SSC Final Exam
Soil scientists generally map the soils in a landscape by sampling the soil in ________. a. pre-determined a grid-like geometric pattern of evenly spaced points b. auger holes made mostly near expected soil boundaries c. four soil pits, one dug in each corner of the area to be mapped d. the center of the suspected soil mapping unit e. a computer-calculated pattern of random points
b
Soils rich in which type of clay would provide the most troublesome site on which to build a home? Select one: a. Fe, Al oxides b. smectite c. chlorite d. kaolinite e. fine-grained micas
b
The amount of different sizes of mineral particles in a soil defines the soil ________. a. solution b. texture c. pore space d. structure e. profile
b
The bulk of gaseous interchange in soils takes place by ________. a. dissolution in water b. diffusion c. respiration d. mass flow e. partial pressure of N2
b
The element most often involved in oxidation reactions as minerals weather is ________. a. copper b. iron c. silicon d. magnesium e. aluminum
b
The nomenclature of Soil Taxonomy is characterized by all but which one of the following statements? a. The names are based on measurable properties and not on presumed modes of genesis. b. The names give a clear indication of the modes of genesis of the soil. c. Soil names (except for series level) identifies major soil characteristics. d. The names of the orders all end with the letters sols. e. The subgroup name also tells you the great group, suborder, and order names.
b
The total phosphorus lost from various watersheds is most closely correlated with ________. Select one: a. high percentage of forested land b. high soil erosion c. high soil permeability d. low soil CEC e. extent of artificial drainage
b
Which of the following describes a soil that likely exists and contains a significant content of low activity clays? a. a Mollisols in Central Brazil b. an Ultisol in the Congo River basin in Africa c. an Inceptisol in Mississippi d. an Alfisol in New York e. an Oxisol in Minnesota
b
Which of the following is not a major factor in determining the soil aeration status? a. redox potential b. nitrogen gas c. oxygen d. volume of macropores e. carbon dioxide
b
Which of the following is not a secondary mineral? a. gibbsite b. hornblende c. calcite d. silicate clay
b
In which soil orders would recent alluvium most likely be a common parent material?
Entisols
T or F: A pedon is a 3D field unit occupying about 10,000 m^2 of land area
False
T or F: A soil developed in transported parent materials will likely have properties related to the properties of the rock below the C horizon
False
T or F: Alluvial parent materials are those that have been laid down in former lake bottoms
False
T or F: Although the total soil water content of a clay soil is about the same as a nearby well structured silt loam, the clay will likely provide more available water to plants because of its higher volume of small pores
False
T or F: Because soil development is just beginning in Entisols, these soils are generally less variable in properties than are those in the Andisol or Utisol orders
False
T or F: Epipedons are diagnostic subsoil hoizons that are one of the primary means of classifying soils in the US
False
T or F: Even if all the glaciers present today in the world were to melt, the melt water would have no measurable effect on the level of the world's oceans
False
T or F: Glacial till can be recognized by the distinct layering of different kinds of particles
False
T or F: Glacial till is laid down by melt waters gushing out from the front of glaciers
False
T or F: Hysteresis is the phenomenon whereby a soil has the same water content/potential relatoinship when it is being dried as when it is being wetted
False
T or F: In most B horizons one of the dominant processes of soil formation has been eluviation
False
T or F: Iron and aluminum oxides are major components of igneous rocks
False
T or F: Nomenclature of Soil Taxonomy is characterized by the following statement: The names give a clear indication of the modes of genesis of the soil
False
T or F: Plant roots gain access to soil water primarily by the growth of the roots into moist soil
False
T or F: Respiration by plant and animal cells along with photosynthesis releases oxygen and consumes carbon dioxede
False
T or F: Sandstones are good examples of metamorphic rocks
False
T or F: Soils classified as Inceptisols have the least well developed profiles of those in any order in the soil taxonomy system
False
T or F: Soils developed in the wind-blown parent materials such as loess are generally of little agricultural value
False
T or F: Soils in the Oxisols order are deeply weathered and have deep subsurface horizons of calcium oxide
False
T or F: Spodosols are generally less acidic and less sandy than are Alfisols
False
T or F: Sprinkle irrigation is generally more efficient in the use of water than drip irrigation, especially for high valued crops
False
T or F: The C horizons are generally more completely weathered than the other horizons
False
T or F: The H end of a water molecule is attracted to positively charged cations such as Na+ and Ca2+
False
T or F: The parent materials for most coastal plain soils are residual in nature
False
T or F: The property of cohesion in water stems from the attraction of water molecules for soil solids
False
T or F: The topmost horizon in most humid region forest soils is the A horizon
False
T or F: The water potential in soils is generally considered lower than that in the atmosphere
False
T or F: Vapor loss from a south-facing slope in Australia would likely be higher than from a north-facing slope
False
T or F: Weathering of rocks usually is most intense in the center of a rock fragment, and gradually decreases toward the outside
False
The tenacity with which water is held in soils is directly related to the soil moisture content, the higher the moisture level the greater the attraction of the water to the soil
False
T or F: The categories of Soil Taxonomy can be listed from the broadest to the most specific as : order, suborder, great group, subgroup, series, family
False: order, suborder, great group, subgroup, family, series
Which mineral is most resistant to weathering under humid temperate conditions?
Gibbsite
In which of the following "forms" of soil water are pesticides, excess plant nutrients and waste chemicals most apt to move through soils
Gravitational
If soils are to be used for crop production, for which soil order would land drainage be most critical?
Histosols
Which of the following is not a secondary mineral? Gibbsite, calcite, hornblende, silicate clay
Hornblende
Granite is what type of rock?
Igneous
What are the three types of rocks?
Igneous, Sedimentary, Metamorphic
The element most often involved in oxidation reactions as minerals weather is ___
Iron
Which of the following locations in the US would have the highest evaporation from the soil surface in July?
Irrigated cotton field in arizona
Soil temps under an organic mulch will be higher or lower than that or bare soils in the summer but the opposite than that of bare soils in the winter
Lower
Residual parent materials are:
Materials formed by weathering of rocks and minerals in place
Do tropical forests protect the soils from weathering?
NO
Which of the following is not a major factor in determining the soil aeration status
Nitrogen gas
Which of the following will increase the evaporation from the soil surface?
None of the above
Organic matter accumulation is most pronounced in the
O horizon
Which of the following subsurface diagnostic horizons would you expect to find in a highly weathered soil of the humid tropics
Oxic
The transformation of gneiss into smaller mica, quartz, and feldspar pieces is an example of
Physical Weathering
Which of the following actions would best assure good aeration in a soil?
Remove excess water
Which of the following statements concerning applicatoins or capabilities of soil moisture measuring devices is true for the use of a drying oven and balance?
Requires "destructive sampling" for each measurement
Plant roots obtain access to soil water in which of the following ways?
Roots extend into moist soil area & Water flows to the roots by capillarity
The map units of a detailed soil map on Web Soil Survey are most likely to be labeled with names from which category of Soil Taxonomy?
Series
Have Lacustrine parent materials been subjected to weathering for shorter or longer periods of time than residual parent materials near by?
Shorter
Soils in this order are commonly sandy in texture, quite acidic and develop primarily under coniferous trees in cool to cold climates
Spodosols
What causes exfoliation?
Temperature
T or F: A polypedon or individual soil is a group of closely related pedons that conceptually approximates what in the US is called a soil series
True
T or F: A soil developed in residual parent materials will likely have properties related to the properties of the rock below the C horizon
True
T or F: A soil on the south facing slope in Canada is likely to be drier and warmer than a comparable soil on a north facing slope
True
T or F: An aquic soil moisture regime connotes a higher degree of soil moisture saturation than an ustic one
True
T or F: An argillic horizon is a diagnostic horizon characterized by the subsurface accumulation of silicate clays
True
T or F: Andisols are found mostly near recently active volcanoes
True
T or F: Animals, insects and worms affect soil formation primarily by mixing the soil, which increases the porespace where air and water move
True
T or F: Chemical weathering is accelerated by water, oxygen, and organic and inorganic acids moving down through the regolith
True
T or F: Climate influences not only the rate of weathering but the type of native vegetation dominant in an area
True
T or F: Conservation tillage is not practical in some areasw of the Northern part of the US because the practice lowers the surface soil temp in the spring of the year
True
T or F: Early snowfall that arrives before the cold winter weather has frozen the soil generally increases the penetration of water into the soild
True
T or F: Eluviation of clay, iron, and other materials is the principal process responsible for the formation of an E horizon
True
T or F: Evapotranspiration includes vapor losses both from the soil surface and from the leaves of plants
True
T or F: Histosols generally have higher organic matter contents that Mollisols
True
T or F: Hydrolysis involves the splitting of water into its H+ and OH- components while hydration attaches intact water molecules to a compound
True
T or F: Igneous rocks are formed when molten magma cools and solidifies
True
T or F: Marine sediments are typical parent materials in coastal plain areas
True
T or F: Minerals containing iron are generally more resistant to chemical breakdown than minerals that contain Calcium Carbonate
True
T or F: Mollisols are charcterized by a deep epipedon that is high in organic matter
True
T or F: Organic deposits are common in areas where water ponds for extended periods of time
True
T or F: Organic matter distribution in the soil is a significant criterion for differentiating epipedons
True
T or F: Oxisols are more highly weathered that are the soils of any other order
True
T or F: Residual parent materials have formed in place and have not been transported from one area to another
True
T or F: Residual parent materials have generally been subjected to weathering for a longer period of time than have lacustrine or alluvial parent materials
True
T or F: Russian scientists were the first to develop the concept of soils as natural bodies
True
T or F: Sapric and fibric are terms used to describe peat parent materials
True
T or F: Secondary minerals are recrystallized products of the chemical breakdown an/or alteration of primary minerals
True
T or F: Soil and crop management generally has a greater influence on evaporation from the soil surface (E) than on transpiration (T) from leaf surfaces.
True
T or F: The A horizons are more apt to be cultivated than the E horizons
True
T or F: The O horizons of a soil are dominantly organic horizons occurring above mineral horizons
True
T or F: The broadest category of classification in Soil Taxonomy specifies 12 soil orders
True
T or F: The family category focuses on properties affecting plant roots and suitability for engineering uses of soils
True
T or F: The leaf are index significantly affects the solar radiation reaching the soil surface
True
T or F: The matric potential is due to the attraction of water molecules to soil solid surfaces
True
T or F: The most important management factors influencing soil aeration in well-drained soils are those that determine the volume of the soil's macropores.
True
T or F: The name of a subgroup indicates the order, suborder, and great group of which it is a member
True
T or F: The partial pressure (concentration of CO_2) in the soil pores is higher than the partial pressure of this gas in the atmosphere.
True
T or F: The polarity of water helps account for the attraction of water molecules for each other
True
T or F: Vertisols are characterized by high contents of swelling-type clays
True
T or F: Water molecules have polarity because the electrons are not uniformly shared between the two H atoms and one O atom
True
T or F: Water will move from one site in a soil with a higher water potential to an adjacent site with a lower water potential
True
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?
Udoll (MollisOL)
Which of the following describes a soil that likely exists and contains a significant content of low activity clays?
Ultisol in the Congo River Basin in Africa
Which of the following statements concerning applications or capabilities of soil moisture measuring devices is (are) true for the electrical resistance block?
Used to turn on irrigation when soil moisture potential reaches -200kPa
"Biotite --> clay --> iron oxide" represents a
Weathering sequence
"Biotite --> clay --> iron oxide" represents a ________. a. weathering sequence b. catena c. toposequence d. both A and B e. none of the above
a
A 2:1 clay is more active in soil than sand because the clay has _____. Select one: a. negative charge b. less surface area c. less isomorphous charge d. all of the above
a
A grass cover crop grown on cropland over the winter season in a humid temperate region can be expected to ________. Select one: a. reduce the amount of nutrients leached to the groundwater b. significantly reduce the amount of nitrogen fertilizer that will be needed to grow the following crop c. significantly reduce the amount of water percolating to the water table d. increase nutrient concentrations in runoff water e. all of the above
a
A well drained soil under a rain forest in Brazil contains significant amounts of a silicate clay. Which of the following is it most apt to be? Select one: a. kaolinite b. smectite c. chlorite d. fine-grained mica e. vermiculite
a
An acid soil is known to contain toxic quantities of a certain plant nutrient. Which of these essential elements is it most likely to be? Select one: a. manganese b. nitrogen c. molybdenum d. phosphorus e. boron
a
Compared to the same soil used for cropland, a forested soil would be expected to lose ________ total P to streams draining the watershed. Select one: a. less b. about the same amount of c. more
a
Which of the following locations in the United States would have the highest evaporation (E) from the soil surface in July? a. a forest woodland in Illinois b. an irrigated cotton field in Arizona c. a corn field in New York d. an unirrigated soil in South Carolina growing cotton e. a bare, unirrigated dry land soil in Colorado
b
Which of the following micronutrients is least commonly found to be deficient in plants? Select one: a. copper b. chlorine c. iron d. boron e. manganese
b
Which of the following nutrient elements is usually present in the soil solution as a simple cation? Select one: a. B b. Zn c. Mo d. Cl e. all of the above
b
Which of the following pH values represents the most acid condition? a. 7.0 b. 1.0 c. 100 d. 5.55 e. 10.0
b
Which of the following sources of water have the shortest average residence time? a. oceans and ice caps b. clouds c. soil moisture d. groundwater
b
Concentrated animal production as is practiced in modern industrial agriculture usually results in ________. Select one: a. nutrient excesses in the area of the livestock operation b. depletion of nutrients from the soils in the vicinity c. insufficient manure production to properly fertilize cropland on the livestock farm d. nutrient exports from the operation that exceed imports e. both C and D
a
Fertilization to supply the nutrient element nitrogen is often accomplished by which type of application? Select one: a. injection of a gas into the soil b. broadcast of a chloride salt c. application of a chelate to the soil d. incorporation of powdered limestone rock e. broadcast of the nearly pure element as a solid
a
Fertilization to supply the nutrient element potassium is often accomplished by which type of application? Select one: a. broadcast of a chloride salt b. injection of a gas into the soil c. incorporation of powdered limestone rock d. application of a chelate to the soil e. broadcast of the nearly pure element as a solid
a
How does the amount of lime needed to neutralize the residual acidity in a clay loam soil compare to that needed to neutralize the active acidity in that soil? Select one: a. residual requires 5,000 times greater b. residual requires about the same c. residual requires 10 times greater d. residual requires about double e. residual requires considerably less
a
Humus is an important soil colloid. It differs from 2:1 type minerals in all but one of the following characteristics: Select one: a. capable of adsorbing cations b. influence on soil aggregate stability c. influence of isomorphous substitution d. structural framework of the particles e. CEC dependence on soil pH
a
If you want to quickly (in just a few days) increase the pH of a soil from 5.5 to 7.0, which of the following would you use? Select one: a. burned lime (calcium oxide) b. ammonium nitrate c. sawdust d. calcitic limestone e. dolomitic limestone
a
Which of the following statements is true? a. Rill erosion is initiated before water concentrates in small 1-2 cm channels. b. Rill erosion channels can be removed by ordinary cultivation. c. Gully erosion carries the most sediment away from lands in the United States. d. Sheet erosion is most obvious from a distance. e. Rill erosion is the most serious in forested areas.
b
You are seeking a soil with high clay content but one that is not sticky when wet nor hard and cloddy when dry. In which of the following suborders would you most likely find this soil? a. Cambids b. Ustox c. Aquands d. Udert
b
In explaining erosion processes to a friend, which of the following would you say about accelerated erosion? a. It is greatly enhanced by the splash effect of raindrops impacting bare soil. b. It is increasing in intensity in the United States, especially in the past 10 years. c. It involves a much less rapid process than geological erosion. d. It removes more nitrogen from the surface soil than calcium. e. It refers to sediment carried by water flowing at ever greater velocity.
a
Land drainage is beneficial because ________. a. it increases the depth of root penetration in the soil b. it increases the alternate of expansion and contraction due to freezing and thawing of soils c. it increases the availability of iron and manganese in acid soils d. it increases the water-to-air ratio in the soil pores e. it slows down the rate of soil warming in the spring
a
Secondary minerals are most prominent in the ________ fraction of soils. a. clay b. sand c. silt d. organic
a
Soil colors are scientifically described by ________ color designations such as 10YR3/4. a. Munsell b. USDA c. structural d. wavelength e. Parson's
a
This diagnostic horizon would likely not restrict root growth in soils
Albic
Which soil moisture regime has the highest soil moisture levels?
Aquic
The osmotic potential would likely be lowest in soils of which of the following orders
Aridisols
Soil tilth refers to ________. a. the physical suitability of a soil for plant growth b. ratio of bulk density to particle density c. the moisture content at which a soil is best suited for tillage d. micro-aggregates produced as a by-product of tillage e. the bearing strength of a soil under a given downward force
a
Soils in which of the following soil suborders would most likely have a prominent E horizon under the A horizon? a. Udalfs b. Aquepts c. Udolls d. Orthents
a
In which horizon has the process of illuviation most likely occurred?
B horizon
Silicate clay accumulation is most common in the
B horizon
The electronegative charge on 2:1 type silicate clays is due primarily to ________. a. Substitution of one metallic atom for another in the crystal structure of the clay b. the preponderance of tetrahedral sheets compared to octahedral sheets c. extremely small size of the individual colloid particles d. the effect of pH on the presence of H+ ions in the exchange complex e. ionization of surface OH groups
a
The key to preventing soil erosion by water on both farmland and landscaping job sites is ________. a. to keep the soil surface covered with vegetation b. to keep the soil moist (with irrigation if necessary) c. to practice good landscape sanitation by clearing away any weeds and old plant residues d. to provide adequate surface and subsurface drainage e. to grade or till the soil until a smooth surface is achieved
a
The opposite process from mineralization is ________. Select one: a. immobilization b. nitrification c. ammonification d. denitrification e. none of the above
a
The osmotic potential would likely be lowest in soils of which of the following orders? a. Aridisols b. Spodosols c. Ultisols d. Histosols e. Oxisols
a
The process of ________ releases soluble nitrogen as the result of the breakdown of nitrogen-rich organic compounds. Select one: a. mineralization b. denitrification c. nitrification d. volatilization e. symbiosis
a
The reaction: mica + H2O → K+ + OH- + acid clay is an example of ________. a. chemical weathering b. physical weathering c. exfoliation d. carbonation e. both A and C
a
To be practical, a nitrification inhibitor should kill or inhibit ________. Select one: a. Nitrosomonas b. Nitrobacter c. either A or B d. none of the above
a
To be practical, a nitrification inhibitor should kill or inhibit ________. Select one: a. Nitrosomonas b. Nitrobacter c. either A or B d. none of the above
a
Urban development of land that was previously natural vegetation or farm land usually greatly ________ soil infiltration capacity and therefore greatly increases ________. a. decreases; stream bank erosion. b. increases; groundwater recharge. c. decreases; groundwater recharge. d. increases; stream bank erosion
a
Where high-value crops or individual ornamental shrubs are to be grown and water is expensive, the most efficient type of irrigation to use would be ________. a. drip or trickle b. furrow c. center pivot d. basin flooding
a
Which ion is most weakly attracted to soil colloids? Select one: a. Chloride b. Sodium c. Calcium d. Hydrogen
a
Which of the following best characterizes the field capacity of a soil? a. water content of a soil 24 hours after a saturating rain b. a wetted soil prior to the removal of the gravitational water c. the total water in the soil micropores d. maximum water content of a soil
a
Which of the following means of estimating soil water levels gives a direct measurement of the water content? a. gravimetric determinations b. pressure membrane c. gypsum blocks d. neutron scattering e. tensiometer
a
Which of the following processes are most apt to encourage good soil aeration? a. creation of more macropores b. diffusion of oxygen from the soil to the atmosphere c. root respiration d. reaction of oxygen with organic matter e. organic matter decomposition
a
Which of the following statements concerning applications or capabilities of soil moisture measuring devices is (are) true for the use of a drying oven and balance? a. requires "destructive sampling" for each measurement b. used to turn on irrigation when soil moisture potential reaches -20.0 kPa c. good to turn on automatic irrigation at -5.0 kPa d. is an indirect measurement of soil water
a
Which of the following subsurface diagnostic horizons would you expect to find in a highly weathered soil of the humid tropics? a. oxic b. salic c. spodic d. natric e. cambic
a
Which soil moisture regime has the highest soil moisture levels? a. aquic b. udic c. aridic d. xeric e. ustic
a
If you wanted to find a soil where physical weathering dominated over chemical breakdown you would be most apt to find it in _____
a desert region of Arizona
The presence of rocks such as shale and sandstone indicate the existence of
ancient seas
A soil with a bulk density equal to 0.35 Mg/m3 is most likely what type of soil? a. a well-structured garden soil b. a peat soil c. an Ultisol d. a Vertisol e. a compacted urban soil
b
Among the soils of which order would you most likely find the highest buffering capacities? Select one: a. Alfisols b. Vertisols c. Ultisols d. Oxisols e. Spodosols
b
Biomass consists of ________. a. identifiable biomolecules b. living organisms and cells c. dead tissues and wastes d. polymerized, non-identifiable molecules e. all of the above
b
Compared to silt, clay-sized soil particles are characterized by ________. a. less capacity to hold nutrients in plant-available forms b. greater attraction for water c. greater proportion of primary minerals d. less tendency to form hard clods when dry
b
In soils of which great group would you most likely find wide surface cracks during periods of dry weather?
Calciusters (ERT for the vertisol)
The process of aerobic respiration is a significant source of which of the following gases?
Carbon Dioxide
Mica + H2O --> K(+) + OH(-) + acid clay is an example of
Chemical weathering
Secondary minerals are most prominent in the _______ fraction of soils
Clay
Five major factors influencing soil formation
Climate, Bioorganisms, topography, parent material, time
Mixed angular gravel, rock, and soil found at the foot of a slope is typically of what type of parent material?
Colluvial
Soil in this suborder would be more likely to occur in Minnesota than in Texas.
Cryolls
Glacial till is a term used to describe parent materials that ________. a. were transported by water gushing from glacial fronts. b. contain a heterogeneous mixture of mineral debris dropped by receding glaciers. c. were laid down in the bottom of former glacial lakes. d. were transported by high winds during glacial periods. e. are sorted by rapidly flowing melt waters.
b
Hydroxyl ion concentrations are greatest in a soil solution with a pH value of ________. a. 0.1 b. 6.5 c. 5.0 d. 4.0
b
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. the water table c. field capacity d. the liquid limit e. the percolation rate
b
If you want to maximize the quantity of vegetative cover on soil which of the following tillage practices would you use? a. stubble mulch b. no-tillage c. strip till d. ridge tillage e. conventional moldboard plow
b
In a soil at pH 5.0, most of the inorganic P is likely to be in the form of ________. Select one: a. tricalcium phosphates b. hydrous iron and aluminum phosphates c. monocalcium phosphates d. phospholipids e. hydroxy apatites
b
In the early stages of plant nitrogen deficiency, the most obvious symptoms are ________. Select one: a. brown edges on leaves scattered randomly all over the plant b. yellowish colors in the oldest leaves c. purpling of the youngest leaves d. brown spots and tiny holes on the underside of most leaves e. yellowing of the youngest leaves
b
In which of the following horizons has the process of illuviation most likely occurred? a. E horizon b. B horizon c. A horizon d. O horizon e. C horizon
b
Perforation placement is usually used to fertilize ________. Select one: a. row crops b. landscape trees c. turfgrass d. forests
b
Practices that add organic matter and reduce tillage can be expected to most significantly increase the ________ in a soil. a. bulk density b. porosity c. fineness of texture d. sand content
b
A landscaping contractor wants to change the texture of a silt loam soil to meet the specifications for a loam. S/he would most likely do so by adding ________ to the soil and mixing it well. a. humus b. compost c. sand d. clay e. either A or B
c
A soil has been managed using a no-till system for 10 years following many years of conventional tillage operations. Which of the following changes in surface soil properties would you expect due to the no-till management system? a. bulk density would increase b. the earthworm population would decline c. organic matter content would increase d. aggregate stability would decline e. soil pH would increase
c
A soil has been managed using a no-till system for 10 years following many years of conventional tillage operations. Which of the following changes in surface soil properties would you expect due to the no-till management system? a. the earthworm population would decline b. bulk density would increase c. organic matter content would increase d. soil pH would increase e. aggregate stability would decline
c
Alternate freezing and thawing of soils results in the "heaving" of plants and the destruction of shallow building foundations. This effect is due primarily to ________. a. the breaking down of soil aggregates due to freezing and thawing b. the wetting and drying of swelling-type clays c. the expansion of water when it freezes d. the hydration of adsorbed cations on the soil colloids e. pressure from upward movement of water from lower horizons
c
Ammonium fixation would be expected to be greatest in soils containing a lot of ________. Select one: a. Frankia b. Rhizobium bacteria c. vermiculite d. iron oxides
c
Argillic horizons are characterized by ________. a. high levels of iron and aluminum oxides b. high level of Na+ ions c. accumulation of silicate clays d. impervious hardpan layers e. organic matter accumulation
c
Because of ________, soils developed in marine marshes can become extremely acid if drained for agriculture or used as topsoil. Select one: a. oxidation of sulfates b. reduction of elemental sulfur c. oxidation of sulfides d. reduction of sulfates e. all of the above
c
Capillarity in soils ________. a. is not involved in the process of water uptake from soils b. does not account for unsaturated water movement in soils c. involves both adhesion and cohesion d. is enhanced by the symmetrical nature of the water molecule e. is independent of the matric potential in soils
c
Compared to gypsum, elemental sulfur is sometimes considered a more desirable fertilizer material because ________ Select one: a. it is less dependent on warm, moist conditions for availability b. it causes less soil acidity than gypsum c. it contains more nutrient sulfur, kilogram for kilogram, than gypsum d. plants respond to sulfur more rapidly e. all of the above
c
Fertilization to supply the nutrient element sulfur is often accomplished by which type of application? Select one: a. broadcast of a chloride salt b. incorporation of powdered limestone rock c. broadcast of the nearly pure element as a solid d. application of a chelate to the soil e. injection of a gas into the soil
c
If you want to maximize the quantity of vegetative cover on soil which of the following tillage practices would you use? a. strip till b. stubble mulch c. no-tillage d. conventional moldboard plow e. ridge tillage
c
In explaining erosion processes to a friend, which of the following would you say about accelerated erosion? a. It refers to sediment carried by water flowing at ever greater velocity. b. It involves a much less rapid process than geological erosion. c. It is greatly enhanced by the splash effect of raindrops impacting bare soil. d. It removes more nitrogen from the surface soil than calcium. e. It is increasing in intensity in the United States, especially in the past 10 years.
c
In recent years, a soil test for nitrogen has been developed and widely used in humid regions in predicting how much nitrogen will need to be applied to supplement natural mineralization in the soil. This test is called the ________. Select one: a. soil nitrogen partial analysis (SNPA) b. Differential Nitrate Extraction Test (DNET) c. pre-sidedress nitrate test (PSNT) d. Mehlich II nitrogen test e. diagnosis and recommendation integrated system (DRIS)
c
In soils of which great group would you most likely find wide surface cracks during periods of dry weather? a. Argiaquolls b. Albaqualfs c. Calciusterts d. Kandiaquults e. Haplustox
c
In which of the following "forms" of soil water are pesticides, excess plant nutrients and waste chemicals most apt to move through soils? a. available b. unsaturated c. gravitational d. hygroscopic e. capillary
c
Mechanical weathering processes result in ________. a. the hydrolysis of minerals through frost action b. the oxidation of iron and manganese compounds c. the disintegration of rocks due to differential expansion of minerals d. the decomposition of primary minerals
c
Methemoglobinemia is principally a potential threat to ________. Select one: a. adults drinking water high in nitrate b. adults drinking water high in sulfate c. babies drinking water high in nitrate d. babies drinking water high in sulfate e. all of the above
c
Nutrient uptake by plants acidifies soils because roots _____. Select one: a. absorb acids and desorb bases b. increase base saturation c. absorb basic cations and desorb hydrogen d. release sodium into the soil
c
Organisms which use carbon dioxide or carbonates for their carbon source and either sunlight or inorganic chemicals for their energy source are called ________. a. heterotrophs b. detritivores c. autotrophs d. facultative anaerobes e. actinomycetes
c
Silicate clay accumulation is most common in the ________. a. C horizon b. O Horizon c. B horizon d. E horizon e. A horizon
c
Soil occupies the ________ part of the regolith. a. lower b. younger c. upper d. Both B and C
c
Soils high in organic matter commonly hold more plant-available water than comparable soils with lower organic matter levels. This is most likely due to what characteristics of the high O.M. soils? a. larger micro pore space b. higher clay content c. higher field capacity d. lower permanent wilting percentage
c
Some soil colloids exhibit positive charges under highly acid conditions. To what are these charges likely due? Select one: a. increase in the level of H+ ions on the exchange complex b. the adsorption of Al3+ ions on the colloid c. protonation of some hydroxy groups by excess H+ ions d. substitution of lower valent atoms for higher valent atoms in the octahedral sheet e. the release of some OH- ions leaving an unsatisfied positive charge on the colloid
c
The P factor in the Universal soil-loss equation is concerned with all but one of the following: a. contour tillage b. vegetative covers c. soil erodibility d. strip-cropping e. terraces
c
The P factor in the Universal soil-loss equation is concerned with all but one of the following: a. vegetative covers b. strip-cropping c. soil erodibility d. contour tillage e. terraces
c
The bulk of gaseous interchange in soils takes place by ________. a. respiration b. mass flow c. diffusion d. dissolution in water e. partial pressure of N2
c
The likelihood of polluting groundwater with pesticides and plant nutrients is enhanced by ________. a. light tillage of the upper centimeter or so of soil b. the production of oats rather than wheat c. the presence of macropores in the soil d. conventional tillage as a choice compared with conservation tillage Incorrect e. the use of tillage to control weeds
c
The lithosphere is made up of ________. a. air b. water c. rock d. plants and animals e. all of the above
c
The map units on a detailed soil map on Web Soil Survey are most likely to be labeled with names from which category of Soil Taxonomy? a. great group b. suborder c. series d. subgroup e. order
c
The matric potential of soil water is ________. a. is little affected by soil solids b. influenced greatly by the content of salts in the soil c. not influenced appreciably by the force of gravity d. is generally higher than that of pure water outside the soil
c
The most common form of on-site waste water treatment for homes not hooked up to sewer lines is the ________. a. electrical induction sterilization b. soil enrichment process c. septic tank and drain field d. active composting method e. chemical "flush" system
c
The universal soil-loss equation (USLE) suggests that soil erosion loss is a product of all but one of the following factors: a. climate b. sloped steepness c. soil drainage d. slope length e. vegetative cover
c
The universal soil-loss equation (USLE) suggests that soil erosion loss is a product of all but one of the following factors: a. sloped steepness b. slope length c. soil drainage d. vegetative cover e. climate
c
The use of sedimentation to separate sand, silt, and slay depends upon the fact that smaller particles ________. a. settle more rapidly b. are less dense c. settle more slowly d. are more dense
c
Wetlands and forests growing along the banks of rivers remove much nitrogen from groundwater by the process of ________. Select one: a. nitrification b. immobilization c. denitrification d. ammonification e. none of the above
c
Which micronutrient element is found in the greatest quantity in most soils? Select one: a. Zn b. Cu c. Fe d. B e. Mn
c
Which micronutrient is particularly critical for legume plants because of its place in the nitrogenase enzyme that allows Rhizobia-infected legumes to utilize atmospheric nitrogen? Select one: a. B b. Mn c. Mo d. Zn e. Cu
c
Which of the following actions would best assure good aeration in a soil? a. use cover crops, especially legumes b. use a plastic mulch c. remove excess water d. increase the soil temperature e. add organic residues
c
Which of the following diagnostic horizons would likely not restrict root growth in soils? a. salic b. placic c. albic d. petrocalcic e. fragipan
c
Which of the following is not a characteristic of soil colloids? Select one: a. electronegative charges b. ability to exchange ions with the soil solution c. low water holding capacity d. high external surfaces e. very small size
c
Which of the following pH values represents a neutral condition? a. 1.0 b. 10.0 c. 7.0 d. 6.0 e. 10
c
Which of the following statements is correct? a. Limestone parent materials enhance the process of acidification. b. Calcium carbonate accumulation is more prominent in humid than in arid regions. c. Lacustrine parent materials have been subject to weathering for shorter periods of time than residual parent materials nearby. d. Nutrient cycling in forested areas contributes little to soil formation. e. Soils on hillsides tend to be deeper than those on level lands.
c
Which of these compounds does not complex with phosphorus and make it less available for plant uptake? Select one: a. Calcium b. Iron c. Sodium d. Aluminum
c
Glacial till is a term used to describe parent materials that
contain a heterogeneous mixture of mineral debris dropped by receding glaciers
"Subsoil" is generally equivalent to which soil horizon? a. A b. E c. D d. B e. C
d
A cover crop is usually grown for the purpose of ________. Select one: a. improving soil physical properties b. saving or recycling nutrients c. covering expenses for pollution control measures d. both A and B e. all of the above
d
A homeowner in New Mexico attempted to grow azaleas in a well drained soil (pH 7.5) but the plants were stunted and the leaves were yellow. What is the most likely cause of this constraint? Select one: a. Na toxicity b. P deficiency c. Mn toxicity d. Fe deficiency e. Ca toxicity
d
A soil profile consists of ________. a. the sum of chemical and physical data known about a soil b. the general outline of a soil when viewed from above c. the spatial boundaries of a particular soil d. the set of layers seen in a vertical cross Section of a soil Correct e. the way a soil "feels"
d
A sticky, putty-like feel indicates a high percentage of which soil separate? a. silt b. humus c. sand d. clay e. none of the above
d
A wildlife biologist in South Africa notes that the soils on south-facing slopes are wetter and deeper than those on north-facing slopes, and therefore support more wildlife. What likely accounts for this difference? a. more rapid plant growth on the south slopes b. more solar radiation on the south slopes c. sandier soils on the north slopes d. higher soil temperatures on the north slopes e. differences in rainfall from one area to another
d
Ammonia losses are likely to be greatest if a nitrogen source is placed about 10 cm deep in ________. Select one: a. an acid, clay loam soil b. an acid, sandy loam soil c. a calcareous clay loam soil d. a calcareous sandy loam soil
d
As biotite weathers in soils, which of the following would not likely develop by mere alteration of this mineral? Select one: a. smectite b. vermiculite c. chlorite d. kaolinite e. fine-grained mica
d
Available phosphorus levels are constrained in alkaline and salt-affected soils because of ________. Select one: a. high manganese levels b. high iron and aluminum levels c. high exchangeable sodium levels d. high calcium and magnesium levels e. low hydrogen ion levels
d
Brown and red colors in subsurface horizons are caused by ________ in the soil. a. manganese b. organic matter c. aluminum oxides d. iron oxides
d
Compared to land that is not disturbed by tillage, conventionally plowed cropland usually loses much more ________. Select one: a. dissolved P b. total P c. particulate P d. both B and C are correct e. none of the above is correct
d
If you wanted to find a soil where physical weathering dominated over chemical breakdown you would be most apt to find it in ________. a. the hill lands of Georgia b. a coastal plain area of Delaware c. a humid region in Brazil d. a desert region of Arizona e. a lacustrine deposit in Minnesota
d
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? Select one: a. humus b. chlorite c. kaolinite d. montmorillonite e. fine-grained mica
d
In acid soils the principal chemical form of potassium available for plant uptake is ________. Select one: a. P- b. HKO22- c. K2O d. K+ e. H2KO2-
d
In order for nitrate to form from soil organic matter, ________ must be present in the soil Select one: a. Nitrosomonas b. Nitrobacter c. either A or B d. both A and B e. none of the above
d
In what range of soil pH is phosphorus generally most available to plants? Select one: a. 7.0-8.0 b. 4.5-5.5 c. 3.5-4.5 d. 5.5-7.0 e. >8.0
d
Loss of P to groundwater is likely to be most significant for which type of soil? Select one: a. highly weathered tropical soils b. calcareous soils c. sandy soils under pine forests (Spodosols) d. cultivated organic peat soils e. silt loam soils formed in windblown loess
d
Most of the different nutrients essential for growth are supplied to plants directly from the ________. a. cosmic radiation b. humus c. rain water d. soil solution e. atmosphere
d
Non-point source losses of which element are considered to be a serious water pollution problem because the resulting high concentration of the element in stream water is toxic to most fish. Select one: a. phosphorus b. potassium c. both A and B d. neither A nor B
d
Of the macronutrients, which can be most correctly said to be a renewable resource? Select one: a. potassium b. calcium c. phosphorus d. nitrogen e. iron
d
Plants obtain nitrogen from the soil by taking up ________. Select one: a. soluble anions b. soluble organic compounds c. soluble cations d. all of the above e. none of the above
d
Sodic soils generally have a poor physical condition. To what is this most likely due? Select one: a. low organic matter content b. precipitation of the Ca2+ and Mg2+ ions as carbonates c. impact of raindrops on the soil surface d. dispersal of the Na saturated soil colloids e. high content of smectite in the soils
d
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. Andisols c. Alfisols d. Spodosols e. Ultisols
d
Soils in which of the following suborders would be more likely to occur in Minnesota than in Texas? a. Cambids b. Udalfs c. Usterts d. Cryolls e. Fluvents
d
Texture describes the ________ of particles in a soil. a. arrangement b. mineralogical makeup c. roughness d. sizes e. colors
d
The drainage of certain wetlands has resulted in extreme soil acidity. This is due primarily to which of the following processes that take place when the soil is drained? Select one: a. high redox potential characteristic of aerated soils b. oxidation of organic materials to produce organic acids c. release of nitric acid due to oxidation of nitrogen compounds d. oxidation of sulfur-bearing minerals that produces sulfuric acid e. reduction of iron to low valent states that stimulate acidity
d
The evapotranspiration (ET) from a pine forest was found to be 50 cm during a growing season. If the evaporation from the soil surface during this period of time was 5 cm, what is the level of loss from leaf surfaces? a. 50.0 cm b. Impossible to calculate from the data given c. 10 cm d. 45 cm e. 55 cm
d
The exchange complexes of strongly acid (pH 4.5) mineral soils are saturated mainly with ________. a. exchangeable Al(OH2)+ ions b. tightly bound Al3+ ions c. tightly bound H+ ions d. exchangeable Al3+ ions e. exchangeable H+ ions
d
The following are characteristics of a water molecule. a. It is held in soils by adhesion but not adsorption. b. It is attracted to surfaces with negative but not positive charges. c. The H to O to H angle is approximately 90°C. d. It has a positive and a negative side.
d
The key to preventing soil erosion by water on both farmland and landscaping job sites is ________. a. to practice good landscape sanitation by clearing away any weeds and old plant residues b. to provide adequate surface and subsurface drainage c. to keep the soil moist (with irrigation if necessary) d. to keep the soil surface covered with vegetation e. to grade or till the soil until a smooth surface is achieved
d
The process of aerobic respiration is a significant source of which of the following gases? a. ammonia b. nitrogen c. oxygen d. carbon dioxide e. methane
d
The redox potential is a measure of ________. a. molecular oxygen content b. carbon dioxide content c. the ferric ion content d. the tendency of a substance to accept or donate electrons e. the balance between hydrogen and hydroxyl ions in solution
d
The redox potential is a measure of ________. a. the balance between hydrogen and hydroxyl ions in solution b. molecular oxygen content c. carbon dioxide content d. the tendency of a substance to accept or donate electrons e. the ferric ion content
d
The swelling/shrinking tendency of some silicate clay minerals is due primarily to ________. Select one: a. the high Mg2+ contents in the octahedral layers 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+ d. the movement of water molecules in and out of the interlayers of the crystal e. varying thickness of the film of water covering the external surface of the particles
d
The water in the soil typically differs from pure water because the soil water ________. a. contains mineral nutrients b. contains organic compounds c. is restrained in its flow by attraction to particle surfaces d. all of the above e. none of the above
d
To monitor the effects of management on soil fertility, it is best to sample the soils in an area ________. Select one: a. every one to three years b. from the same depth every time c. at the same season every time d. all of the above e. none of the above
d
Which of the following best characterizes the field capacity of a soil? a. a wetted soil prior to the removal of the gravitational water b. the total water in the soil micropores c. maximum water content of a soil Incorrect d. water content of a soil 24 hours after a saturating rain
d
Which of the following statements concerning applications or capabilities of soil moisture measuring devices is (are) true for the electrical resistance block? a. would give the same reading for both a loamy sand and a silt loam if both contained 15% moisture b. good to turn on automatic irrigation at -50 kPa c. requires "destructive sampling" for each measurement d. used to turn on irrigation when soil moisture potential reaches -200 kPa e. both A and D
d
Which of the following will not increase the efficiency of water use by plants in an irrigation system? a. the use of concrete-lined delivery ditches b. the use of crop residues to reduce evaporation c. the use of drip irrigation for fruit trees d. the use of flood irrigation for forage crops e. the use of herbicides to control weeds
d
Wind erosion is generally not affected by ________. a. soil texture b. soil moisture c. bulk density of the soil d. soil pH e. soil crusting
d
You are working with a soil colloid known to have a reasonably high potassium level, a cation exchange capacity of about 20 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? Select one: a. smectite b. kaolinite c. humus d. fine-grained mica e. vermiculite
d
In which of the following epipedons is the organic matter level generally lowest? a. umbric b. mollic c. melanic d. histic e. ochric
e
Nitrogen is a component of which essential plant compounds? Select one: a. DNA b. chlorophyll c. enzymes d. proteins e. all of the above
e
Plant roots obtain access to soil water in which of the following ways? Select one: a. Water vapor moves from the wet soil areas to the root surfaces. b. Roots extend into moist soil area. c. The roots contract and leave room in the pores for the water to move in. d. Water flows to the roots by capillarity. e. both B and D
e
Soil scientists from which country first conceived the idea that soils were natural bodies? a. France b. Great Britain c. Belgium d. United States e. Russia
e
The amount of P lost from agricultural soils by the process(s) of ________ is generally considerably greater than the corresponding losses of potassium. Select one: a. leaching b. gaseous evolution c. harvest removal d. both B and C are correct e. none of the above are correct
e
The great majority of nitrogen (95 to 98%) in soils can be found in the form of ________. Select one: a. dissolved anions b. dissolved cations c. primary minerals d. secondary minerals e. organic compounds
e
The negative charges associated with smectite clay crystals are due mostly to ________. Select one: a. high pH associated with the formation of the mineral b. OH groups on the external surface of the crystal c. substitution of Si for Al in the tetrahedral sheet d. substitution of Al for Mg in the tetrahedral sheet e. isomorphous substitution of Mg for Al in the octahedral sheet
e
The nutrient element magnesium is often supplied by which type of application? Select one: a. application of a chelate to the soil b. injection of a gas into the soil c. broadcast of the nearly pure element as a solid d. broadcast of a chloride salt e. incorporation of powdered limestone rock
e
The percentages of which soil components represent the minimum information necessary in order to determine the textural class of a soil? a. gravel and sand b. clay and organic matter c. sand, silt and clay d. clay, water and air e. silt and sand
e
Which of the following categories of Soil Taxonomy provides the greatest specificity of soil properties? a. suborder b. order c. great group d. family e. series
e
Which of the following human actions is most apt to result in a long term decrease in soil pH? a. application of NH4- containing fertilizers b. emission of gases from automobiles c. Application of unlimed sewage sludge d. Application of farm manure e. All of the above
e
Which of the following is considered to be a plant macronutrient? a. C b. P c. S d. N e. all of the above
e
Which of the following is not a characteristic of soil colloids? Select one: a. very small size b. electronegative charges c. high external surfaces d. ability to exchange ions with the soil solution e. low water holding capacity
e
Which of the following practices is(are) useful in stabilizing surface soil structure? a. minimizing tillage b. growing grass sod c. use of organic mulches d. use of cover crops e. all of the above
e
Which of the following statements is true? a. Rill erosion is initiated before water concentrates in small 1-2 cm channels. b. Sheet erosion is most obvious from a distance. c. Rill erosion is the most serious in forested areas. d. Gully erosion carries the most sediment away from lands in the United States. e. Rill erosion channels can be removed by ordinary cultivation.
e
Which of the following will increase the evaporation (E) from the soil surface? Select one: a. the use of no-till culture b. adding straw mulch to the soil surface c. plastic mulch d. stubble mulch farming e. none of the above
e
Which of the following will increase the evaporation (E) from the soil surface? a. the use of no-till culture b. adding straw mulch to the soil surface c. plastic mulch d. stubble mulch farming e. none of the above
e
Wind erosion is generally not affected by ________. a. bulk density of the soil b. soil texture c. soil moisture d. soil crusting e. soil pH
e
A pedon is a three-dimensional field unit occupying about 10,000 square meters (1 hectare) of land area. t/f
f
A tetrahedral sheet is characterized by a plane of aluminum atoms surrounded by oxygen and hydroxyl groups. t/f
f
A, B, C, and E horizons can be found in any true soil. t/f
f
All but a few nematodes are pests, attacking either economic or wild plants. t/f
f
Allelopathic chemicals, once added to soil, usually make the affected soil unsuitable for any plant life for periods of years. t/f
f
Although subsoil is more difficult to obtain, it is generally equally as good as topsoil for landscaping purposes. t/f
f
Although the total soil water content of a clay soil is about the same as a nearby well structured silt loam, the clay will likely provide more available water to plants because of its higher volume of small pores. t/f
f
Ammonia volatilization is a process by which much needed nitrogen is added to the pool of plant-available nitrogen in soils. t/f
f
Ammonium fixation occurs to the greatest extent in the O and A horizons. t/f
f
Applying heavy dressings of N fertilizer will tend to produce sugary-sweet fruits and vegetables. t/f
f
Because soil development is just beginning in Entisols, these soils are generally less variable in properties than are those in the Andisol or Ultisol orders. t/f
f
Buffer strips are usually a last-resort mechanism of pollution control because of their expense and unfavorable side-effects. t/f
f
Compared to the rest of the soil, the rhizosphere is kept relatively sterile by the action of plant roots. t/f
f
Earthworms generally are most abundant in sandy, acid soils typically under coniferous forest vegetation. t/f
f
Epipedons are diagnostic subsoil horizons that are one of the primary means of classifying soils in the United States. t/f
f
Eutrophication is enhanced by the presence of pesticides in the water draining from agricultural soils. t/f
f
Even if all the glaciers present today in the world were to melt, the melt water would have no measurable effect on the level of the world's oceans. t/f
f
Except for some kinds of foods, modern industry has made human dependence on soils a thing of the past. t/f
f
For most soils, even if they test "high" in a nutrient such as potassium or nitrogen, it is necessary to apply at least as much of each nutrient as is removed in the harvest, if the soil is not to eventually become infertile and unproductive. t/f
f
Forests in decline because of acid deposition can often be brought back to high productivity with just a few applications of nitrogen fertilizer. t/f
f
Glacial till can be recognized by the distinct layering of different kinds of particles. t/f
f
Glacial till is laid down by melt waters gushing out from the front of glaciers. t/f
f
Humus has a much higher cation adsorption capacity at pH 5.5 than at pH 8.0. t/f
f
Hydraulic conductivity is commonly higher in soils on which conventional tillage systems have been used than where no-tillage systems have been followed. t/f
f
Hydroponics will likely be a key element in enabling the world to feed and clothe its increasing human population in the next few decades. t/f
f
Hysteresis is the phenomenon whereby a soil has the same water content/potential relationship when it is being dried as when it is being wetted. t/f
f
Iron and aluminum oxides are major components of igneous rocks. t/f
f
Iron and manganese are commonly deficient in very acid soils. t/f
f
Kaolinite is most prevalent in soils developed from volcanic ejecta (Andisols). t/f
f
Light colored surface soils are likely to be warmer than dark-colored surface soils if soil moisture and other conditions are the same. t/f
f
Most, if not all, of the nutrient supply stored in a fertile soil is in forms readily available to plants. t/f
f
Mycorrhizae involve a symbiotic combination of certain bacteria and plant cells. t/f
f
Natural soils (as opposed to modern farm soils) can recycle organic compounds, but not inorganic elements. t/f
f
Phosphate availability is constrained in alkaline soils by the presence of iron and aluminum oxides. t/f
f
Plant roots gain access to soil water primarily by the growth of the roots into moist soil. t/f
f
Reduced forms of iron and manganese along with soil organic matter largely control the color of well-drained soils. t/f
f
Removing all the straw with the harvest of paddy rice would increase the amount of methane produced by the paddy soil microorganisms. t/f
f
Research has shown that most herbicides and insecticides used in agriculture drastically reduce the numbers of living meso- and microorganisms in soils for several years after the application of these chemicals. t/f
f
Respiration by plant and animal cells along with photosynthesis releases oxygen and consumes carbon dioxide. t/f
f
Routine soil testing on a regular basis allows landowners to monitor most changes in soil quality. t/f
f
Slope length is generally of greater significance in determining erosion rate than is steepness of slope. t/f
f
Smectite and vermiculite are more prominent in extremely weathered soils than in soils where only modest weathering has occurred. t/f
f
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. t/f
f
Soils classified as Inceptisols have the least well developed profiles of those in any order in the Soil Taxonomy system. t/f
f
Soils in the Oxisols order are deeply weathered and have deep subsurface horizons of calcium oxide. t/f
f
Spodosols are generally less acidic and less sandy than are Alfisols. t/f
f
Sprinkle irrigation is generally more efficient in the use of water than drip irrigation, especially for high valued crops. t/f
f
Subsoil is typically equivalent to the O horizon. t/f
f
Subsoiling is a primitive deep tillage technique that results in extremely high subsoil bulk density. t/f
f
The C horizons are generally more completely weathered than the other horizons. t/f
f
The amount of limestone required to increase the pH from 5 to 7 would likely be higher for an Oxisol than for an Alfisol. t/f
f
The categories of Soil Taxonomy can be listed from the broadest (first) and most specific (last) as: order, suborder, great group, subgroup, series, family. t/f
f
The dark brown and black humus found in many soils does not mix well with clay minerals so there is very little contact between these two soil components. t/f
f
The forestry industry uses fertilizers most often to treat old growth stands that will produce valuable lumber. t/f
f
The great bulk of gaseous interchange between the soil pores and the atmosphere occurs by mass flow of the concerned gases.
f
The high cation adsorption capacity of vermiculite is due primarily to the substitution of silicon atoms for aluminum in the tetrahedral sheet. t/f
f
The hydrogen end of a water molecule is attracted to positively charged cations such as Na+ and Ca2+. t/f
f
The parent materials for most coastal plain soils are residual in nature. t/f
f
The percent of total pore space in a soil can be calculated if only the particle density and the organic matter content are known. t/f
f
The primary source of charge for 2:1 type clay minerals is ionization of the surface hydroxyl groups on the tetrahedral sheets. t/f
f
The property of cohesion in water stems from the attraction of water molecules for soil solids. t/f
f
The soil water potential is a measure of the potential of a soil to hold water. t/f
f
The tenacity with which water is held in soils is directly related to the soil moisture content, the higher the moisture level the greater the attraction of the water to the soil. t/f
f
The terms "ammonium fixation" and "biological nitrogen fixation" refer to the same soil process. t/f
f
The topmost horizon in most humid region forest soils is the A horizon. t/f
f
The total global soil lost through erosion is generally greater from gully erosion than from sheet erosion. t/f
f
The water potential in soils is generally considered lower than that in the atmosphere.
f
The water potential in soils is generally considered lower than that in the atmosphere. t/f
f
To enable the most consistent and appropriate interpretations, all soil samples submitted to a particular soil test lab should be taken from the same soil depth, regardless of differences in the type of tillage used or plants grown. t/f
f
Unlike Rhizobium bacteria, Bradyrhizobium bacteria are effective at fixing N, regardless of the type of plants present. t/f
f
Vapor loss from a south-facing slope in Australia would likely be higher than from a north-facing slope. t/f
f
Vermiculite and associated silicate clays have a net electropositive charge in slightly acid soils. t/f
f
While many organisms depend on the soil for nutrients and water, only a few very specialized organisms live in the soil itself. t/f
f
Soils high in organic matter commonly hold more plant-available water than comparable soils with lower organic matter levels. This is most likely due to what charteristics of the high O.M. soils?
higher field capacity
The matric potential of soil water is
not influenced appreciably by the force of gravity
Igneous rocks can best be characterized as
rocks formed when molten magma solidifies
The most common form of on-site waste water treatment for homes not hooked up to sewer lines is the
septic tank and drain field
A polypedon is a group of closely related pedons that conceptually approximates what in the United States is called a soil series. t/f
t
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. t/f
t
A soil developed in residual parent materials will likely have properties related to the properties of the rock below the C horizon. t/f
t
A soil developed in transported parent materials will likely have properties related to the properties of the rock below the C horizon. t/f
t
A soil on the south facing slope in Canada is likely to be drier and warmer than a comparable soil on a north facing slope. t/f
t
An abundance of macropores in soils helps assure an abundance of oxygen in the soil. t/f
t
An aquic soil moisture regime connotes a higher degree of soil moisture saturation than an ustic one. t/f
t
An argillic horizon is a diagnostic horizon characterized by the subsurface accumulation of silicate clays. t/f
t
Andisols are found mostly near recently active volcanoes. t/f
t
Capillary movement is made possible by the processes of cohesion and adhesion. t/f
t
Climate influences not only the rate of weathering but the type of native vegetation dominant in an area. t/f
t
Compared to conventional tillage systems, most conservation tillage systems rely more heavily on herbicides to control weeds. t/f
t
Conservation tillage has generally positive effects on soil physical properties. t/f
t
Conservation tillage is not practical in some areas of the Northern part of the United States because the practice lowers the surface soil temperature in the spring of the year. t/f
t
Drip irrigation would more likely be used in the production of apples or peaches than in the production of wheat. t/f
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Early snowfall that arrives before the cold winter weather has frozen the soil generally increases the penetration of water into the soil. t/f
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Elemental sulfur can be used to increase soil acidity and to reduce alkalinity. t/f
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Eluviation of clay, iron, and other materials is the principal process responsible for the formation of an E horizon. t/f
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Evaporation from the soil surface (E) is determined to a large degree by soil surface wetness. t/f
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Evapotranspiration includes vapor losses both from the soil surface and from the leaves of plants. t/f
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Even at pH values near 7.0 some colloids such as iron and aluminum oxides have negative surface charges less than 10 cmolc/kg.
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Flocculation is the process by which certain chemicals promote the aggregation of small, clay-size particles into larger particles. t/f
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For any soil in which it is present, the C horizon is the parent material for the B horizon. t/f
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For any soil, the bulk density is always lower than the particle density. t/f
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Fungal hyphae play an important role in stabilizing surface soil aggregates. t/f
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Histosols generally have higher organic matter contents than Mollisols. t/f
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Hydrolysis involves the splitting of water into its H+ and OH- components while hydration attaches intact water molecules to a compound. t/f
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Hydroponics is growing plants without soil. t/f
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If you want to grow azaleas in a soil that initially has a pH of 6.5 and have been told that you should apply sulfur to reduce the soil pH, you would likely need more sulfur if the soil is a clay Vertisol than if it is an clay Ultisol. t/f
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If you wanted to quickly increase the pH of a soil to 7.5 to combat a disease in cabbages you are about to plant you should use hydrated lime rather than ground limestone. t/f
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In the United States, losses of soil due to wind and water erosion decreased by nearly 40% between 1982 and 2003. t/f
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Iron and aluminum hydrous oxides are characteristic of soils that are highly weathered chemically. t/f
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Marine sediments are typical parent materials in coastal plain areas. t/f
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Mollisols are characterized by a deep epipedon that is high in organic matter. t/f
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Most irrigation systems are very inefficient with less than half the water that is taken from streams ever reaching the plants. t/f
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Most of the water flowing in rivers passed through a soil profile or over soil surfaces before reaching the river. t/f
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Most of the water in our rivers and lakes has come in contact with and has been affected by soils. t/f
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Most soil organisms are heterotrophs. t/f
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Most synthetic chemical fertilizers are inorganic salts. t/f
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Nitrogen fertilization is a significant cause of acidity in many cultivated soils. t/f
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Normal alkaline soils often exhibit deficiencies of available iron and manganese. t/f
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Organic deposits are common in areas where water ponds for extended periods of time. t/f
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Organic matter distribution in the soil is a significant criterion for differentiating epipedons. t/f
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Osmotic and matric potentials are commonly negative because the soil water has a lower energy level than that of pure water. t/f
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Oxisols are more highly weathered than are the soils of any other order. t/f
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Plants can be grown without any soil. t/f
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Practices that tend to increase the amount of organic matter in soils would be expected to reduce the global greenhouse effect. t/f
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Residual parent materials have generally been subjected to weathering for a longer period of time than have lacustrine or alluvial parent materials. t/f
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Ridge-till systems show promise in the management of somewhat poorly drained soils of the Midwest. t/f
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Russian scientists were the first to develop the concept of soils as natural bodies. t/f
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Sapric and fibric are terms used to describe peat parent materials. t/f
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Secondary minerals are recrystallized products of the chemical breakdown and/or alteration of primary minerals. t/f
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Soil air usually has a higher carbon dioxide content than the air in the atmosphere. t/f
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Soil and crop management generally has a greater influence on evaporation from the soil surface (E) than on transpiration (T) from leaf surfaces. t/f
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Soil colloids are too small to be seen with an ordinary light microscope. t/f
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Soil reaction indicates the degree of acidity or alkalinity in a soil. t/f
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Soil temperatures under an organic mulch will likely be lower than that of bare soils in the summer but higher than that of bare soils in the winter. t/f
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Soil test interpretations have been developed so that for most fields testing "high" in a nutrient, addition of that nutrient will not increase yield enough to more than pay for the cost of applying the nutrient. t/f
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Soils of good tilth and high productivity are usually characterized by stable aggregation and a high percentage of macropores. t/f
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The A horizons are more apt to be cultivated than the E horizons. t/f
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The T values are the maximum losses of soil by erosion that can be tolerated without a reduction in the soil's long term productivity. t/f
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The adsorption of water on soil surfaces encourages capillarity. t/f
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The alternate freezing and thawing of soils results in the upward heaving of plants and building foundations. t/f
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The broadest category of classification in Soil Taxonomy specifies 12 soil orders. t/f
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The cation exchange capacity of humus increases if pH increases. t/f
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The drainage class of a soil (the degree to which the soil becomes water-saturated during the year) can be judged by the presence and location of gley in the soil profile. t/f
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The family category focuses on properties affecting plant roots and suitability for engineering uses of soils. t/f
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The higher the cation exchange capacity of a soil, the greater is its buffer capacity. t/f
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The leaf area index significantly affects the solar radiation reaching the soil surface. t/f
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The leaf-like structure of silicate clays involves two kinds of horizontal sheets, one dominated by a plane of silicon atoms, the other by a plane of aluminum and/or magnesium. t/f
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The matric potential is due to the attraction of water molecules to soil solid surfaces. t/f
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The most important management factors influencing soil aeration in well-drained soils are those that determine the volume of the soil's macropores. t/f
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The name of a subgroup indicates the order, suborder, and great group of which it is a member. t/f
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The natural microbial oxidation of nitrogen released by organic matter mineralization is a major source of soil acidity. t/f
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The osmotic potential is dependent upon the presence of salts and other solutes in the soil. t/f
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The partial pressure (i.e. concentration) of CO2 in the soil pores is higher than the partial pressure of this gas in the atmosphere. t/f
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The polarity of water helps account for the attraction of water molecules for each other. t/f
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The pollution of ground water is often increased by the presence of macropores in soils. t/f
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The soil erodibility factor in the Universal soil-loss equation (USLE) relates primarily to the soil's infiltration capacity and structural stability. t/f
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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. t/f
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Vegetative barriers planted on the contour have been found to create low-cost "natural" terraces. t/f
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Vertisols are characterized by high contents of swelling-type silicate clays. t/f
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Water molecules have polarity because the electrons are not uniformly shared between the two H atoms and one O atom. t/f
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Water will move from one site in a soil with a higher water potential to an adjacent site with a lower water potential.
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While kaolinite particles are larger than those of other major silicate clays, the surface area of kaolinite per kilogram is much smaller than that of the 2:1 type minerals. t/f
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You would be more apt to find an Gelisol in Alaska than in Iowa. t/f
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You would expect the cation exchange capacities of Ultisols to be lower than those of Aridisols if the soil textures are about the same. t/f
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Mechanical weathering processes result in
the disintegration of rcoks due to differential expansion of minerals
The likelihood of pollutiing groundwater with pesticides and plant nutrients is enhanced by
the presence of macropores in the soil
The redox potential is a measure of
the tendency of a substance to accept of donate electrons
Which of the following best characterizes the field capacity of a soil
water content of a soil 24 hours after a saturating rain
If you dig a deep hole in your back yard and water started to seep into the hole it would fill the hole up to the
water table
A soil pedon is ________. a. generally larger in area than a polypedon b. a category of Soil Taxonomy c. a surface horizon used to characterize soil suborders and great groups d. a diagnostic subsurface horizon prominent in arid regions and in sandy parent materials. e. a three-dimensional unit that embodies the primary characteristics of an individual soil
e
Because of their greater surface area per unit of soil mass, silt loams soils generally have a greater capacity than loamy sand soils to ________. a. support bacterial growth b. release nutrients by mineral weathering c. adsorb gases d. adsorb water e. all of the above
e
Compared to upland soils, wetland soils would be characterized by an abundance of ________. a. SO42- b. NO3- c. Fe3+ d. CO2 e. methane
e
Granite is an example of a(n) ________. a. secondary mineral b. primary mineral c. eolian parent material d. sedimentary rock e. igneous rock
e
If the average transpiration (T) loss from leaf surfaces in a particular watershed is 10 mm/day, you expect the evaporation (E) from the soil surface to be ________. a. 5 mm/day b. 15 mm/day c. 10 mm/day d. 100 mm/day e. Impossible to calculate from the data given
e
If the soils are to be used for crop production, for which soil order would land drainage be most critical? a. Aridisols b. Inceptisols c. Mollisols d. Oxisols e. Histosols
e
If you were looking for a soil with high cation exchange capacity and were not concerned with the soil's physical properties, which of the following would most likely fit your needs? Select one: a. Mollisol b. Ultisol c. Oxisol d. Aridisol e. Vertisol
e
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. 90% water and 10% air b. 10% water and 90% air c. 25% water and 75% air d. 25% water and 25% air e. 50% water and 50% air
e
