effect" may result in the decomposition of _______.

When native prairie soils are brought under cultivation,the fraction of soil organic matter which disappears most quickly is the passive fraction.

The active fraction of soil organic matter largely accounts for which of the benefits of adding organic matter to soils?

Practices that increase the soil organic matter level generally have favorable effects on the chemical and biological properties of soils,but have little or no effect on soil physical properties.

Well aerated soils enriched with organic amendments can help reduce the methane load in the atmosphere.

Soil humus is made up primarily of complex microbially produced supermolecule polymers known as humic substances.

Green plant residues such as grass clippings or a green manure crop generally have a water content of about ____% by weight.

The Soils Around Us

Formation of Soils From Parent Materials

Soil Classification

Soil Architecture and Physical Properties

Soil Water: Characteristics and Behavior

Soil and the Hydrologic Cycle

Soil Aeration and Temperature

The Colloidal Fraction: Seat of Soil Chemical and Physical Activity

Soil Acidity

Soils of Dry Regionsalkalinity,salinity and Sodicity

Organisms and Ecology of the Soil

Nitrogen and Sulfur Economy of Soils

Soil Phosphorus and Potassium

Calcium,magnesium and Trace Elements

Practical Nutrient Management

Soil Erosion and Its Control

Soils and Chemical Pollution

Geographic Information About Soils

Prospects for Global Soil Quality As Affected by Human Activities

Filters