Question 1

Compared to gypsum,elemental sulfur is sometimes considered a more desirable fertilizer material because _____

Accepted Answer

A) plants respond to sulfur more rapidly 
B) it is less dependent on warm,moist conditions for availability 
C) it contains more nutrient sulfur,kilogram for kilogram,than gypsum 
D) it causes less soil acidity than gypsum 
E) all of the above 
A) plants respond to sulfur more rapidly 
B) it is less dependent on warm,moist conditions for availability 
C) it contains more nutrient sulfur,kilogram for kilogram,than gypsum 
D) it causes less soil acidity than gypsum 
E) all of the above

Question 2

About half the nitrogen in the A horizon of most soils becomes available to plants over the course of a whole year in a warm,humid climate.

Accepted Answer

A) True 
 B)False

Question 3

Applied to agricultural crops,the term lodging refers to ________.

Accepted Answer

A) pre-mature fruit drop as a result of N deficiency 
B) infestation with a high number of insect larvae lodged in the fruits or seeds 
C) short,stubby plants starving for N or S 
D) plants falling over,often as a result of too much N 
E) plants losing their leaves because of a N imbalance 
A) pre-mature fruit drop as a result of N deficiency 
B) infestation with a high number of insect larvae lodged in the fruits or seeds 
C) short,stubby plants starving for N or S 
D) plants falling over,often as a result of too much N 
E) plants losing their leaves because of a N imbalance

Question 4

Ammonia volatilization is a process by which much needed nitrogen is added to the pool of plant-available nitrogen in soils.

Accepted Answer

A) True 
 B)False

Question 5

Because of their huge numbers and direct access to soil organic matter,free living microorganisms such as Azotobacter typically fix more nitrogen per hectare of land than do nitrogen-fixing bacteria living in plant roots.

Accepted Answer

A) True 
 B)False

Question 6

Leguminous forest trees,such as Locust,enrich the soil in nitrogen,to the benefit of non-nitrogen fixing plants growing nearby.

Accepted Answer

A) True 
 B)False

Question 7

Most nitrogen leaching to groundwater is in the form of ammonium.

Accepted Answer

A) True 
 B)False

Question 8

Nitrification requires the presence of a source of readily available carbon,such as manure.

Accepted Answer

A) True 
 B)False

Question 9

Assume an A horizon depth of 15 cm.A well drained silt loam soil on an Iowa farm has 3.5% organic matter which is about 5% N.Estimate the kg/ha of nitrogen that this soil horizon will make available for plant use from soil organic matter in one year (without the addition of fertilizer).

Accepted Answer

A) 17.5 
B) 88 
C) 263 
D) 175 
E) 38 
A) 17.5 
B) 88 
C) 263 
D) 175 
E) 38

Question 10

The sulfur dioxide in the atmosphere ______.

Accepted Answer

A) can be an important source of sulfur nutrition for plants 
B) is a major contributor to "acid rain" 
C) comes from fires such as fossil fuel burning,volcanoes and forest fires 
D) all of the above 
E) none of the above 
A) can be an important source of sulfur nutrition for plants 
B) is a major contributor to "acid rain" 
C) comes from fires such as fossil fuel burning,volcanoes and forest fires 
D) all of the above 
E) none of the above

Question 11

In order for nitrate to form from soil organic matter,_____ must be present in the soil.

Accepted Answer

A) Nitrosomonas 
B) Nitrobacter 
C) either A or B 
D) both A and B 
E) none of the above 
A) Nitrosomonas 
B) Nitrobacter 
C) either A or B 
D) both A and B 
E) none of the above

Question 12

To be practical,a nitrification inhibitor should kill or inhibit _____.

Accepted Answer

A) Nitrosomonas 
B) Nitrobacter 
C) either A or B 
D) none of the above 
A) Nitrosomonas 
B) Nitrobacter 
C) either A or B 
D) none of the above

Question 13

Nitrogen taken up by plants growing in a compost-treated soil is indistinguishable from the nitrogen taken up by plants growing in a fertilizer-treated soil.

Accepted Answer

A) True 
 B)False

Question 14

The opposite process from mineralization is _______.

Accepted Answer

A) immobilization 
B) nitrification 
C) denitrification 
D) ammonification 
E) none of the above 
A) immobilization 
B) nitrification 
C) denitrification 
D) ammonification 
E) none of the above

Question 15

Wetlands and forests growing along the banks of rivers remove much nitrogen from groundwater by the process of _________.

Accepted Answer

A) immobilization 
B) nitrification 
C) denitrification 
D) ammonification 
E) none of the above 
A) immobilization 
B) nitrification 
C) denitrification 
D) ammonification 
E) none of the above

Question 16

The principal form of sulfur taken up by plants is ____.

Accepted Answer

A) sulfate 
B) sulfur esters 
C) sulfides 
D) elemental sulfur 
E) gypsum 
A) sulfate 
B) sulfur esters 
C) sulfides 
D) elemental sulfur 
E) gypsum

Question 17

Unlike Rhizobium bacteria,Bradyrhizobium bacteria are effective at fixing N,regardless of the type of plants present.

Accepted Answer

A) True 
 B)False

Question 18

The great majority of nitrogen (95 to 98%)in soils can be found in the form of _____.

Accepted Answer

A) primary minerals 
B) secondary minerals 
C) dissolved cations 
D) dissolved anions 
E) organic compounds 
A) primary minerals 
B) secondary minerals 
C) dissolved cations 
D) dissolved anions 
E) organic compounds

Question 19

The process of ______ releases soluble nitrogen as the result of the breakdown of nitrogen-rich organic compounds.

Accepted Answer

A) nitrification 
B) denitrification 
C) symbiosis 
D) volatilization 
E) mineralization 
A) nitrification 
B) denitrification 
C) symbiosis 
D) volatilization 
E) mineralization

Question 20

A deficiency of N typically ______ the maturity of annual plants.

Accepted Answer

A) hastens 
B) delays 
C) does not affect 
A) hastens 
B) delays 
C) does not affect

Compared to gypsum,elemental sulfur is sometimes considered a more desirable fertilizer material because _____

About half the nitrogen in the A horizon of most soils becomes available to plants over the course of a whole year in a warm,humid climate.

Applied to agricultural crops,the term lodging refers to ________.

Ammonia volatilization is a process by which much needed nitrogen is added to the pool of plant-available nitrogen in soils.

Because of their huge numbers and direct access to soil organic matter,free living microorganisms such as Azotobacter typically fix more nitrogen per hectare of land than do nitrogen-fixing bacteria living in plant roots.

Leguminous forest trees,such as Locust,enrich the soil in nitrogen,to the benefit of non-nitrogen fixing plants growing nearby.

Most nitrogen leaching to groundwater is in the form of ammonium.

Nitrification requires the presence of a source of readily available carbon,such as manure.

Assume an A horizon depth of 15 cm.A well drained silt loam soil on an Iowa farm has 3.5% organic matter which is about 5% N.Estimate the kg/ha of nitrogen that this soil horizon will make available for plant use from soil organic matter in one year (without the addition of fertilizer).

The sulfur dioxide in the atmosphere ______.

In order for nitrate to form from soil organic matter,_____ must be present in the soil.

To be practical,a nitrification inhibitor should kill or inhibit _____.

Nitrogen taken up by plants growing in a compost-treated soil is indistinguishable from the nitrogen taken up by plants growing in a fertilizer-treated soil.

The opposite process from mineralization is _______.

Wetlands and forests growing along the banks of rivers remove much nitrogen from groundwater by the process of _________.

The principal form of sulfur taken up by plants is ____.

Unlike Rhizobium bacteria,Bradyrhizobium bacteria are effective at fixing N,regardless of the type of plants present.

The great majority of nitrogen (95 to 98%)in soils can be found in the form of _____.

The process of ______ releases soluble nitrogen as the result of the breakdown of nitrogen-rich organic compounds.

A deficiency of N typically ______ the maturity of annual plants.

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

Soil Organic Matter

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 13: Nitrogen and Sulfur Economy of Soils

Compared to gypsum,elemental sulfur is sometimes considered a more desirable fertilizer material because _____

About half the nitrogen in the A horizon of most soils becomes available to plants over the course of a whole year in a warm,humid climate.

Applied to agricultural crops,the term lodging refers to ________.

Ammonia volatilization is a process by which much needed nitrogen is added to the pool of plant-available nitrogen in soils.

Because of their huge numbers and direct access to soil organic matter,free living microorganisms such as Azotobacter typically fix more nitrogen per hectare of land than do nitrogen-fixing bacteria living in plant roots.

Leguminous forest trees,such as Locust,enrich the soil in nitrogen,to the benefit of non-nitrogen fixing plants growing nearby.

Most nitrogen leaching to groundwater is in the form of ammonium.

Nitrification requires the presence of a source of readily available carbon,such as manure.

Assume an A horizon depth of 15 cm.A well drained silt loam soil on an Iowa farm has 3.5% organic matter which is about 5% N.Estimate the kg/ha of nitrogen that this soil horizon will make available for plant use from soil organic matter in one year (without the addition of fertilizer).

The sulfur dioxide in the atmosphere ______.

In order for nitrate to form from soil organic matter,_____ must be present in the soil.

To be practical,a nitrification inhibitor should kill or inhibit _____.

Nitrogen taken up by plants growing in a compost-treated soil is indistinguishable from the nitrogen taken up by plants growing in a fertilizer-treated soil.

The opposite process from mineralization is _______.

Wetlands and forests growing along the banks of rivers remove much nitrogen from groundwater by the process of _________.

The principal form of sulfur taken up by plants is ____.

Unlike Rhizobium bacteria,Bradyrhizobium bacteria are effective at fixing N,regardless of the type of plants present.

The great majority of nitrogen (95 to 98%)in soils can be found in the form of _____.

The process of ______ releases soluble nitrogen as the result of the breakdown of nitrogen-rich organic compounds.

A deficiency of N typically ______ the maturity of annual plants.

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

Soil Organic Matter

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