Question 1

Most (usually 80% or more)of soil potassium and calcium can be found in the form of _________________.
A)dissolved substances
B)structural components of minerals
C)exchangeable ions
D)organic compounds

Accepted Answer

The majority of soil potassium and calcium are found in the form of structural components of minerals, such as feldspar and calcite. Dissolved substances and exchangeable ions make up a smaller portion, while organic compounds are typically a minor source of these nutrients in soil.

Question 2

Compared to silt,clay-sized soil particles are characterized by ______.
A)greater attraction for water
B)greater proportion of primary minerals
C)less tendency to form hard clods when dry
D)less capacity to hold nutrients in plant-available forms

Accepted Answer

Clay-sized soil particles have a greater surface area, which makes them capable of attracting and holding onto more water than silt-sized soil particles. This is because clay particles have more negatively charged sites on their surfaces, which attract positively charged water molecules.

Question 3

Hydroxyl ion concentrations are greatest in a soil solution with a pH value of ______.
A)0.1
B)4.0
C)5.0
D)6.5

Accepted Answer

The pH scale is a measure of the acidity or alkalinity of a solution, with lower values being more acidic and higher values being more alkaline. A pH of 7 is neutral. Hydroxyl ions (OH-) are more prevalent in alkaline conditions. Therefore, among the given options, a pH value of 6.5, being closest to neutral and less acidic than the others, would have the greatest concentration of hydroxyl ions.

Question 4

A soil profile consists of _________.
A)the sum of chemical and physical data known about a soil
B)the way a soil "feels"
C)the spatial boundaries of a particular soil
D)the set of layers seen in a vertical cross section of a soil
E)the general outline of a soil or group of soils when viewed from the side

Accepted Answer

A soil profile is the set of layers seen in a vertical cross section of a soil. These layers, or horizons, are formed by the accumulation and transformation of soil materials and the biotic and abiotic processes that occur within them. Each horizon has distinctive characteristics and properties that reflect the environmental conditions, the biological activity, and the physical and chemical interactions that have occurred over time. The soil profile is an important resource for scientists, land managers, and farmers because it provides information about the fertility, structure, drainage, and potential uses of a soil. By studying the soil profile, we can better understand how soils function and how to manage them sustainably.

Question 5

The lithosphere is made up of _________.
A)air
B)rock
C)water
D)plants and animals
E)all of the above

Accepted Answer

The lithosphere is the solid outermost shell of Earth, consisting of rocks, minerals, and soils.

Question 6

Which of the following is (are)essential plant nutrients?
A)Cu
B)Al
C)Sr
D)Pb
E)all of the above

Accepted Answer

Copper (Cu) is an essential plant nutrient, required for various physiological functions in plants, including photosynthesis, enzyme activation, and metabolism.

Question 7

Which of the following pH values represents a neutral condition?
A)1.0
B)5.0
C)6.0
D)7.0
E)10

Accepted Answer

A pH of 7.0 is neutral because it is the pH of pure water, which is neither acidic nor basic. pH values below 7.0 are acidic and pH values above 7.0 are basic.

Question 8

The amount of different sizes of mineral particles in a soil defines the soil ________.
A)structure
B)texture
C)pore space
D)solution
E)profile

Accepted Answer

The texture of soil is defined by the different sizes of mineral particles present in it. Soil structure refers to how these particles are arranged in the soil, pore space refers to the space between these particles that allows for water and air movement, solution refers to the dissolved minerals and organic matter in the soil, and profile refers to the vertical sequence of layers in a soil.

Question 9

Most of the different nutrients essential for growth are supplied to plants directly from the ______.
A)rain water
B)soil solution
C)atmosphere
D)cosmic radiation
E)humus

Accepted Answer

The answer of Most of the different nutrients essential for...

Question 10

Which of the following is considered to be a plant macronutrient?
A)N
B)P
C)S
D)Ca
E)all of the above

Accepted Answer

All of the listed elements (N, P, S, Ca) are considered to be plant macronutrients.

Question 11

In a load of 10 cubic meters of topsoil,approximately how many cubic meters of the volume would be solid material?
A)1
B)2.5
C)4
D)5
E)7.5

Accepted Answer

The solid material in topsoil typically makes up about 50% of the volume, so 10 cubic meters of topsoil would contain approximately 5 cubic meters of solid material.

Question 12

Which of the following pH values represents the most acid condition?
A)1.0
B)10.0
C)7.0
D)100
E)5.55

Accepted Answer

pH values range from 0 to 14, with 0 being the most acidic and 14 being the most basic. A pH of 1.0 indicates a high concentration of hydrogen ions (H+) in solution, making it the most acidic condition.

Question 13

Soil occupies the ______part of the regolith.
A)upper
B)lower
C)younger
D)both B and C

Accepted Answer

Soil is the uppermost layer of the regolith, which is made up of broken rock and minerals, organic matter, water, and air. Therefore, the correct choice is A.

Question 14

The water in the soil typically differs from pure water because the soil water ________.
A)contains organic compounds
B)contains mineral nutrients
C)is restrained in its flow by attraction to particle surfaces
D)all of the above
E)none of the above

Accepted Answer

The water in the soil can contain organic compounds and mineral nutrients that are dissolved or suspended in it, and its flow can be restrained by the attraction to particle surfaces. Therefore, all of the above options are correct.

Question 15

In a given soil,the horizon with the highest organic matter content is generally the _____ horizon.
A)E
B)C
C)D
D)B
E)A

Accepted Answer

The A horizon, often referred to as the topsoil, typically has the highest organic matter content due to the accumulation of decomposed plant and animal material.

Question 16

"Topsoil" is generally equivalent to which soil horizon?
A)A
B)B
C)C
D)D
E)E

Accepted Answer

Topsoil is the uppermost layer of soil, usually ranging in depth from 2-8 inches, where the majority of plant roots and microorganisms are found. It is generally equivalent to the A soil horizon, which is characterized by high organic matter content and significant biological activity.

Question 17

Increasing the organic matter content of a soil is likely to _____.
A)have no effect on water holding capacity
B)increase the soil's water holding capacity
C)decrease the soil's water holding capacity

Accepted Answer

Organic matter has a high capacity to hold water, so increasing the amount of organic matter in soil would increase the soil's water holding capacity.

Question 18

The layers of contrasting material found when one digs a hole in the ground are called _______.
A)pseudoliths
B)regoliths
C)pedons
D)horizons
E)soil structure

Accepted Answer

The layers of contrasting material found when one digs a hole in the ground are called horizons. The layers are created by the accumulation of different materials over time, such as organic matter, minerals, and sediment, and they can provide information about the soil's characteristics and history. Pseudoliths are false rocks, regoliths are the layer of loose material on top of solid rock, pedons are the basic unit of soil classification, and soil structure refers to the arrangement of soil particles.

Question 19

"Subsoil" is generally equivalent to which soil horizon?
A)A
B)B
C)C
D)D
E)E

Accepted Answer

The subsoil layer is generally equivalent to the B horizon, which is located beneath the topsoil (A horizon).

Question 20

In a typical mineral soil in optimal condition for plant growth,approximately what percentage of the pore space would be filled with water and what percentage filled with air?
A)10% water and 90% air
B)90% water and 10% air
C)25% water and 25% air
D)50% water and 50% air
E)25% water and 75% air

Accepted Answer

In a typical mineral soil in optimal condition for plant growth, approximately 50% of the pore space would be filled with water and 50% filled with air. This balance allows for proper water and oxygen uptake by plant roots.

Quiz 1: The Soils Around Us

Most (usually 80% or more) of soil potassium and calcium can be found in the form of _________________.

Compared to silt,clay-sized soil particles are characterized by ______.

Hydroxyl ion concentrations are greatest in a soil solution with a pH value of ______.

A soil profile consists of _________.

The lithosphere is made up of _________.

Which of the following is (are) essential plant nutrients?

Which of the following pH values represents a neutral condition?

The amount of different sizes of mineral particles in a soil defines the soil ________.

Most of the different nutrients essential for growth are supplied to plants directly from the ______.

Which of the following is considered to be a plant macronutrient?

In a load of 10 cubic meters of topsoil,approximately how many cubic meters of the volume would be solid material?

Which of the following pH values represents the most acid condition?

Soil occupies the ______part of the regolith.

The water in the soil typically differs from pure water because the soil water ________.

In a given soil,the horizon with the highest organic matter content is generally the _____ horizon.

"Topsoil" is generally equivalent to which soil horizon?

Increasing the organic matter content of a soil is likely to _____.

The layers of contrasting material found when one digs a hole in the ground are called _______.

"Subsoil" is generally equivalent to which soil horizon?

In a typical mineral soil in optimal condition for plant growth,approximately what percentage of the pore space would be filled with water and what percentage filled with air?