Question 1

Poor plant growth in a well-drained irrigated soil in an arid region (pH=8.0)is most likely due to ________.

Accepted Answer

A) manganese toxicity 
B) iron deficiency 
C) phosphate toxicity 
D) calcium toxicity 
E) molybdenum deficiency 
A) manganese toxicity 
B) iron deficiency 
C) phosphate toxicity 
D) calcium toxicity 
E) molybdenum deficiency

Question 2

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 3

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 4

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

Accepted Answer

A) True 
 B)False

Question 5

Which of the following would occur when lime is added to the surface of a soil at pH 6.0?

Accepted Answer

A) Earthworms would help move the limestone down into the soil profile. 
B) Conservation tillage would increase the pH of the subsoil. 
C) CO2 from root and microbial respiration would quickly solubilize the CaCO3 and increase its rate of downward movement. 
D) Aluminum toxicity would increase in the vicinity of the limestone. 
E) The release of H+ ions from the exchange complex would help reduce the soil pH. 
A) Earthworms would help move the limestone down into the soil profile. 
B) Conservation tillage would increase the pH of the subsoil. 
C) CO2 from root and microbial respiration would quickly solubilize the CaCO3 and increase its rate of downward movement. 
D) Aluminum toxicity would increase in the vicinity of the limestone. 
E) The release of H+ ions from the exchange complex would help reduce the soil pH.

Question 6

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 7

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

Accepted Answer

A) True 
 B)False

Question 8

If you want to quickly (in just a few days)increase the pH of a soil from 5.5 to 7.0,which of the following would you use?

Accepted Answer

A) sawdust 
B) calcitic limestone 
C) dolomitic limestone 
D) burned lime 
E) ammonium nitrate 
A) sawdust 
B) calcitic limestone 
C) dolomitic limestone 
D) burned lime 
E) ammonium nitrate

Question 9

The acidity of "acid rain" can be traced to the reaction of CO2 in the atmosphere forming carbonic acid (H2CO3).

Accepted Answer

A) True 
 B)False

Question 10

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

Accepted Answer

A) True 
 B)False

Question 11

The very high pH levels found in some arid region soils are most likely due to high levels of exchangeable _____.

Accepted Answer

A) Al3+ 
B) Al(OH)2+ 
C) Ca2+ 
D) Mg2+ 
E) Na+ 
A) Al3+ 
B) Al(OH)2+ 
C) Ca2+ 
D) Mg2+ 
E) Na+

Question 12

Hydrogen ions dominate the exchange complex of very acid soils (pH<5).

Accepted Answer

A) True 
 B)False

Question 13

Sulfur can be used to increase soil acidity and to reduce alkalinity.

Accepted Answer

A) True 
 B)False

Question 14

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.

Question 15

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

Question 16

Bright brownish or reddish colored soil or saprolite layers encountered during excavation are likely to be result in acid sulfate soil problems if exposed to the air.

Accepted Answer

A) True 
 B)False

Question 17

Loblolly pine tolerates higher levels of acidity than beech or maple trees.

Accepted Answer

A) True 
 B)False

Question 18

The presence of neutral salts in an alkaline soil has a tendency to increase the pH of the soil.

Accepted Answer

A) True 
 B)False

Question 19

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 a clay Ultisol.

Accepted Answer

A) True 
 B)False

Question 20

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.

Poor plant growth in a well-drained irrigated soil in an arid region (pH=8.0)is most likely due to ________.

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

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?

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

Which of the following would occur when lime is added to the surface of a soil at pH 6.0?

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

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

If you want to quickly (in just a few days)increase the pH of a soil from 5.5 to 7.0,which of the following would you use?

The acidity of "acid rain" can be traced to the reaction of CO₂ in the atmosphere forming carbonic acid (H₂CO₃).

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

The very high pH levels found in some arid region soils are most likely due to high levels of exchangeable _____.

Hydrogen ions dominate the exchange complex of very acid soils (pH<5).

Sulfur can be used to increase soil acidity and to reduce alkalinity.

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?

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?

Bright brownish or reddish colored soil or saprolite layers encountered during excavation are likely to be result in acid sulfate soil problems if exposed to the air.

Loblolly pine tolerates higher levels of acidity than beech or maple trees.

The presence of neutral salts in an alkaline soil has a tendency to increase the pH of the 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 a clay Ultisol.

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

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

Soils of Dry Regionsalkalinity,salinity and Sodicity

Organisms and Ecology of the Soil

Soil Organic Matter

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 9: Soil Acidity

Poor plant growth in a well-drained irrigated soil in an arid region (pH=8.0)is most likely due to ________.

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

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?

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

Which of the following would occur when lime is added to the surface of a soil at pH 6.0?

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

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

If you want to quickly (in just a few days)increase the pH of a soil from 5.5 to 7.0,which of the following would you use?

The acidity of "acid rain" can be traced to the reaction of CO2 in the atmosphere forming carbonic acid (H2CO3).

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

The very high pH levels found in some arid region soils are most likely due to high levels of exchangeable _____.

Hydrogen ions dominate the exchange complex of very acid soils (pH<5).

Sulfur can be used to increase soil acidity and to reduce alkalinity.

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?

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?

Bright brownish or reddish colored soil or saprolite layers encountered during excavation are likely to be result in acid sulfate soil problems if exposed to the air.

Loblolly pine tolerates higher levels of acidity than beech or maple trees.

The presence of neutral salts in an alkaline soil has a tendency to increase the pH of the 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 a clay Ultisol.

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

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

Soils of Dry Regionsalkalinity,salinity and Sodicity

Organisms and Ecology of the Soil

Soil Organic Matter

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

The acidity of "acid rain" can be traced to the reaction of CO₂ in the atmosphere forming carbonic acid (H₂CO₃).

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?