soils test 1

Exfoliation is caused by changes in _________ A. oxidation B. hydration C. temperature D. carbon dioxide dissolution E. all of the above

C. temperature

Which of the categories in the Soil Taxonomy system indicates properties that have implications for root growth as well as for the construction of building foundations? A. subgroup B. great group C. series D. family E. suborder

D. family

Describe Mollisols

Dark, soft soils of grasslands Among the World's most productive Production across US

describe vertisols

Dark, swelling, and cracking clay

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

texture

Of the five soil-forming factors discussed in Chapter 2 (parent material, climate, organisms, topography, and time), choose two that have had the dominant influence on developing soil properties characterizing each of the following soil orders: Vertisols, Mollisols, Spodosols, and Oxisols

) Vertisols: parent material, climate (dry season) Mollisols: organisms (grass vegetation), parent material (high calcium) Spodosols: climate (humid, high effective precipitation); parent material (sand or sand-forming) Oxisols: climate (hot, humid), time (very old)

as a society, is our reliance on soils likely to decrease or increase in the decades ahead?

- need to transform solar energy into food energy over huge areas of the earths surface - society's increased appreciation of and continued dependency on the services of natural soil based ecosystems for water, wildlife, natural cycles, and recreation. -increasing replacement of petroleum by soil grown plant products as feedstocks for chemical industry -increased replacement of finite fossil fuels with renewable plant based biofuels

How is water involved in the main types of chemical weathering reactions?

-during hydration reactions intact water molecules bind to the hydrating mineral -during hydrolysis water molecules split into H+ and Oh- ions, with the H+ often replacing a metal cation from a mineral structure - during dissolution water molecules surround ions from the soluble mineral until they become dissociated from each other - during carbonation water dissolves carbon dioxide from the carbonic acid

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

. increase the soil's water holding capacity

what are the six main role of soil in an ecosystem? for each of these ecological roles suggest one way in which interactions occur with another of the five roles

1- medium for plant growth 2- regulator of water supplies 3- recycler of nutrients and carbon 4- modifier of the atmosphere 5- habitat for soil organisms 6- engineering medium examples of interactions between these roles; plant cover(medium for plant growth)enhances infiltration of rainwater (regulator of water supplies) abundance of soil organisms (habitat for soil organisms)enhances the release of nutrients (recycler of nutrients) by the decay of plant residues (

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

5

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?

50% water and 50% air

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

6.5

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

A

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

A 1.0

"Topsoil" is generally equivalent to which soil horizon?

A horizon

Which of the following categories of Soil Taxonomy provides the greatest specificity of soil properties? A. family B. order C. suborder D. series E. great group

A. family

Igneous, sedimentary, and metamorphic are three _________. A. types of rocks B. basic classes of soils C. master horizon names D. forms of minerals E. processes of weathering

A. types of rocks

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

A; Cu

describe spodosols

Acid, sandy, forest soils Highly leached

describe ultisols

Argillic (high in clay) horizon Highly weathered and leached Developed under forests in humid tropics and subtropics

The mixed angular gravel, rock, and soil found at the foot of a slope is typical of what type of parent material? A. eolian B. glacial C. fluvial D. colluvial E. lacustrine

B. glacial

Which of the following is not considered one of the five major factors influencing soil formation? A. native parent materials B. living organisms C. valence state D. climate E. topography

C valence state

How do colluvium, glacial till, and alluvium differ in appearance and agency of transport?

Colluvium is material transported downhill mainly by gravity. It includes an unsorted jumble of all sizes of particles, often with sharp edges. Glacial till is material transported and dropped by glaciers and also includes an unsorted mixture of all particle sizes, but generally with rounded shapes. Alluvium is material transported by flowing river water and is usually sorted by particle size in difference horizontal layers with particles generally quite rounded in shape.

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

D 7.0

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

D all of the above

In which of the following horizons has the process of illuviation most likely occurred? A. O horizon B. A horizon C. C horizon D. B horizon E. E horizon

D. B horizon

Soils in this order are commonly sandy in texture, quite acidic and develop primarily under coniferous trees in cool to cold climates A. Mollisols B. Alfisols C. Andisols D. Spodosols E. Ultisols

D. Spodosols

describe aridosols

Dry soils Western part of US

What is meant by the statement, weathering combines the processes of destruction and synthesis? Give an example of these two processes in the weathering of a primary mineral

During weathering the original rocks and minerals are destroyed or broken down into smaller particles or simpler compounds, but these products may also be combined so that new minerals are synthesized. Example: orthoclase breaks down to release potassium, aluminum and silicon into the weathering solution and from these components new minerals, perhaps silicate clays, are formed.

Describe Inceptisols

Embryonic soils with few diagnostic features Weakley developed No clay accumulation

Rearrange the following soil orders from the least to the most highly weathered: Oxisols, Alfisols, Mollisols, Entisols, and Inceptisols

Entisols (least); Inceptisols; Mollisols; Alfisols; Oxisols (most weathered)

Assuming a level area of granite rock was the parent material in both cases, describe in general terms how you would expect two soil profiles to differ, one in a warm, semiarid grassland and the other in a cool, humid pine forest

Information from all parts of the chapter may be applied to this answer. If we assume that the age (time factor) is the same in both cases, then the soil differences will be mainly due to the biota and climate factors of soil formation. The soil under the cool humid pine forest will likely be acid, relatively deeply weathered, with a thick O horizon and probably a thin A horizon. The soil under the semiarid grassland will likely be more shallow, neutral to alkaline in reaction, with little O horizon, but a thick A horizon. Both soils are likely to be relatively coarse in texture.

describe entisols

Little if any profile development Relatively undeveloped Recent, new

Give an example of how parent material may vary across large geographic regions on one hand, but may also vary within a small parcel of land on the other

Loess deposits cover thousands of km2 in the central United States, but in a given landscape in this loess deposit, geologic erosion may cut down through the loess into underlying glacial till layers, exposing the latter as the main soil parent material in lower slope positions.

What is loess, and what are some of its properties as a parent material?

Loess is material transported and deposited by wind and consisting primarily of silt-sized particles. As a parent material, loess has a high capacity to hold water, but is generally quite permeable. Commonly, plant productivity is high and so is the rate of soil formation.

Describe Alfisols

Moderately leached Broad leaved forests and savannas Productive when managed properly

Describe Oxisols

Most highly weathered of the soil orders Hawaii and puerto rico

list the essential nutrient that plants derive mainly from the soil

N, P, K, S, Ca, Mg, Si, Na, Fe, Mn, B, Zn, Cu, Cl, Co, Mo, Ni

Organic matter accumulation is most pronounced in the ____.

O horizon

describe histosols

Organic soils without permafrost peat

describe gelisols

Permafrost and frost churning soils Cryoturbation- describes churning of soils

define ingenious rock

Rocks formed when molten magma solidifies

Explain why Soil Taxonomy is said to be a hierarchical classification system

Soil Taxonomy is hierarchical because at each level, several taxa are group together within a higher level category, e.g. several great groups are included in each suborder and several suborders, in turn, are included in each order

For the two soils described in question 5, make a profile sketch using master horizon symbols and subordinate suffixes to show the approximate depths, sequence, and nature of the horizons you would expect to find in each soil

The soil on the forested mountainside might include these horizons: Oi-Oa-Oe-A-E-Bw-C. The soil on the semiarid grassland plain might include these horizons: Oi-A1-A2-Bk-C.

Give two specific examples for each of the four broad processes of soil formation.

Transformations might include weathering of mica to form clay and the decomposition of plant residues to form humus. Translocations might include the upward movement of salts from groundwater to the soil surface in arid regions, and the downward illuviation of clay from the surface horizons to the B horizons. Additions might include calcium added with the deposition of dust and organic matter added with the annual shedding of deciduous tree leaves. Losses might include cations leached down out of the profile and into the groundwater and clay particles from the soil surface eroded away by runoff water.

What is the principal soil property by which Ultisols differ from Alfisols? Inceptisols from Entisols?

Ultisols have a lower percentage base saturation (<35%) deep in the profile than do Alfisols. Inceptisols have some kind of easily developed B horizon while Entisols have no B horizon.

describe andisols

Volcanic ash soils Subjected to mild weathering

define a soil

a 3d natural body

define the soil

a collection of soil contents

define soil

a dynamic natural body on the surface of the earth in which plants grow composed of air mineral and organic matter interacting with living organisms and is a product of climate (active) and vegetation (active) acting on a parent material (passive) in a specific location (topography passive) over time(neutral)

discuss how a soil, a natural body differs from soil, a material that is used in building of roadbed?

a soil is an organized three dimensional body that is a component of a landscape. mere soil is some material from such a body that can be moved around by a shovel or bulldozer

A soil pedon is ____.

a three-dimensional unit that embodies the primary characteristics of an individual soil

define weathering

all physical and chemical changes produced in rocks, at or near the earth's surface by atmospheric agents

"Subsoil" is generally equivalent to which soil horizon?

b horizon

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

e; all of the above

define geophagy

eating soil to the get the nutrients

A soil developed in transported parent materials will likely have properties related to the properties of the rock below the C horizon.

false

Alluvial parent materials are those that have been laid down in former lake bottoms.

false

Although subsoil is more difficult to obtain, it is generally equally as good as topsoil for landscaping purposes.

false

Except for some kinds of foods, modern industry has made human dependence on soils a thing of the past.

false

Glacial till is laid down by melt waters gushing out from the front of glaciers.

false

Soils developed in wind-blown parent materials such as loess are generally of little agricultural value.

false

Subsoil is typically equivalent to the O horizon.

false

The C horizons are generally more completely weathered than the other horizons.

false

The topmost horizon in most humid region forest soils is the A horizon.

false

Weathering of rocks usually is most intense in the center of a rock fragment, and gradually decreases toward the outside.

false

Where organic matter constitutes only 1 or 2 percent of the soil by weight, it has only negligible influence on soil properties.

false

While many organisms depend on the soil for nutrients and water, only a few very specialized organisms live in the soil itself.

false

define metamorphotic rock

formed from other rocks by metamorphism

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

greater attraction of water

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

horizons

define top soil

in the A horizon where life is at and is the most fertile

define subsoil

in the B horizon and stores minerals for later

define soil horizon

layer of soil approx parallel to the soil surface differing in properties of characteristics from adjacent layers below or above it

Residual parent materials are best described as __________.

materials formed by weathering of rocks and minerals in place.

define primary minerals

minerals that has not been altered chemically since disposition and crystallization from molten lava

are all elements contained in plants essential nutrients?

no plants take up elements which are not essential to the plants growth. examples are silica and sodium

define sedimentary rock

older rock under water; most common; 75% of earth

define soils

one of the individual bodies

define colloid

organic and inorganic matter with very small particle size and a correspondingly large surface area

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

rain water

define secondary minerals

resulting from decomposition of primary or from reprecipitation of products of decomposition of primary

The lithosphere is made up of _________.

rock

Igneous rocks can best be characterized as:

rocks formed when molten magma solidifies

define pedology

science that deals with formation, morphology and classification of soil bodies as landscape components

Define Edaphology

science that deals with the influence of soils on living things particularly plants including human use for land of plant growth

define solum

soil or land usually A and B horizons

describe four processes that commonly lead to degradation of soil quality

some soil degrading processes; erosion, salt accumulation, nutrient depletion and chemical pollution

define regolith

the layer of unconsolidated rocky material covering bedrock.

define soil texture

the relative proportion of the various soil separates in a soil; the way the particles are arranged

A soil profile consists of ________

the way the soil feels

Hydrolysis involves the splitting of water into its H+ and OH- components while hydration attaches intact water molecules to a compound.

true

Igneous rocks are formed when molten magma cools and solidifies.

true

Most of the water in our rivers and lakes has come in contact with and has been affected by soils.

true

Organic deposits are most common in areas where water flow over the soil surface is restricted.

true

Plants can be grown without any soil.

true

Residual parent materials have formed in place and have not been transported from one area to another.

true

Secondary minerals are recrystallized products of the chemical breakdown and/or alteration of primary minerals.

true

Soil air usually has a higher carbon dioxide content than the air in the atmosphere.

true

The A horizons are more apt to be cultivated than the E horizons.

true

The O horizons of a soil are dominantly organic horizons occurring above mineral horizons.

true

The mineral particles in soil consist of sand, silt, and clay.

true

Soil occupies the ______part of the regolith.

upper

define soil profile

vertical section of soil through all its horizons and extending into parent material roots in A horizons

define micropore

water held tightly not always available to plant, filled with water

define macropore

water removed from first by plants hold water least tightly, replace water with air generally filled with air

Glacial till is a term used to describe parent materials that:

were transported by water gushing from glacial fronts.