Question 1

Iron and manganese are commonly deficient in very acid soils.

Accepted Answer

A) True 
 B)False  False

Question 2

Assume you want to grow azaleas in a soil with a pH of 6.0.The application of which of the following would be most appropriate to make this soil suitable for this ornamental?

Accepted Answer

A) chicken manure 
B) limestone 
C) elemental sulfur 
D) iron oxide 
E) hydrated lime 
A) chicken manure 
B) limestone 
C) elemental sulfur 
D) iron oxide 
E) hydrated lime C

Question 3

Which of the following would likely grow best on a soil with a pH of 6.0?

Accepted Answer

A) alfalfa 
B) sweet clover 
C) tomatoes 
D) blueberries 
E) cranberries 
A) alfalfa 
B) sweet clover 
C) tomatoes 
D) blueberries 
E) cranberries C

Question 4

Among the soils of which order would you most likely find the highest buffering capacities?

Accepted Answer

A) Alfisols 
B) Vertisols 
C) Oxisols 
D) Spodosols 
E) Ultisols 
A) Alfisols 
B) Vertisols 
C) Oxisols 
D) Spodosols 
E) Ultisols

Question 5

Which of the following trees would you expect to fare most poorly in a soil at pH 5.0?

Accepted Answer

A) loblolly pine 
B) aspen 
C) sumac 
D) walnut 
E) white spruce 
A) loblolly pine 
B) aspen 
C) sumac 
D) walnut 
E) white spruce

Question 6

In extremely acid soils (pH 3.0 to 4.0) most of the Al3+ and H+ ions are bound tightly by organic matter and silicate clays and are not readily exchangeable.

Accepted Answer

A) True 
 B)False

Question 7

A soil has a maximum potential cation exchange capacity of 30 cmolc/kg and has a 50% acid saturation.If you want to decrease the percentage acid saturation to 10%, how many cmolc of calcium would it take to replace the exchangeable acid cations per kg of soil? Assume all the calcium exchanged with aluminum.

Accepted Answer

A) 30 
B) 40 
C) 6 
D) 12 
E) 5 
A) 30 
B) 40 
C) 6 
D) 12 
E) 5

Question 8

Phosphorus availability in acid soils is constrained by the presence of significant quantities of reactive ______.

Accepted Answer

A) iron 
B) calcium 
C) magnesium 
D) sulfur 
E) boron. 
A) iron 
B) calcium 
C) magnesium 
D) sulfur 
E) boron.

Question 9

Active soil acidity is a measure of the H+ ion activity in the soil solution.

Accepted Answer

A) True 
 B)False

Question 10

The higher the cation exchange capacity of a soil, the greater is its buffer capacity.

Accepted Answer

A) True 
 B)False

Question 11

Which of the following human actions is most apt to result in a long term increase in soil pH?

Accepted Answer

A) application of NH4- containing fertilizers 
B) application of farm manure 
C) irrigation with high sodium salt-containing waters 
D) emission of gases from automobiles 
E) application of unlimed sewage sludge 
A) application of NH4- containing fertilizers 
B) application of farm manure 
C) irrigation with high sodium salt-containing waters 
D) emission of gases from automobiles 
E) application of unlimed sewage sludge

Question 12

The amount of exchangeable acidity is much smaller than the residual acidity.

Accepted Answer

A) True 
 B)False

Question 13

Nitrogen fertilization is a significant cause of acidity in many cultivated soils.

Accepted Answer

A) True 
 B)False

Question 14

How does the amount of lime needed to neutralize the residual acidity in a clay loam soil compare to that needed to neutralize the active acidity in that soil?

Accepted Answer

A) residual requires considerably less 
B) residual requires about the same 
C) residual requires about double 
D) residual requires 10 times greater 
E) residual requires 5,000 times greater 
A) residual requires considerably less 
B) residual requires about the same 
C) residual requires about double 
D) residual requires 10 times greater 
E) residual requires 5,000 times greater

Question 15

If you want to grow azaleas in a soil that initially has a pH of 6.5 and have been told that you should apply sulfur to reduce the soil pH, you would likely need more sulfur if the soil is a clay Vertisol than if it is an clay Ultisol.

Accepted Answer

A) True 
 B)False

Question 16

The drainage of some coastal wetland soils results in high pH due to underlying lime deposits.

Accepted Answer

A) True 
 B)False

Question 17

An acid soil is known to contain toxic quantities of a certain plant nutrient.Which of these essential elements is it most likely to be?

Accepted Answer

A) nitrogen 
B) manganese 
C) phosphorus 
D) molybdenum 
E) boron 
A) nitrogen 
B) manganese 
C) phosphorus 
D) molybdenum 
E) boron

Question 18

In humid regions repeat applications of limestone are needed after a few years primarily because of ____.

Accepted Answer

A) the release of aluminum ions from the structure of silicate clays 
B) the annual loss of calcium and magnesium in drainage waters 
C) increases in soil acidity from acid rain 
D) increased rates of formation of carbonic acid (H2CO3) 
E) increases in phosphate fertilization 
A) the release of aluminum ions from the structure of silicate clays 
B) the annual loss of calcium and magnesium in drainage waters 
C) increases in soil acidity from acid rain 
D) increased rates of formation of carbonic acid (H2CO3) 
E) increases in phosphate fertilization

Question 19

Soil reaction indicates the degree of acidity or alkalinity in a soil.

Accepted Answer

A) True 
 B)False

Question 20

The ill effects of acidity in subsoils can be ameliorated by adding gypsum (CaSO4-2H2O) to the soil surface.Which of the following most likely helps account for this effect?

Accepted Answer

A) The gypsum replaces hydrogen from colloids which moves down the profile and decreases the pH of the subsoil layers. 
B) Calcium from the gypsum replaces hydrogen from colloids in the subsoil thereby increasing the soil pH. 
C) Gypsum dissolves and leaches downward, increasing the Ca/Al ratio in the soil solution in subsoil layers. 
D) Sulfate ions from the gypsum react with H ions in the subsoil to form H2SO4. 
E) Gypsum stimulates root growth in the surface soil horizons. 
A) The gypsum replaces hydrogen from colloids which moves down the profile and decreases the pH of the subsoil layers. 
B) Calcium from the gypsum replaces hydrogen from colloids in the subsoil thereby increasing the soil pH. 
C) Gypsum dissolves and leaches downward, increasing the Ca/Al ratio in the soil solution in subsoil layers. 
D) Sulfate ions from the gypsum react with H ions in the subsoil to form H2SO4. 
E) Gypsum stimulates root growth in the surface soil horizons.

Iron and manganese are commonly deficient in very acid soils.

Assume you want to grow azaleas in a soil with a pH of 6.0.The application of which of the following would be most appropriate to make this soil suitable for this ornamental?

Which of the following would likely grow best on a soil with a pH of 6.0?

Among the soils of which order would you most likely find the highest buffering capacities?

Which of the following trees would you expect to fare most poorly in a soil at pH 5.0?

In extremely acid soils (pH 3.0 to 4.0) most of the Al³⁺ and H⁺ ions are bound tightly by organic matter and silicate clays and are not readily exchangeable.

Phosphorus availability in acid soils is constrained by the presence of significant quantities of reactive ______.

Active soil acidity is a measure of the H⁺ ion activity in the soil solution.

The higher the cation exchange capacity of a soil, the greater is its buffer capacity.

Which of the following human actions is most apt to result in a long term increase in soil pH?

The amount of exchangeable acidity is much smaller than the residual acidity.

Nitrogen fertilization is a significant cause of acidity in many cultivated soils.

How does the amount of lime needed to neutralize the residual acidity in a clay loam soil compare to that needed to neutralize the active acidity in that soil?

If you want to grow azaleas in a soil that initially has a pH of 6.5 and have been told that you should apply sulfur to reduce the soil pH, you would likely need more sulfur if the soil is a clay Vertisol than if it is an clay Ultisol.

The drainage of some coastal wetland soils results in high pH due to underlying lime deposits.

An acid soil is known to contain toxic quantities of a certain plant nutrient.Which of these essential elements is it most likely to be?

In humid regions repeat applications of limestone are needed after a few years primarily because of ____.

Soil reaction indicates the degree of acidity or alkalinity in a soil.

The ill effects of acidity in subsoils can be ameliorated by adding gypsum (CaSO₄^-2H₂O) to the soil surface.Which of the following most likely helps account for this effect?

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

Soils of Dry Regions: Alkalinity, Salinity, and Sodicity

Organisms and Ecology of the Soil

Soil Organic Matter

Nitrogen and Sulfur Economy of Soils

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 9: Soil Acidity

Iron and manganese are commonly deficient in very acid soils.

Assume you want to grow azaleas in a soil with a pH of 6.0.The application of which of the following would be most appropriate to make this soil suitable for this ornamental?

Which of the following would likely grow best on a soil with a pH of 6.0?

Among the soils of which order would you most likely find the highest buffering capacities?

Which of the following trees would you expect to fare most poorly in a soil at pH 5.0?

In extremely acid soils (pH 3.0 to 4.0) most of the Al3+ and H+ ions are bound tightly by organic matter and silicate clays and are not readily exchangeable.

Phosphorus availability in acid soils is constrained by the presence of significant quantities of reactive ______.

Active soil acidity is a measure of the H+ ion activity in the soil solution.

The higher the cation exchange capacity of a soil, the greater is its buffer capacity.

Which of the following human actions is most apt to result in a long term increase in soil pH?

The amount of exchangeable acidity is much smaller than the residual acidity.

Nitrogen fertilization is a significant cause of acidity in many cultivated soils.

How does the amount of lime needed to neutralize the residual acidity in a clay loam soil compare to that needed to neutralize the active acidity in that soil?

If you want to grow azaleas in a soil that initially has a pH of 6.5 and have been told that you should apply sulfur to reduce the soil pH, you would likely need more sulfur if the soil is a clay Vertisol than if it is an clay Ultisol.

The drainage of some coastal wetland soils results in high pH due to underlying lime deposits.

An acid soil is known to contain toxic quantities of a certain plant nutrient.Which of these essential elements is it most likely to be?

In humid regions repeat applications of limestone are needed after a few years primarily because of ____.

Soil reaction indicates the degree of acidity or alkalinity in a soil.

The ill effects of acidity in subsoils can be ameliorated by adding gypsum (CaSO4-2H2O) to the soil surface.Which of the following most likely helps account for this effect?

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

Soils of Dry Regions: Alkalinity, Salinity, and Sodicity

Organisms and Ecology of the Soil

Soil Organic Matter

Nitrogen and Sulfur Economy of Soils

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

In extremely acid soils (pH 3.0 to 4.0) most of the Al³⁺ and H⁺ ions are bound tightly by organic matter and silicate clays and are not readily exchangeable.

Active soil acidity is a measure of the H⁺ ion activity in the soil solution.

The ill effects of acidity in subsoils can be ameliorated by adding gypsum (CaSO₄^-2H₂O) to the soil surface.Which of the following most likely helps account for this effect?