Question 1

Sodic soils are sometimes referred to as white alkalis because of the white salt crusts that appear on the surface.

Accepted Answer

A) True 
 B)False  False

Question 2

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 D

Question 3

Attempts to leach the excess salts from a saline-sodic soil resulted in a marked reduction of crop yields.To what is this most likely due?

Accepted Answer

A) deficiency of iron and manganese 
B) increase in percentage sodium saturation 
C) removal of Ca2+ and Mg2+ ions from the exchange complex 
D) increase in the soil pH 
E) increase in the Al3+ concentration 
A) deficiency of iron and manganese 
B) increase in percentage sodium saturation 
C) removal of Ca2+ and Mg2+ ions from the exchange complex 
D) increase in the soil pH 
E) increase in the Al3+ concentration B

Question 4

Saline-sodic soils have electrical conductivities greater than 4 dS/m and a sodium adsorption ratio of less than 13.

Accepted Answer

A) True 
 B)False

Question 5

Sodic soils generally have a poor physical condition.To what is this most likely due?

Accepted Answer

A) low organic matter content 
B) impact of raindrops on the soil surface 
C) dispersal of the Na saturated soil colloids 
D) precipitation of the Ca2+ and Mg2+ ions as carbonates 
E) high content of smectite in the soils 
A) low organic matter content 
B) impact of raindrops on the soil surface 
C) dispersal of the Na saturated soil colloids 
D) precipitation of the Ca2+ and Mg2+ ions as carbonates 
E) high content of smectite in the soils

Question 6

Available phosphorus levels are constrained in alkaline and salt-affected soils because of _____.

Accepted Answer

A) high iron and aluminum levels 
B) high exchangeable sodium levels 
C) high calcium and magnesium levels 
D) high manganese levels 
E) low hydrogen ion levels 
A) high iron and aluminum levels 
B) high exchangeable sodium levels 
C) high calcium and magnesium levels 
D) high manganese levels 
E) low hydrogen ion levels

Question 7

Normal alkaline soils are characterized by all but which one of the following?

Accepted Answer

A) low levels of available iron 
B) high levels of molybdenum 
C) high levels of exchangeable sodium 
D) low levels of available manganese 
E) low levels of available boron 
A) low levels of available iron 
B) high levels of molybdenum 
C) high levels of exchangeable sodium 
D) low levels of available manganese 
E) low levels of available boron

Question 8

If you want to reclaim a saline soil, which of the following practices would you most likely use?

Accepted Answer

A) Add CaCO3 to reduce the exchangeable Na+ level. 
B) Leach the soil with low salt containing water. 
C) Leach the soil with water having a high SAR ratio. 
D) Leach the soil with water high in Ca2+ and Mg2+. 
E) Leach the soil with water high in bicarbonates. 
A) Add CaCO3 to reduce the exchangeable Na+ level. 
B) Leach the soil with low salt containing water. 
C) Leach the soil with water having a high SAR ratio. 
D) Leach the soil with water high in Ca2+ and Mg2+. 
E) Leach the soil with water high in bicarbonates.

Question 9

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 10

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

Accepted Answer

A) True 
 B)False

Question 11

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

Accepted Answer

A) True 
 B)False

Question 12

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

Accepted Answer

A) True 
 B)False

Question 13

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

Accepted Answer

A) True 
 B)False

Question 14

Irrigation of a saline-sodic soil with water very low in salts could lead to the formation of a sodic soil.

Accepted Answer

A) True 
 B)False

Question 15

A farmer started irrigating a soil some 10 years ago but in recent years yields have declined and the soil physical condition has deteriorated.Which of the following most likely accounts for this situation?

Accepted Answer

A) high content of Ca and Mg in the irrigation water 
B) failure to use conservation tillage to reduce salt accumulation at the soil surface 
C) high SAR of the irrigation water 
D) excessive drainage of the soil 
E) high gypsum content in the soil 
A) high content of Ca and Mg in the irrigation water 
B) failure to use conservation tillage to reduce salt accumulation at the soil surface 
C) high SAR of the irrigation water 
D) excessive drainage of the soil 
E) high gypsum content in the soil

Question 16

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

Question 17

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 18

You were advised to use elemental sulfur in the reclamation of a saline-sodic soil.Indicate how the sulfur helps bring about this reclamation.

Accepted Answer

A) Sulfur leaches down into the soil and increases the soil pH. 
B) Sulfur is oxidized to sulfates that will precipitate much of the exchangeable Na+. 
C) Sulfur helps maintain high salt content while reducing exchangeable Na+ levels. 
D) Sulfur is oxidized and forms sulfuric acid which, in turn, removes the exchangeable Na+. 
E) Sulfur stimulates the formation of gypsum in the soil. 
A) Sulfur leaches down into the soil and increases the soil pH. 
B) Sulfur is oxidized to sulfates that will precipitate much of the exchangeable Na+. 
C) Sulfur helps maintain high salt content while reducing exchangeable Na+ levels. 
D) Sulfur is oxidized and forms sulfuric acid which, in turn, removes the exchangeable Na+. 
E) Sulfur stimulates the formation of gypsum in the soil.

Question 19

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 20

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

Sodic soils are sometimes referred to as white alkalis because of the white salt crusts that appear on the surface.

Saline soils are characterized by _______.

Attempts to leach the excess salts from a saline-sodic soil resulted in a marked reduction of crop yields.To what is this most likely due?

Saline-sodic soils have electrical conductivities greater than 4 dS/m and a sodium adsorption ratio of less than 13.

Sodic soils generally have a poor physical condition.To what is this most likely due?

Available phosphorus levels are constrained in alkaline and salt-affected soils because of _____.

Normal alkaline soils are characterized by all but which one of the following?

If you want to reclaim a saline soil, which of the following practices would you most likely use?

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

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

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

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

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

Irrigation of a saline-sodic soil with water very low in salts could lead to the formation of a sodic soil.

A farmer started irrigating a soil some 10 years ago but in recent years yields have declined and the soil physical condition has deteriorated.Which of the following most likely accounts for this situation?

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

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

You were advised to use elemental sulfur in the reclamation of a saline-sodic soil.Indicate how the sulfur helps bring about this reclamation.

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

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

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

Soil Acidity

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 10: Soils of Dry Regions: Alkalinity, Salinity, and Sodicity

Sodic soils are sometimes referred to as white alkalis because of the white salt crusts that appear on the surface.

Saline soils are characterized by _______.

Attempts to leach the excess salts from a saline-sodic soil resulted in a marked reduction of crop yields.To what is this most likely due?

Saline-sodic soils have electrical conductivities greater than 4 dS/m and a sodium adsorption ratio of less than 13.

Sodic soils generally have a poor physical condition.To what is this most likely due?

Available phosphorus levels are constrained in alkaline and salt-affected soils because of _____.

Normal alkaline soils are characterized by all but which one of the following?

If you want to reclaim a saline soil, which of the following practices would you most likely use?

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

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

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

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

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

Irrigation of a saline-sodic soil with water very low in salts could lead to the formation of a sodic soil.

A farmer started irrigating a soil some 10 years ago but in recent years yields have declined and the soil physical condition has deteriorated.Which of the following most likely accounts for this situation?

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

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

You were advised to use elemental sulfur in the reclamation of a saline-sodic soil.Indicate how the sulfur helps bring about this reclamation.

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

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

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

Soil Acidity

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