Question 1

Conservation tillage can help reduce salt build up by reducing surface evaporation.

Accepted Answer

A) True 
 B)False  True

Question 2

The source of salts for some naturally occurring saline soils are ancient fossil deposits of salts in old lake beds.

Accepted Answer

A) True 
 B)False  True

Question 3

Some irrigation systems have stimulated the formation of saline and saline-sodic soils. Which of the following contributes to this process?

Accepted Answer

A)  the low sodium adsorption ratio in the irrigation water 
B)  high Ca and Mg contents in the irrigation water 
C)  inadequate drainage systems to remove soluble salts 
D)  high contents of sulfates and chlorides in the irrigation water 
E)  low pH of the irrigation water 
A)  the low sodium adsorption ratio in the irrigation water 
B)  high Ca and Mg contents in the irrigation water 
C)  inadequate drainage systems to remove soluble salts 
D)  high contents of sulfates and chlorides in the irrigation water 
E)  low pH of the irrigation water C

Question 4

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

Accepted Answer

A) True 
 B)False

Question 5

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 6

Gypsum is the most widely used chemical for the reclamation of sodic soils. What characteristic likely accounts for this popularity?

Accepted Answer

A)  Gypsum is abundant and low priced. 
B)  Gypsum is quite insoluble so it remains in the soil for long periods of time. 
C)  Gypsum provides sulfates that attract Na+ from the exchange complex. 
D)  Gypsum forms sulfuric acid that helps reduce the soil pH. 
E)  Gypsum reacts with Na+ ions to form insoluble Na2SO4. 
A)  Gypsum is abundant and low priced. 
B)  Gypsum is quite insoluble so it remains in the soil for long periods of time. 
C)  Gypsum provides sulfates that attract Na+ from the exchange complex. 
D)  Gypsum forms sulfuric acid that helps reduce the soil pH. 
E)  Gypsum reacts with Na+ ions to form insoluble Na2SO4.

Question 7

Saline soils are characterized by _______.

Accepted Answer

A)  high CaCO3 levels near the soil surface 
B)  sodium adsorption ratios of 13 or higher 
C)  electrical conductivity of standard saturated paste of less than 4 dS/m 
D)  pH values of less than 8.5 
E)  low chloride and sulfate contents 
A)  high CaCO3 levels near the soil surface 
B)  sodium adsorption ratios of 13 or higher 
C)  electrical conductivity of standard saturated paste of less than 4 dS/m 
D)  pH values of less than 8.5 
E)  low chloride and sulfate contents

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

Soils with high sodium adsorption ratios commonly have very stable soil structures.

Accepted Answer

A) True 
 B)False

Question 10

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 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 soil 
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 soil

Question 12

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

Accepted Answer

A) True 
 B)False

Question 13

Normal alkaline soils often exhibit deficiencies of available iron and manganese.

Accepted Answer

A) True 
 B)False

Question 14

The cation exchange capacities of alkaline soils are generally higher than those of acid soils (Vertisols excepted). Which of the following characteristics of alkaline soils most likely accounts for this high CEC?

Accepted Answer

A)  high humus content 
B)  high content of hydrous oxides of iron and aluminum 
C)  high exchangeable calcium 
D)  high exchangeable sodium content 
E)  high content of 2:1 type clays 
A)  high humus content 
B)  high content of hydrous oxides of iron and aluminum 
C)  high exchangeable calcium 
D)  high exchangeable sodium content 
E)  high content of 2:1 type clays

Question 15

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 16

The electrical conductivity (EC) of a paste of a saline soil and water is generally less than 4 dS/m.

Accepted Answer

A) True 
 B)False

Question 17

Which of the following plants would be most apt to tolerate high soil salinity?

Accepted Answer

A)  cotton 
B)  alfalfa 
C)  apples 
D)  corn 
E)  tomato 
A)  cotton 
B)  alfalfa 
C)  apples 
D)  corn 
E)  tomato

Question 18

The cation exchange capacity of humus increases if pH increases.

Accepted Answer

A) True 
 B)False

Question 19

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

Question 20

Phosphate availability is constrained in alkaline soils by the presence of iron and aluminum oxides.

Accepted Answer

A) True 
 B)False

Conservation tillage can help reduce salt build up by reducing surface evaporation.

The source of salts for some naturally occurring saline soils are ancient fossil deposits of salts in old lake beds.

Some irrigation systems have stimulated the formation of saline and saline-sodic soils. Which of the following contributes to this process?

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

Gypsum is the most widely used chemical for the reclamation of sodic soils. What characteristic likely accounts for this popularity?

Saline soils are characterized by _______.

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

Soils with high sodium adsorption ratios commonly have very stable soil structures.

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?

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

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

Normal alkaline soils often exhibit deficiencies of available iron and manganese.

The cation exchange capacities of alkaline soils are generally higher than those of acid soils (Vertisols excepted). Which of the following characteristics of alkaline soils most likely accounts for this high CEC?

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.

The electrical conductivity (EC) of a paste of a saline soil and water is generally less than 4 dS/m.

Which of the following plants would be most apt to tolerate high soil salinity?

The cation exchange capacity of humus increases if pH increases.

Phosphate availability is constrained in alkaline soils by the presence of iron and aluminum oxides.

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

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Exam 9: Soil Acidity, Alkalinity, Aridity and Salinity

Conservation tillage can help reduce salt build up by reducing surface evaporation.

The source of salts for some naturally occurring saline soils are ancient fossil deposits of salts in old lake beds.

Some irrigation systems have stimulated the formation of saline and saline-sodic soils. Which of the following contributes to this process?

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

Gypsum is the most widely used chemical for the reclamation of sodic soils. What characteristic likely accounts for this popularity?

Saline soils are characterized by _______.

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

Soils with high sodium adsorption ratios commonly have very stable soil structures.

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?

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

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

Normal alkaline soils often exhibit deficiencies of available iron and manganese.

The cation exchange capacities of alkaline soils are generally higher than those of acid soils (Vertisols excepted). Which of the following characteristics of alkaline soils most likely accounts for this high CEC?

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.

The electrical conductivity (EC) of a paste of a saline soil and water is generally less than 4 dS/m.

Which of the following plants would be most apt to tolerate high soil salinity?

The cation exchange capacity of humus increases if pH increases.

Phosphate availability is constrained in alkaline soils by the presence of iron and aluminum oxides.

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