Question 1

Saline soils are characteristic of arid and semiarid areas with poor internal drainage.

Accepted Answer

A) True 
 B)False

Question 2

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

Accepted Answer

A) True 
 B)False

Question 3

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

Accepted Answer

A) True 
 B)False

Question 4

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 5

Lack of adequate drainage in irrigation projects leads to the accumulation of CaCO3 that is responsible for the high pH values above 8.5.

Accepted Answer

A) True 
 B)False

Question 6

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 7

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 8

Iron and manganese are commonly deficient in very acid soils.

Accepted Answer

A) True 
 B)False

Question 9

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 10

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

Accepted Answer

A) True 
 B)False

Question 11

Removal of excess salts from the soil profile is a requisite for the reclamation of a saline soil.

Accepted Answer

A) True 
 B)False

Question 12

The high pH of sodic soils is due to the high saturation of the colloidal complex with calcium.

Accepted Answer

A) True 
 B)False

Question 13

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

Question 14

Which of the following correctly describes the relationship among the several methods available to measure electrical conductivity (EC) of soils?

Accepted Answer

A)  The saturated paste extract method is the best field method. 
B)  The four electrode field sensor gives EC values about 2x those of the saturated paste method. 
C)  The saturation extract procedure is more accurate than the saturated paste method. 
D)  Electromagnetic induction method requires prongs to penetrate the soil. 
E)  The saturated paste method takes more time than the four electrode field sensor. 
A)  The saturated paste extract method is the best field method. 
B)  The four electrode field sensor gives EC values about 2x those of the saturated paste method. 
C)  The saturation extract procedure is more accurate than the saturated paste method. 
D)  Electromagnetic induction method requires prongs to penetrate the soil. 
E)  The saturated paste method takes more time than the four electrode field sensor.

Question 15

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

Accepted Answer

A) True 
 B)False

Question 16

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 17

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 18

Elemental sulfur is the most widely used chemical for the reclamation of sodic soils.

Accepted Answer

A) True 
 B)False

Question 19

The exchange complexes of strongly acid (pH 4.5) mineral soils are saturated mainly with _____.

Accepted Answer

A)  exchangeable H+ ions 
B)  exchangeable Al3+ ions 
C)  exchangeable Al(OH2)+ ions 
D)  tightly bound H+ ions 
E)  tightly bound Al3+ ions 
A)  exchangeable H+ ions 
B)  exchangeable Al3+ ions 
C)  exchangeable Al(OH2)+ ions 
D)  tightly bound H+ ions 
E)  tightly bound Al3+ ions

Question 20

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

Saline soils are characteristic of arid and semiarid areas with poor internal drainage.

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

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

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

Lack of adequate drainage in irrigation projects leads to the accumulation of CaCO₃ that is responsible for the high pH values above 8.5.

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

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

Iron and manganese are commonly deficient in very acid soils.

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

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

Removal of excess salts from the soil profile is a requisite for the reclamation of a saline soil.

The high pH of sodic soils is due to the high saturation of the colloidal complex with calcium.

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

Which of the following correctly describes the relationship among the several methods available to measure electrical conductivity (EC) of soils?

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

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?

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

Elemental sulfur is the most widely used chemical for the reclamation of sodic soils.

The exchange complexes of strongly acid (pH 4.5) mineral soils are saturated mainly with _____.

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 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

Organisms and Ecology of the Soil

Soil Organic Matter Overview

Nutrient Cycles and Soil Fertility

Practical Nutrient Management

Soil Erosion and Its Control

Soils and Chemical Pollution

Filters

Exam 9: Soil Acidity, Alkalinity, Aridity and Salinity

Saline soils are characteristic of arid and semiarid areas with poor internal drainage.

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

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

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

Lack of adequate drainage in irrigation projects leads to the accumulation of CaCO3 that is responsible for the high pH values above 8.5.

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

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

Iron and manganese are commonly deficient in very acid soils.

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

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

Removal of excess salts from the soil profile is a requisite for the reclamation of a saline soil.

The high pH of sodic soils is due to the high saturation of the colloidal complex with calcium.

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

Which of the following correctly describes the relationship among the several methods available to measure electrical conductivity (EC) of soils?

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

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?

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

Elemental sulfur is the most widely used chemical for the reclamation of sodic soils.

The exchange complexes of strongly acid (pH 4.5) mineral soils are saturated mainly with _____.

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 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

Organisms and Ecology of the Soil

Soil Organic Matter Overview

Nutrient Cycles and Soil Fertility

Practical Nutrient Management

Soil Erosion and Its Control

Soils and Chemical Pollution

Filters

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

Lack of adequate drainage in irrigation projects leads to the accumulation of CaCO₃ that is responsible for the high pH values above 8.5.