Soils Old Exams: Exam 1

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

A) A

Of the three horizons given, which generally has the highest organic matter content ? A) A B) B C) E

A) A

An ultisol can look like a mollisol or alfisol but is different in that it has a A) high base saturation B) low base saturation C) lots of iron or aluminum oxides

B) low base saturation

Metamorphic rocks can best be characterized as ________. A) rocks containing both feldspars and micas B) rocks formed from the recrystallization of sedimentary material C) rocks formed when molten magma solidifies

B) rocks formed from the recrystallization of sedimentary material

The four soil forming processes are A) transformatiion, hydrolysis, carbonation, redox B) transformation, translocation, additions, losses C) hydrolysis, hydration, disintegration, acidification

B) transformation, translocation, additions, losses

Which of the following categories of Soil Taxonomy provides the greatest specificity of soil properties? A) family B) series C) order

B. Series

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) 25% water and 75% air B) 25% water and 25% air C) 50% water and 50% air

C) 50% water and 50% air

A soil formed under a forest might likely have which of the following horizons that would separate it from one formed under a praire soil A) A B) B C) O

C) O

Sedimentary rocks can best be characterized as ________. A) rocks found primarily near volcanoes. B) rocks formed when molten magma solidifies C) rocks formed from the recrystallization of sedimentary material

C) rocks formed from the recrystallization of sedimentary material

Mechanical weathering processes result in ________. A) the hydrolysis of minerals through frost action B) the decomposition of primary minerals C) the disintegration of rocks due to differential expansion of minerals

C) the disintegration of rocks due to differential expansion of minerals

Igneous, sedimentary, and metamorphic are three ________. A) forms of minerals B) processes of weathering C) types of rocks

C) types of rocks

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

D) all of the above

T/F Epipedons are diagnostic horizons that are one of the primary means of classifying soils in the United States.

False

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

False

T/F Sandstones are good examples of metamorphic rocks.

False

T/F Subsoil is typically equivalent to the O horizon.

False

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

False

T/F Chemical weathering is accelerated by water, oxygen, and organic and inorganic acids moving down through the regolith.

True

Organic matter accumulation is most pronounced in the ________. A) A horizon B) B horizon C) E horizon

A) A horizon

A Bt horizon indicates a zone of illujvation dominated by A) clay B) tillage C) iron and aluminum oxides

A) clay

The reaction: CaSO4 x 2H2O + 2 H2O —> Ca2+ +SO4 2- +4 H2O is an example of ________. A) dissolution B) acidification C) hydrolysis

A) dissolution

The subordinate distinction "g" means the soil in that horizon is A) gleyed B) strong C) gooey

A) gleyed

Compared to silt, clay-sized soil particles are characterized by ________. A) greater attraction for water B) less capacity to hold nutrients in plant-available forms C) greater proportion of primary minerals

A) greater attraction for water

The identifiable layers of material found when one digs a hole in the ground are called ________. A) horizons B) pseudoliths C) regoliths

A) horizons

Granite is an example of a(n) ________. A) igneous rock B) sedimentary rock C) eolian parent material

A) igneous rock

Soil occupies the ________ part of the regolith. A) upper B) younger C) lower

A) upper

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

A) valence state

In a load of 8 cubic meters of topsoil, approximately how cubic meters of the volume would be solid material? A) 7.5 B) 4 C) 5

B) 4

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

B) B horizon

Which landscape position would likely have the most horizonations (highest number of horizons). A) Slopes B) Bottomlands C) Uplands

B) Bottomlands

Silicate clay loss is most notable in the ________. A) A horizon B) E horizon C) B horizon

B) E horizon

Which of the following statements is correct? A) Limestone parent materials enhance the process of acidification. B) Soils on hillsides tend to be shallower (less horizonation) than those on level lands. C) Calcium carbonate accumulation is more prominent in humid than in arid regions

B) Soils on hillsides tend to be shallower (less horizonation) than those on level lands.

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

B) texture

The lower layers in a soil profile (i.e. B or C) are the A) at the same weathering stage as the upper layers B) the least weathered C) the most highly weathered

B) the least weathered

If you wanted to find a soil where physical weathering dominated over chemical breakdown you would be most apt to find it in ________. A) a coastal plain area of Delaware B) a lacustrine deposit in Minnesota C) a desert region of Arizona

C) a desert region of Arizona

A soil pedon is ________. A) a category of Soil Taxonomy B) generally larger in area than a polypedon C) a three-dimensional unit that embodies the primary characteristics of an individual soil

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

Secondary minerals are most prominent in the ________ fraction of soils. A) silt B) sand C) clay

C) clay

Colluvial parent materials are best described as A) water transported B) marine based C) gravity transported

C) gravity transported

The reaction: mica + H2O = K+ + OH- + acid clay is an example of ________. A) physical weathering B) carbonation C) hydrolysis

C) hydrolysis

The element most often involved in oxidation reactions as minerals weather is ________. A) aluminum B) magnesium C) iron

C) iron

Transported parent materials are best described as ________. A) materials formed by weathering of rocks and minerals in place. B) materials more dominant in Iowa than in the Southern United States. C) materials transported from one location to another by water, ice or wind.

C) materials transported from one location to another by water, ice or wind.

A soil formed under a praire might likely have which of the following epipedons A) ochric B) salinic C) mollic

C) mollic

In which of the following epipedons is the base saturation generally highest? A) alfic B) ochric C) mollic

C) mollic

In which of the following epipedons is the organic matter level generally lowest? A) histic B) mollic C) ochric

C) ochric

An A horizon with a sharp, distinct boundary at about 6 inches due to cultivation would most likely have which subordinate distinction A) s B) q C) p

C) p

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 set of layers seen in a vertical cross section of a soil

C) the set of layers seen in a vertical cross section of a soil

T/F Marine sediments are typical parent materials in coastal plain areas.

True

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

True

T/F The broadest category of classification in Soil Taxonomy specifies 12 soil orders.

True

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

True