Soils Final
True or false: Mollisols are found mostly near areas of natural pasture or rangeland.
True
True or false: The broadest category of classification in Soil Taxonomy specifies 12 soil orders, 11 of which are for mineral soils.
True
In soils of which great group would you most likely find wide surface cracks during periods of dry weather? A) Calciusterts B) Argiaquolls C) Kandiaquults
A
"Subsoil" is generally equivalent to which soil horizon? A) A B) B C) C
B
1 mole of Al3+ contains how many moles of positive charge? A) 3 B) 27 C) 15
A
A soil with a gritty feeling likely has a high percentage of which soil separate? A) sand B) silt C) clay
A
A watermelon grower has asked you for your recommendation on an irrigation method. Based on your experience which of the following methods would you recommend. (Watermelons don't like wet soils) A) Drip irrigation B) flood C) center pivot
A
Argillic horizons are characterized by: A) accumulation of silicate clays B) organic matter accumulation C) high levels of iron and aluminum oxides
A
Based on the figure, which legal land description is correct? A) T19N, R 15E, sec 28, SW1/4, B) T19N, R15E, sec 15, NW ¼, E1/2 C) T19N, R11W, sec 12, NW1/4
A
Erosion processes consist of three steps: Detachment, Transport, and Deposition. To control water erosion, we must devise methods to stop what? A) Detachment of the silt fraction from the soil aggregates B) Transport of the silt fraction through the water C) Deposition of the sand particles at the delta
A
Given the family: fine-sandy, smectitic, mesic Aquic Haplaudalf, what do you know about this soil A) it likely formed under a forest B) it is dominated by kaolinitic clays C) it has a deep A horizon
A
Given the information in the table, calculate the CEC of this soil 1 Kg of soil contains 6 cmolec as Ca2+ 2 cmolec as Mg2+ 1.5 cmolec as K+ 1 cmolec as Na+ 1 cmolec as Al3+ 1 cmolec as H+ A) 12.5 B) 30 C) 20.5
A
If you start with 40 g of soil, and the first hydrometer reading is 22 g/L while the second is 14 g/l, what is the soil texture? A) clay loam B) sandy loam C) loam
A
If you start with 40 g of soil, and the first hydrometer reading is 32 g/L while the second is 8 g/l, what is the soil texture? A) silt loam B) silty clay C) sandy clay loam
A
Igneous rocks can best be characterized as: A) rocks formed when molten magma solidifies B) rocks containing a mixture of primary and secondary minerals C) rocks formed from the recrystallization of sedimentary mineral
A
In a given soil, the mineral horizon with the highest organic matter content is generally the ______ horizon (of the choices below) A)A B)E C)B
A
Increasing the organic matter content of a soil is likely to: A) increase the soil's water holding capacity B) decrease the soil's water holding capacity C) have no effect on water holding capacity
A
Mechanical weathering processes results in: A) the disintegration of rocks due to differential expansion of minerals B) the hydrolysis of minerals through frost action C) the decomposition of primary minerals
A
Organic matter additions to a soil can decrease: A) Db B) porosity C) Dp
A
Septic systems are designed to ______ household waste A) remove and treat B) back up C) remove
A
Soil A has a profile with a lot of yellow and red colors while soil B has a prodominately gray profile. Of the two soils, Soil A is more apt to be characterized by an abundance of A) Fe3+ ions B) S2- ions C) Mn4+ ions
A
Soil crusting is due to aggregate: A) dispersion B) formation C) flocculation
A
Some soil colloids exhibit positive charges under highly acid conditions. To what are these charges likely due? A) protonation of some hydroxy groups by excess H+ ions B) the release of some OH- ions leaving an unsatisfied positive charge on the colloid C) substitution of lower valent atoms for higher valent atoms in the octahedral sheet
A
Subsurface land drainage is beneficial because ________. A) it increases the depth of root penetration in the soil B) it increases the availability of iron and manganese in acid soils C) it slows down the rate of soil warming in the spring
A
Surface ditches are an effective way to remove large volumes of water A) before it enters the soil B) after the soil as reached saturation C) after it enters the soil and filled the micropores
A
The five soil forming factors are: A) Climate, organisms, time, topography, parent material B) Climate, organisms, time, hydration, erosion C) Transformations, weathering, the horizons, topography, and hydrolysis
A
The hydrologic cycle is the cycling of water from the atmosphere to the ________, and then from the soil to either surface water or groundwater, and then to the oceans and back to the atmosphere A) Soil B) Air C) Water
A
The layers of constrating material found when one digs a hole in the ground are called______ A) horizons B) pedons C) pseudoliths
A
The map units on a detailed soil map in a county soil survey report (same as Web Soil Survey) are most likely to be labeled with names from which category of Soil Taxonomy? A) series B) order C) suborder
A
The matric potential of soil water ________. A) is not influenced appreciably by the force of gravity B) is lower in a sandy soil with 20 percent soil water than in a clay soil with same percentage of moisture C) is little affected by soil solids
A
The process of soil formation is a complex interaction of A) the four soil forming processes and five soil forming factors B) the five soil forming processes and four soil forming factors C) The illuviation of organic matter, clay, and iron and aluminum oxides
A
The swelling/shrinking tendency of some silicate clay minerals is due primarily to ________. A) the movement of water molecules in and out of the interlayers of the crystal B) the presence of cations attracted by the negative charges on the internal surfaces C) expansion in the width of the interlayers due to movement of larger ions such as K+
A
Two problems associated with this partcular issue are poor seedling emergence rates and high runoff rates. What is the problem? A) Soil crusting B) Aggregate flocculation C) Cation bridging
A
What drives the Soil-Plant-Air Continuum A) Water potential B) Root suction C) Solar radiation
A
What is the bulk density of a soil with a wet weight of 57 g, a dry weight of 53 g and occupies 37 cm3 A) 1.43 g/cm3 B) 1.31 g/cm3 C) 2.65 g/cm3
A
Which of the following disintegration (physical breakdown) processes has the largest effect on rocks A) Temperature B) Abrasion C) Plants and Animals
A
Which of the following is not a characteristic of soil colloids? A) low water holding capacity B) very small size C) electronegative charges
A
Which of the following is not considered one of the five major factors influencing soil formation? A) valence state B) native parent materials C) living organisms D) climate E) topography
A
Which of the following practices is(are) useful in stabilizing surface soil structure? A) all of the answers B) minimizing tillage C) use of organic mulches D) use of green manure crops E) growing grass sod
A
Which of the following statements is correct? A) Soils on hillsides tend to be shallower than those on level lands B) Highly weathered end products have been subject to weathering for short periods fo time C) Limestone parent materials enhance the process of acidification
A
Which of the following will decrease the evaporation (E) from the soil surface? A) all of the above B) plastic mulch C) the use of no-till culture D) adding straw mulch to the soil surface
A
You are consulting with a farmer about their plans for the next few years. You have Web Soil Survey open and notice that one of the fields has a Bg horizon 12" depth with a prodominently grey background . From this information, you conclude which of the following A) The soil is poorly drained the the crops to be grown should be chosen carefully B) There are no limitiations to crop growth. C) The soil is somewhat poorly drained but the crops to be grown are hardy and can take the water
A
A soil has a thick black A horizon, a distinct B horizon, has reasonably stable soil structure, and was formed under grassland natural vegetation. In which suborder is it most likely classed? A) udults B) udolls C) ustalfs
B
A soil profile consists of ______ A) the sum of chemical and physical data known about a soil B) the set of layers seen in a vertical cross section of a soil C) the spatial boundaries of a particular soil
B
A subsoil that has both a "g" and a "t" subordinate distinciton (Btg) can be expected to have: A) a glazed appearance and transformations B) a clay accumulation and grey colors C) a good soil structures and tillage
B
Additions to the soil primarily affect the soil profile through A) wind blown sand B) organic matter C) water movement
B
An alkaline soil contains 20% clay and 1.5% humus. If the pure clay has a CEC of 40 cmolc/kg and the humus 200 cmolc/kg, calculate the CEC/kg of the soil. A) 16 B) 11 C) 14
B
An ultisol can look like a mollisol or alfisol but it is different in that it has a: A) high base saturation B) low base saturation C) a lot of iron and aluminum oxides
B
Capillarity in soils ________. A) is independent of the matric potential in soils B) involves both adhesion and cohesion C) is enhanced by the symmetrical nature of the water molecule
B
Compared to silt, clay-sized soil particles are characterized by: A) greater proportion of primary minerals B) greater attraction for water C) less tendency to form hard clods when dry
B
Decreasing the organic matter content of a soil is likely to ________. A) increase soils structure (strengthen soil aggregates) B) decrease soils structure (disperse soil aggregates) C) have no effect on the soil structure
B
If the soil water potential is positive, it is due to A) matric potential B) gravitational potential C) osmotic potential
B
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 25% air B) 50% water and 50% air C) 10% water and 90% air
B
In the Soil-Plant-Air continuum, once the water impacts the soil, it can either infiltrate into the profile or A) be taken up by the plants B) runoff C) puddle
B
In which of the following horizons has the process of illuviation most likely occurred? A) A horizon B) B horizon C) E horizon
B
In which of the following situations would you expect downward movement of soil water through the profile to be most rapid? A) sandy loam in upper layers with a layer of coarse gravel underneath B) uniformly textured sandy loam profile C) sandy loam in upper layers with a clay band underneath
B
Muscovite mica is an example of a(n) ________. A) secondary mineral B) igneous rock C) sedimentary rock
B
Of the various types of drain systems, open ditch systems are most practical and economical for use on ________. A) soils with a deep water table B) poorly drained soils with sandy profiles C) vertisols
B
One of several hydric soil indicators is: A) a long hydroflux B) loss of Fe C) the presence of NO3-
B
Practices that decrease organic matter and increase tillage can be expected to most significantly increase the _____ in a soil A) macropores B) bulk density C) fineness of texture
B
Secondary minerals are most prominent in the ________ fraction of soils. A) sand B) clay C) silt D) organic
B
Silicate clay accumulation is most common in the ______. A) B horizon B) C horizon C) A horizon
B
Soil occupies the _____ part of the regolith. A) Younger B) Upper C) Lower
B
Soil structure describes the ________ of particles in a soil. A) colors B) arrangement C) sizes
B
The element most often involved in oxidation reactions as minerals weather is ________. A) magnesium B) iron C) aluminum
B
The expression, P - ET - SS estimates the ________ a watershed. A) evaporation from B) discharge volume from C) soil water content of
B
The four soil formation process are A) montmorillinosis, oxidation, illuviation, and mineralization B) translocation, transformation, additions, and losses C) weathering, oxidation, exfoliation, and acidification
B
The negative charges associated with vermiculite clay crystals are due mostly to ________. A) isomorphous substitution of Mg for Al in the octahedral sheet B) isomorphous substitution of Al for Si in the tetrahedral sheet C) isomorphous substitution of Si for Al in the tetrahedral sheet
B
The presence of rocks such as shale and sandstone indicate the existence of ________. A) Old mountain ranges B) Ancient seas C) A high water table
B
The reaction "mica + H2O → K+ + OH- + 6 HAlSi3O8 (acid clay)" is an example of ________. A) hydration B) hydrolysis C) oxidation
B
The three characteristics to look for in a wetland are: A) A long hydroperiod, hydrophobic plants, yellow colors in the profile B) a wetland hydrology, hydric soils, hydrophytic plants C) good soil structure, a lot of reds and yellows in the profile, a silt loam texture
B
Two soil samples, A and B, at different soil moisture levels are placed in contact with each other. Water will more likely move from soil A to soil B if their water potentials, expressed in kPa, are ________. A) A=-100; B=-50 B) A=+5; B=-5 C) A=-5; B=-5
B
We must use our soils wisely and protect them because__________. A) they are a never ending source of clean water and plant nutrients B) they are a reuseable, but not renewable, resource C) they are easily formed and thus, a renewable resource
B
Which of the following irrigation systems produces the most biomass per unit of water applied? A) flood irrigation B) drip irrigation C) furrow irrigation
B
Which of the following is a characteristic of the clay fraction but not the sand or silt fractions of the soil? A) has medium to large pore space B) shaped like flakes or platelets C) has no chemical or physical properties
B
Which of the following refer to macropores spaces A) tend to increase the bulk density B) allow for rapid water movement C) usually filled with water
B
You are working with a soil colloid known to have a cation exchange capacity of about 14 cmolc/kg of clay and little tendency to swell when wetted. Which of the following is it most apt to be the dominant clay mineral in this soil? A) vermiculite B) kaolinite C) fine-grained mica
B
1 mole of Al3+ contains how many Al3+ ions? A) 6.02x1046 B) 12.04x1023 C) 6.02x1023
C
30 g of Mg2+ (M.W. =24) contains how many moles of positive charge? A) 1.5 B) 17 C) 2.5
C
A cool, wet climate is likely to produce soils high in ______, while a hot, wet climate is likely to produce soils high in_______. A) horizonation, vegetation B) sand, silt C) organic matter, iron and aluminum oxides
C
A septic system needs soil to allow the waste water to move_______ enough to filter impurities A) fast B) the waste water should not move at all. C) slowly
C
A soil with a Bx horizon is likely to have a ________ indicating a potential perched water table A) a subsoil with a very low bulk density B) deted B horizon C) fragipan
C
A soil with grey mottling occuring at >30" belongs to which drainage class A) moderately well drain B) poorly drained C) well drained
C
An A horizon with a sharp, distinct boundary at about 6 inches due cultivation would most likely have which subordinate distinction A) sb B) e C) p
C
Dull gray colors are characterized by ________. A) mixed hues B) high color values C) low chromas
C
Given that you have 80 g of Ca2+, how many cmolec are present (M.W. of Ca2+ = 40g, 100 cmolc = 1mole) A) 40 B) 4 C) 400
C
Given the information in the table, calculate the Base Saturation of this soil 1 Kg of soil contains 6 cmolec as Ca2+ 2 cmolec as Mg2+ 1.5 cmolec as K+ 1 cmolec as Na+ 1 cmolec as Al3+ 1 cmolec as H+ A) 30% B) 80% C) 84%
C
Humus is an important soil colloid. It is like 2:1 type minerals in which one of the following characteristics A) influence of isomorphous substitution B) structural framework of the particles C) capable of adsorbing cation
C
If you dug a deep hole in your back yard and water started to seep into the hole it would fill the hole up to ________. A) the infiltration rate B) field capacity C) the water table
C
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 humid region in Brazil B) a coastal plain area of Delaware C) a desert region of Arizona
C
If you were seeking a soil colloid with a high capacity to adsorb cationic pollutants, but also with a consistent capacity to do so even as the pH varied form 4.0 to 7.5, which of the following would you choose? A) chlorite B) kaolinite C) montmorillonite
C
Igneous, sedimentary, and metamorphic are three ______ A) master horizon names B) basic classes of soils C) types of rocks
C
In a soil with a bulk density of 1.2 Mg/m3, what is the % pore space (Assume Dp = 2.65 Mg/m3) A) 47% B) 60% C) 55%
C
In a soil with a bulk density of 2.2 Mg/m3, what is the % pore space (Assume Dp = 2.65 Mg/m3) A) 50% B) 35% C) 17%
C
Living organisms can affect the soil profile through A) structural stability B) profile mixing C) all of the above D) organic matter accumulation
C
Organic matter is extremely important in the soil and has been call a master variable, why? A) If we change the organic matter type or content in the soil, nothing else is affected B) While it's present in the soil, it's not very important C) If we change the organic matter type or content in the soil, a lot of other soil properties are affected
C
Plant roots obtain access to soil water in which of the following ways? A) The roots contract and leave room in the pores for the water to move in. B) Water vapor moves from the wet soil areas to the root surfaces. C) Water flows to the roots by capillarity.
C
Secondary minerals are most prominent in the ________ fraction of soils. A) sand B) silt C) clay
C
Soil quality is a term used to describe the soils___________. A) the ability of the soil to purify water B) amount of nutrients a soil can provide C) ability to carry out ecological functions
C
Soils rich in which type of clay would not provide the best site on which to build a home? A) kaolinite B) Fe, Al oxides C) smectite
C
Some cations are important in remediating soil crusting problems because they ________. A) stabilize macro aggregates B) are active in the formation of soils crusts C) help to flocculate the soil colloids
C
The B horizon can be high in A) Aluminum oxides B) Clay C) All of the above D) Iron oxides
C
The amount of different sizes of mineral particles in a soil defines the soil _______ A) pore space B) structure C) texture
C
The electronegative charge on 2:1 type silicate clays is due primarily to ________. A) the preponderance of tetrahedral sheets compared to octahedral sheets B) extremely small size of the individual colloid particles C) isomorphic substitution of one metallic atom for another in the crystal structure of the clay
C
The following are characteristics of a water molecule. A) The two H atoms are on diametrically opposite ends of the molecule B) It is attracted to surfaces with negative but not positive charges. C) It has a positive and a negative side.
C
The four soil forming processes are: A) Erosion, losses, evaporation, and disintegration B) Hydrolysis, hydration, additions, and losses C) Transformation, translocation, additions, and losses
C
The transformation process changes: A) fertile soils to infertile soils B) the location of primary and secondary minerals in the soil profile C) primary minerals to secondary minerals and highly resistant end products
C
Under which of the conditions below will organic matter decay be the fastest A) soil oxygen < 10% B) Redox measure < 320 mV C) Redox measurement > 400 mV
C
Using the Feel Method, a soil creates a medium ribbon when pinched between the thumb and forefinger. The ribbon is particularly smooth. What is the most likely soil texture. A) silt loam B) clay C) silty clay loam
C
What happens to permanent charge as the pH of the soil increases A) it increases B) it decreases C) nothing
C
What is the bulk density of a soil with a wet weight of 55 g, a dry weight of 43 g and occupies 35 cm3 A) 2.65 g/cm3 B) 1.3 g/cm3 C) 1.22 g/cm3
C
Which of the following best characterizes the field capacity of a soil? A) maximum capacity of a soil to hold water B) soil with water potential of -15 bar C) water content of a soil with water potential of about -0.1 to about -0.3 bar
C
Which of the following categories of Soil Taxonomy provides the greatest specificity of soil properties? A) order B) great group C) family
C
Which of the following is not a secondary mineral? A) montmorillinite B) vermiculite C) plagioclase feldspar
C
Which of the following is not a textural class name? A) loam B) clay C) sandy silt
C
Which of the following is true? A) A mature soil profile must have all of the master horizons to be considered soil B) the B horizon is a zone of eluviation C) a mature soil does not need to have all of the master horizons to be considered a soil
C
You are preparing to buy a lot for a house. While looking over some land you take a few minutes to dig a hole and check for the presence of slickensides. The slickensides indicate the presensce of a/an ______ which would not be a good place to build. A) ultisol B) alfisol C) vertisol
C
You find that the CEC of a sandy loam soil at pH 5.0 is 8 cmolc/kg and at pH 8.2 it is 14 cmolc/kg. What is the most likely reason for this difference? A) removal of Al3+ ions from the exchange complex at higher pH B) increase in the pH-dependent charges on 2:1 type silicate clays C) ionization of carboxyl and phenolic groups to release H+ ion
C
"Topsoil" is generally equivalent to which soil horizon? A) C B) D C) B D) A E) E
D
An important part of the definition of soils is that: A) On the surface of the earth B) Unconsolidated material C) Able to support plant growth D) All of the above
D
Organic matter accumulation is most pronounced in the ________. A) B horizon B) C horizon C) E horizon D) O horizon
D
The water in the soil typically differs from pure water because the soil water: A) contains mineral nutrients B) is restrained in its flow by attraction to particle surfaces C) none of these D) contains organic compounds E) All of these
E
True or false: A tetrahedral sheet is characterized by a plane of aluminum atoms surrounded by oxygen and hydroxyl groups.
False
True or false: Although subsoil is more difficult to obtain, it is generally equally as good as topsoil for landscaping purposes.
False
True or false: Epipedons are diagnostic subsurface horizons that are one of the primary means of classifying soils in the United States.
False
True or false: Except for some kinds of foods, modern industry has made human dependence on soils a thing of the past.
False
True or false: Isomorphous substitution involves the substitution of a tetrahedral sheet for an octahedral sheet.
False
True or false: Polysaccharides produced by soil microbes and similar synthetic polymers applied to soils are largely responsible for the crusts that form when rain follows tillage.
False
True or false: Sandstones are good examples of metamorphic rocks.
False
True or false: Soil, like concrete and steel, is a standard construction material. Its properties are well characterized and predictable so that standard building foundation designs can be used uniformly at all building sites of a given topography.
False
True or false: Soils classified as Inceptisols have the least well developed profiles of those in any order in the Soil Taxonomy system.
False
True or false: Subsoil is typically equivalent to the O horizon.
False
True or false: The categories of Soil Taxonomy can be listed from the broadest (first) and most specific (last) as: order, suborder, great group, subgroup, series, family.
False
True or false: The polarity of water helps account for the attraction of water molecules for each other.
False
True or false: The water potential in soils is generally considered lower than that in the atmosphere.
False
True or false: While 2:1 type clays have significant internal surfaces, their external surfaces are generally much more extensive.
False
True or false: A polypedon, or individual soil, is a group of closely related pedons that conceptually approximates what in the United States is called a soil series.
True
True or false: A, B, C, and E horizons can be found in any true soil.
True
True or false: Evaporation from the soil surface (E) is determined to a large degree by soil surface wetness.
True
True or false: Hydrolysis involves the splitting of water into its H+ and OH- components while hydration attaches intact water molecules to a compound.
True
True or false: Igneous rocks are formed when molten magma cools and solidifies.
True
True or false: Isomorphous substitution involves the substitution of one ion for another based on size.
True
True or false: Organic matter distribution in the profile is a significant criterion for differentiating epipedons.
True
True or false: Soil air usually has a higher carbon dioxide content than the air in the atmosphere.
True
True or false: Soil and crop management generally has a greater influence on evaporation from the soil surface (E) than on transpiration (T) from leaf surfaces.
True
True or false: The cation exchange capacity of humus increases if pH increases.
True
True or false: The mineral particles in soil consist of sand, silt, and clay.
True
True or false: The osmotic potential is dependent upon the presence of salts and other solutes in the soil.
True
True or false: The two most significant characteristics of the classification system used in the United States are a unique system of terminology and focus on measurable soil properties as a primary basis for the classification.
True
True or false: Tillage when the soil is too wet is likely to increase the soil bulk density.
True