Question 1

Which of the following does not describe aluminum hydroxy ions (such as Al(OH) 2+)  in the soil?

Accepted Answer

A)  They are more prominent in acid than in neutral soils.
B)  They affect the pH of the soil solution through hydrolysis.
C)  They block negative sites on some clays thereby reducing the cation exchange capacity.
D)  They influence the swelling of some clays by entering into the interlayer spaces.
E)  They are commonly applied to help reduce the soil pH for acid-loving plants.F) B) and D)
G) B) and E)

Question 2

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.F) C) and D)
G) D) and E)

Question 3

The cation exchange capacity of humus increases if pH increases.

Accepted Answer

A) True 
 B)False

Question 4

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 5

The amount of limestone required to increase the pH from 5 to 7 would likely be higher for an Oxisol than for an Alfisol.

Accepted Answer

A) True 
 B)False

Question 6

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 7

Fungi are much more sensitive to strong acid conditions than are bacteria or actinomycetes.

Accepted Answer

A) True 
 B)False

Question 8

When the soil pH = 5.3, manganese is more likely than aluminum to be toxic to plants.

Accepted Answer

A) True 
 B)False

Question 9

You are using pure limestone (CaCO3)  to provide the calcium needed to exchange with acid cations in a soil with a maximum potential cation exchange capacity of 20 cmolc/kg.How many kg of this limestone would you need to add to a hectare furrow slice (2.0 x 106 kg)  to reduce the percentage acid saturation from 40 to 10%, assuming that all the calcium added exchanged with aluminum or hydrogen ions?

Accepted Answer

A)  20,000
B)  50,000
C)  12,000
D)  6,000
E)  8,000F) D) and E)
G) A) and B)

Question 10

If you wanted to quickly increase the pH of a soil to 7.5 to combat a disease in cabbages you are about to plant you should use hydrated lime rather than ground limestone.

Accepted Answer

A) True 
 B)False

Question 11

Under which of the following conditions would you favor a finely ground dolomitic limestone as your choice of a liming material?

Accepted Answer

A)  need for a rapid reaction with the soil
B)  need to provide magnesium in addition to calcium
C)  need for a material with a low shipping cost
D)  need to obtain a high soil pH
E)  need to significantly reduce the exchangeable Al3+ level in the soilF) C) and D)
G) D) and E)

Question 12

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 13

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 deficiencyF) A) and B)
G) A) and C)

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

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 nitrateF) A) and D)
G) A) and E)

Question 16

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

Accepted Answer

A) True 
 B)False

Question 17

Residual soil acidity is that acidity remaining in the soil after limestone has been applied.

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

A) True 
 B)False

Question 19

The buildup of excess salts in irrigated soils can result in increased pH if the salts are high in sodium bicarbonate.

Accepted Answer

A) True 
 B)False

Question 20

The drainage of certain wetlands has resulted in extreme soil acidity.This is due primarily to which of the following processes that take place when the soil is drained?

Accepted Answer

A)  oxidation of organic materials to produce organic acids
B)  reduction of iron to low valent states that stimulate acidity
C)  release of nitric acid due to oxidation of nitrogen compounds
D)  high redox potential characteristic of aerated soils
E)  oxidation of sulfur-bearing minerals that produces sulfuric acidF) C) and E)
G) C) and D)

Exam 9: Soil Acidity

The cation exchange capacity of humus increases if pH increases.

Correct Answer
verified

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

Correct Answer
verified

The amount of limestone required to increase the pH from 5 to 7 would likely be higher for an Oxisol than for an Alfisol.

Correct Answer
verified

Residual soil acidity is that acidity remaining in the soil after limestone has been applied.

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

The buildup of excess salts in irrigated soils can result in increased pH if the salts are high in sodium bicarbonate.

Correct Answer
verified

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

Correct Answer
verified

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.

Correct Answer
verified

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

Correct Answer
verified

Which of the following does not describe aluminum hydroxy ions (such as Al(OH) ₂⁺) in the soil?

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

When the soil pH = 5.3, manganese is more likely than aluminum to be toxic to plants.

Correct Answer
verified

Under which of the following conditions would you favor a finely ground dolomitic limestone as your choice of a liming material?

Correct Answer
verified

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?

Correct Answer
verified

If you wanted to quickly increase the pH of a soil to 7.5 to combat a disease in cabbages you are about to plant you should use hydrated lime rather than ground limestone.

Correct Answer
verified

Fungi are much more sensitive to strong acid conditions than are bacteria or actinomycetes.

Correct Answer
verified

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

Correct Answer
verified

The drainage of certain wetlands has resulted in extreme soil acidity.This is due primarily to which of the following processes that take place when the soil is drained?

Correct Answer
verified

Exam 9: Soil Acidity

The cation exchange capacity of humus increases if pH increases.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The amount of limestone required to increase the pH from 5 to 7 would likely be higher for an Oxisol than for an Alfisol.

Correct AnswerverifiedShow Answer

Residual soil acidity is that acidity remaining in the soil after limestone has been applied.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The buildup of excess salts in irrigated soils can result in increased pH if the salts are high in sodium bicarbonate.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following does not describe aluminum hydroxy ions (such as Al(OH) 2+) in the soil?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

When the soil pH = 5.3, manganese is more likely than aluminum to be toxic to plants.

Correct AnswerverifiedShow Answer

Under which of the following conditions would you favor a finely ground dolomitic limestone as your choice of a liming material?

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

If you wanted to quickly increase the pH of a soil to 7.5 to combat a disease in cabbages you are about to plant you should use hydrated lime rather than ground limestone.

Correct AnswerverifiedShow Answer

Fungi are much more sensitive to strong acid conditions than are bacteria or actinomycetes.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The drainage of certain wetlands has resulted in extreme soil acidity.This is due primarily to which of the following processes that take place when the soil is drained?

Correct AnswerverifiedShow Answer

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Which of the following does not describe aluminum hydroxy ions (such as Al(OH) ₂⁺) in the soil?

Correct Answer
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