Question 1

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

Accepted Answer

A) True 
 B)False  False

Question 2

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

Accepted Answer

A) True 
 B)False  False

Question 3

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 A

Question 4

Ammonium fixation occurs to the greatest extent in the O and A horizons.

Accepted Answer

A) True 
 B)False

Question 5

Plants obtain nitrogen from the soil by taking up ______.

Accepted Answer

A) soluble anions 
B) soluble cations 
C) soluble organic compounds 
D) all of the above 
E) none of the above 
A) soluble anions 
B) soluble cations 
C) soluble organic compounds 
D) all of the above 
E) none of the above

Question 6

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 7

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 8

Soluble organic N compounds are taken up by plants and are lost in leaching and runoff waters.

Accepted Answer

A) True 
 B)False

Question 9

The natural microbial oxidation of nitrogen released by organic matter mineralization is a major source of soil acidity.

Accepted Answer

A) True 
 B)False

Question 10

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 11

Nitrogen is a component of which essential plant compounds?

Accepted Answer

A) proteins 
B) chlorophyll 
C) enzymes 
D) DNA 
E) all of the above 
A) proteins 
B) chlorophyll 
C) enzymes 
D) DNA 
E) all of the above

Question 12

Ammonia losses from the shallow, algae-filled water of a non-tidal wetland are likely to be much greater at night than during the day.

Accepted Answer

A) True 
 B)False

Question 13

Although slow release fertilizers take longer to have an effect, they are more economical than regular nitrogen fertilizers and so are favored by foresters and farmers.

Accepted Answer

A) True 
 B)False

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

Ammonium fixation would be expected to be greatest in soils containing a lot of______.

Accepted Answer

A) Rhizobium bacteria 
B) Frankia 
C) vermiculite 
D) iron oxides 
E) both C and D 
A) Rhizobium bacteria 
B) Frankia 
C) vermiculite 
D) iron oxides 
E) both C and D

Question 16

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 17

In the early stages of plant nitrogen deficiency, the most obvious symptoms are _____.

Accepted Answer

A) yellowing of the youngest leaves 
B) brown spots and tiny holes on the underside of most leaves 
C) purpling of the youngest leaves 
D) yellowish colors in the oldest leaves 
E) brown edges on leaves scattered randomly all over the plant 
A) yellowing of the youngest leaves 
B) brown spots and tiny holes on the underside of most leaves 
C) purpling of the youngest leaves 
D) yellowish colors in the oldest leaves 
E) brown edges on leaves scattered randomly all over the plant

Question 18

The terms "ammonium fixation" and "biological nitrogen fixation" refer to the same soil process.

Accepted Answer

A) True 
 B)False

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

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

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

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

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

Ammonium fixation occurs to the greatest extent in the O and A horizons.

Plants obtain nitrogen from the soil by taking up ______.

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

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

Soluble organic N compounds are taken up by plants and are lost in leaching and runoff waters.

The natural microbial oxidation of nitrogen released by organic matter mineralization is a major source of soil acidity.

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

Nitrogen is a component of which essential plant compounds?

Ammonia losses from the shallow, algae-filled water of a non-tidal wetland are likely to be much greater at night than during the day.

Although slow release fertilizers take longer to have an effect, they are more economical than regular nitrogen fertilizers and so are favored by foresters and farmers.

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

Ammonium fixation would be expected to be greatest in soils containing a lot of______.

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

In the early stages of plant nitrogen deficiency, the most obvious symptoms are _____.

The terms "ammonium fixation" and "biological nitrogen fixation" refer to the same soil process.

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

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

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

Soil Colloids: Seat of Soil Chemical and Physical Activity

Soil Acidity

Soils of Dry Regions: Alkalinity, Salinity, and Sodicity

Organisms and Ecology of the Soil

Soil Organic Matter

Soil Phosphorus and Potassium

Micronutrients and Other Trace Elements

Practical Nutrient Management

Soil Erosion and Its Control

Soils and Chemical Pollution

Geographic Soils Information

Prospects for Global Soil Quality

Filters

Exam 13: Nitrogen and Sulfur Economy of Soils

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

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

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

Ammonium fixation occurs to the greatest extent in the O and A horizons.

Plants obtain nitrogen from the soil by taking up ______.

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

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

Soluble organic N compounds are taken up by plants and are lost in leaching and runoff waters.

The natural microbial oxidation of nitrogen released by organic matter mineralization is a major source of soil acidity.

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

Nitrogen is a component of which essential plant compounds?

Ammonia losses from the shallow, algae-filled water of a non-tidal wetland are likely to be much greater at night than during the day.

Although slow release fertilizers take longer to have an effect, they are more economical than regular nitrogen fertilizers and so are favored by foresters and farmers.

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

Ammonium fixation would be expected to be greatest in soils containing a lot of______.

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

In the early stages of plant nitrogen deficiency, the most obvious symptoms are _____.

The terms "ammonium fixation" and "biological nitrogen fixation" refer to the same soil process.

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

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

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

Soil Colloids: Seat of Soil Chemical and Physical Activity

Soil Acidity

Soils of Dry Regions: Alkalinity, Salinity, and Sodicity

Organisms and Ecology of the Soil

Soil Organic Matter

Soil Phosphorus and Potassium

Micronutrients and Other Trace Elements

Practical Nutrient Management

Soil Erosion and Its Control

Soils and Chemical Pollution

Geographic Soils Information

Prospects for Global Soil Quality

Filters