Fundamental of Soil Final (2018)

Roots growing into a crack in rock is called root ______.

Wedging

It is recommended to perform soil health evaluations.

Yearly

There are ______ soil capability classes that are identified by _______.

Eight and Roman Numerals

Subclass designation for agricultural land with limitation due to water or wind erosion.

e

True/False Chunks of soil caused by tillage are called aggregates or peds

False

True/False Soil temperature is fairly static and not subject to the influences of many factors

False

True/False Texture in large areas of soil can be modified easily

False

True/False USDA has identified 14 different soil textural classes

False

Sand, silt, and clay make up the ________ earth fraction of soil used to determine texture.

Fine

Which one of the topographical (relief) position would be most likely to develop soils with the deepest soil horizons.

Foot-slope

Identify the three-phase system used to describe the soil matrix?

Gas, Liquid, and Solid

Macro-pores in the soil matrix provide for the movement of ______ and while micro in the soil matrix provide the retention

Gases, Water

Debris dropped in place to form deposits during glacier melting

Glacial till

Which of the following is not affected by soil temperature? A.) Biological activity of soil microorganisms B.) Weed emergence C.) Gleying D.) Water and nutrient availability E.) Seed germination F.) Root Growth

Gleying

Which kind of soil structure would be typical for a good seed-bed?

Granular

Which one of the following is a negative effect of soil temperatures that are too high? A.) Diminishes the roots ability to absorb water B.) restrict germination C.) nutrient deficiencies D.) Destroys pathogens weed seed, and insects E.) heat stress that inhibits plant growth

Heat stress that inhibits plant growth

Horizon that accumulates organic matter and is referred as the top-soil

Horizon A

Soil horizon that would be considered the zone with the most biological activity

Horizon A

Horizon with the greatest elevation; depleted in clay, chemicals, organic matter, light color (bleached appearance)

Horizon E

One of the processes of chemical weathering when water molecules are added to another substance

Hydration

The concept of soil health also means that healthy soils have the ability to sustain

Plant and animal life and productivity, soil biodiversity, maintain and enhance water and air quality, support human health and wildlife habitat

Which one of the following choices list the five soil forming factors?

Parents material, climate, topography/Relief, time, biosphere

Define motteled

Patches of different colors that suggest the soil is water logged fro part of the year

A small body of soil selected for careful study, usually 1 meter by 1 meter in dimension?

Pedon

Soil structure refers to the way soil particles clump together into larger units. These large units are called ______.

Peds or aggregates

Knowing the drainage class of soil is helpful when building a _____.

Pond, wetland, road, and basement.

The mineral soils highest in organic matter tend to form in the...

Prairie

Soils formed in place from the left overs of weathered bedrock.

Residual soils

Define dark brown and black

Result from high levels of organic matter

Define light Brown, yellow to red

Result from oxidized iron minerals

Define bluish-grey

Result from reduced iron compounds

In the ribbon or feel test for determining soil texture, which of the following indicates loamy sand?

Ribbons shorter that 1 inch

Good structure in the subsoil improves _____.

Root Elongation

What is the textural class of soil that is 10% clay and 35% sand? (use textural class triangle)

Silt Loam

Which of the following textural classes has the largest potential plant available water? A.) Sandy loam B.) silt loam C.) silty clay loam D.) clay

Silt Loam

Define Clay

Small particles; many small pores, consisting mostly of tiny sheet-like crystals

Define Physical Property

Soil characteristics that can be seen and felt

The ideal soil matrix composition for most plants

45% minerals, 5% Organic Matter, 25% Air, 25% Water

If a field has an 11 foot change in elevation over a distance of 1000 feet, the slope ______%

1.1

The bulk density of 100 cm^3 of dry soil that weighs 145g is _______ g//cm^3

1.45

Organic soils contain ______ % or more organic matter.

20

The area of a rectangular field that is 1250 ft long and 700ft wide is _____ acres.

20

Define Loam

A soil in which sand, silt, and clay contribute equally to the soil's properties

If a 50 acre field is conventionally tilled prior to planting, at least initially, what happens to porosity, permeability, and bulk density.

After tillage, soil is fluffed up at the surface, and porosity and permeability rise while bulk density declines.

In a permeable soil, what moves through the soil easily?

Air, water, and roots

Which is not a way climate affects soil development

Amount of sedimentary rock in parent material

The direction the slope is facing related what aspect of topography

Aspect

List three ways to preserve soil tilith.

Avoid traffic over soil, work at proper moisture, and use light equipment

A horizon that contains illuviated clay is the ______ horizon.

B

Horizon referred to as the subsoil; zone accumulation (illuviation)

B Horizon

Iowa soil health evaluation is tool designed to help farmers, operators, and other agricultural professionals evaluated the health of soil using soil _______ and ________ indicators.

Biological, Physical

Which of the following best defines particle density? A.) What soil would weigh if there were no pore space B.) The density of a soil's solid particles only C.) Both

Both

Soil Development that starts with the ____ horizon

C

What soil textures has the greatest % porosity?

Clay

Which of the soil textures listed below has the highest total porosity and the lowest bulk density? A.) Silt loam B.) loamy sand C.) sandy loam D.) clay

Clay

Soil deposits caused by gravity

Colluvial

Which of the following does not belong in a list of ways in which soil texture affects growing plants? A.) Fine or course particles B.) Water infiltration and percolation C.) color D.) stickiness

Color

Define Granular Structure

Commonly found in the A horizons; peds are 1/25 to 2/5 inch; rounded in form; considered the most desirable of structures

Chemical weathering process when solid passes into solution?

Dissolution

Which of the following choices is not true of bulk density? A.) Does not include pore space B.) Includes pore space, is measured using oven-dry soil C.) Used as an indicator of soil quality

Does not include pore space

Land capability class ______ soils have very severe limitations that restrict the choice of plants or require very careful management, or both

IV

Which of the following can decrease bulk density? A.) Burning crop residues B.) equipment wheel traffic C.) tillage D.) incorporating compost

Incorporating compost

Which of the following is not typical for a soil temperature that is too low? A.) Nutrient Deficiency B.) Restricts germination C.) Microbial activity slows down D.) Diminishes the ability of roots to absorb water E.) Increases the breakdown of soil minerals

Increases the breakdown of soil minerals

The following are types of soil tilth injuries except ____. A.) Puddling B.) Clods C.) Surface crusts D.) Direct aggregate destruction E.) Infiltration F.) Compaction

Infiltration

Soil Characteristics and properties that are identified as stable in the soil are called _______ traits, while those characteristics and properties that are classified as unstable in the soil called ____ traits.

Inherent, dynamic

Which one of the following choices is not related to the C horizon?

Is sometime referred to as zone of eluviation

Land capability subclass code used to the describe soils with root zone and tillage problems as their main limitations

Land capability subclass s

Define Sand

Large particles; composed mainly of weathered grains of quartz or other minerals

Sedimentary rock rich in calcium carbonate derived from shells of sea organisms and mineral calcite, including dolomite, which is rich in calcium an magnesium carbonate

Limestone

______ soils have the ideal texture for the production of most plant.

Loamy

Two most predominant parent materials of Iowa soils

Loess, Glacial till

Define Bulk Density

Mass of a volume of undisturbed oven-dry soil

Define White or light grey

May indicate that chemicals have leached out or may be due to accumulations of lime, gypsum, or other salts

Define infiltration

Measure of the rate of water movement into a soil

Define Silt

Medium-sized particles; silky or powdery to the touch

Rock formed by heat and pressure in earth is called _____.

Metamorphic

Smaller spaces in soil that retain water for plant use?

Micropores

Predominate soil order found in Iowa

Mollisols

Within the time frame of a human generation soil would be considered a _____ resource.

Non-renewable

Which one of the following choice is a form of physical weathering? A.) Hydration B.) Hydrolysis C.) Dissolution D.) Oxidation-Reduction E.) none of the above

None of the above

The first horizons to typically form from parent materials is the _____ horizon.

O

Horizon made up of wholly or partially decayed plant and animal debris; undisturbed soil

O Horizon

Which one if the following choices identifies the master horizons

O(organic matter), A(top soil), B(Sub-soil), C(parent-material), R(bedrock), and E(Eluviated soil)

The upper, weathered part of soil profile consisting of the A, B, and E (if it exists) horizons are referred as the true soil or _______.

Solum

Under warm, moist conditions a soil profile will develop _____ horizons in a ______ period of time compared to soil under dry, cool conditions.

Strong, Shorter

What increases as a soil's clay content increases?

Surface Area

Define Prismatic Structure

Tend to occupy lower B and C horizons; peds are 1/5 to 4 inches, forming angular columns that stand upright in the soil

Soil structure modifies the physical properties of soil _____.

Texture

The most fundamental soil property that influences other soil traits is ________.

Texture

Define Permeability

The ease with which air, water, and roots move through soil

The four soil-forming processes do not include which of the following: A.) Loss B.) Transpiration C.) Translocation D.) Addition E.) Transformation

Transpiration

True/False Pressure applied to the soil surface causes compaction.

True

True/False Soil scientist divide mineral particles into size groups called soil separates

True

True/False Tilth is a general term for the physical condition of tilled soil and takes into account texture, permeability, structure, and consistence; how easy the soil is to till; how good a seedbed can be make; how easily seedlings emerge; and how easily roots will grow

True

True/False Total pore space measures the soil volume that holds air and water

True

True/False Wet, moist, and dry are descriptive terms for soil consistence moisture levels

True

Define blocky structure

Typical of many B horizons; peds are 1/5 to 2 inches

Define Platy Structure

Usually found in E horizons; peds are large but thin, and arranged in overlapping horizontal layers

Which soil capability classes are not suited to row crop, even with varying level of management?

VI, VII, VIII

Soil is a medium for plant growth because it provides

Water, Oxygen, Nutrients, and Anchorage