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73 Cards in this Set
- Front
- Back
Which of the following is not a function of soil pores? |
Provider of shear strength |
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Soils forming from recently deposited, unaltered basalt would be considered to have residual parent material. |
True |
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Match the six master horizons with their descriptions: O |
Composed primarily of organic matter. |
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Match the six master horizons with their descriptions: A |
The top mineral horizon, enriched with organic matter from plants at the soil surface. |
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Match the six master horizons with their descriptions: E |
Highly leached, lighter in color than other horizons. |
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Match the six master horizons with their descriptions: B |
Illuviated horizons; typically accumulating clays, iron, and aluminium oxides. |
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Match the six master horizons with their descriptions: C |
The least developed horizon, often similar in appearance to the parent material. |
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Match the six master horizons with their descriptions: R |
Consolidated rock, minimal weathering. |
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A soil profile always has all six of themaster horizons. |
FALSE |
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What is the main difference between physicaland biogeochemical weathering? |
Biogeochemical weathering converts primary minerals into secondary minerals. |
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Which of the following is not a soil-forming (pedogenic) process? |
Exchanges |
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The three soil profiles drawn below make up a chronosequence. Select the answer which orders the three profiles from youngest to oldest (i.e. 1, 2, 3 or 3, 2, 1, etc.). |
Middle, right, left. |
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The three soil profiles drawn below make up a toposequence. Select the answer that correctly labels their topographic position - which profile is the summit, which is the backslope, and which is the toeslope? |
Left = Summit Middle = Toeslope Right = Backslope |
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In which horizon would you expect to find granular structure? |
A |
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If you came across an E horizon, is its color more likely to be 10YR 2/2 or 10 YR 7/1? |
10YR 7/1 |
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Match the soil order with its description: Histosols |
Soil made largely of organic matter |
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Match the soil order with its description: Aridisols |
Generally lighter colored soils found in dry environment, sometimes with accumulations of calcium, gypsum, soluble salts, or sodium. |
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Match the soil order with its description: Mollisols |
Calcium-enriched soils formed under prairie grass. |
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Match the soil order with its description: Entisols |
Poorly developed soils that lack a B horizon. |
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Match the soil order with its description: Inceptisols |
Poorly developed soils that have a B horizon, though it cant be enriched with clay. |
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Match the soil order with its description: Gelisols |
Solids with a permafrost layer. |
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Match the soil order with its description: Vertisols |
Soils with high shrink-swell clay content. |
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Match the soil order with its description: Alfisols |
Most commonly found under deciduous forests. |
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Match the soil order with its description: Ultisols |
Weathered yellow or red soils with a B horizon that has less than 35% base cations. |
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Match the soil order with its description: Oxisols |
Extremely weathered soils found in the tropics; intensively leached and very deep |
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Match the soil order with its description: Spodosols |
Soils formed under coniferous forests with intensive acid leaching, forming Bh and Bs horizons. |
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Match the soil order with its description: Andisols |
Soiled formed in volcanic ash or cinders. |
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To which soil order does a soil in the great group Durixeralfs belong? |
Alfisols |
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A soil in a bog or wetland, would likely have which soil moisture regime? |
Aquic |
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Using the texture triangle, what texture does a soil with 66% sand, 18% clay, and 16% silt have? |
Sandy Loam |
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After 44 seconds, all of the clay in the hydrometer has dropped out of suspension. |
False |
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A lithologic discontinuity has a particular notation in a horizon description. Which of the following profiles have a lithologic discontinuity? Select ALL the answers that are correct. |
Ap-BA-2Bt1-2Bt2-2Btk-3Bkqm-3Bk & A1-A2-BA-Bt1-Bt2-2Bt3-2Bt4-2R |
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When there is a horizon between two distinct horizons (say you've identified an A, transition, and a B), the proper notation for this transitional horizon is AB assuming that the A part is more dominant. |
True |
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From the following locations, select the one in which you would be most likely to find an Ajj horizon |
Fairbanks, AK |
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A surface horizon produce by long term spading and manure addition is called a _________ epipedon. |
Plaggen |
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A soil with aquic conditions can have an aridic soil moisture regime |
TRUE |
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Most mineral soils have a particle density between 2.60 g/cm3 and 2.75 g/cm3. |
TRUE |
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Deeper in the soil profile, bulk densities are generally lower. |
FALSE |
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A soil with a bulk density of 0.46 g/cm3 would likely belong to which soil order? |
Histosols |
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Compaction is a problem because it ________________ |
Reduces the infiltration of water into soil, Limits the rooting depth of plants, Increases runoff |
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Fine textured soils tend to have fewer micropores than coarse textured soils: |
FALSE |
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Clayey soils tend to compact more because of their ______________ |
high cohesion and plasticity |
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What is glomalin? |
A cementing agent produced by mycorrhizal fungi. |
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Conventional tillage (e.g. moldboard plowing) is damaging to soil structure and can increase bulk density over time. |
TRUE |
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At room temperature, water has a density of approximately 1 g/cm3
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TRUE |
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Using the simplified capillary equation, h = 0.15/r, what is the height of capillary rise in a tube with a diameter of .1 cm? |
h = 0.15/r = 0.15/0.05cm = 3cm |
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Soils with finer textures (e.g. clays) will have greater capillary rise than coarse soils (e.g. sands) due to their smaller pores. |
TRUE |
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You perform the infiltration rate experiment on two different soils: a loamy sand, and a silty clay. Which soil is likely to have the higher infiltration rate? |
Loamy sand |
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Imagine for a moment that you are a farmer. You use conventional tillage in your farming operation and drive a tractor with narrow tires. Over time, you start to observe that plants no longer grow in your tractor's tire tracks and furthermore that water tends to pool in these tracks when it rains. Has the soil bulk density in the tire tracks increased or decreased? |
Bulk density increased |
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The matric potential of a soil at field capacity is generally: |
-10 to -30 kPa |
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The difference between PET and actual ET is called the ___________ |
water deficit |
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The zone of wetting by capillary movement is known as the ____________. |
capillary fringe |
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If an irrigated field (with accompanying cultivated crop) has a Field water efficiency of 38%, this means that _____________________ |
62% of the applied irrigation water is not transpired by the crop |
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Once a soil is depleted of oxygen, the soil environment is said to be _____________ |
Anaerobic |
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Hydric soils generally have a _________ or ___________ moisture regime. |
aquic, peraquic |
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Why is it problematic if permafrost soils, such as Histels, begin to thaw? |
Organic matter frozen in these soils (and thus prevented from decomposing) will suddenly begin to break down, releasing huge amounts of carbon dioxide. |
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In the capillary rise experiment, the side of the capillary wedge with the folded aluminum foil in it had greater capillary rise than the other side. |
FALSE |
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In the week 7 lab, the yellow dye in the Kool-Aid behaves like a ___________, while the blue dye behaves like a ___________. |
anion, cation |
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The colloidal fraction of soil includes ________ and _______ particles. |
clay, humus |
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Which of the following is not a common soil cation? Na+, H+, Ca2+, Mg2+, Cr3+ |
Cr3+ |
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If a cation is adsorbed to a soil colloid, it is _________ |
loosely held on the surface of the colloid |
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Which colloid has the greatest net negative charge? |
Humus |
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Iron & aluminum oxide-based clays are commonly found in tropical soils, like Oxisols. These clays have significant anion exchange capacity (meaning that the colloids have a net positive charge). Why does this property make these soils difficult for agricultural use? |
Plant nutrients are largely cations, which are repelled by the positive charge of the colloids, washing them out of the soil before plants can take them up. |
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The accumulation of organic matter tends to acidify soils. Thus, Histosols tend to have a very basic pH. |
FALSE |
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The application of ammonium-based fertilizers tends to decrease soil pH. |
TRUE
|
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Plants suffering from aluminum toxicity often show symptoms of phosphorous deficiency. |
TRUE |
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Which of the following statements is true about saline seeps in semiarid regions? |
Saline seeps are often created or worsened by planting annual crops that use far less water than did the natural vegetation. |
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Electrical conductivity (EC) of a soil-water paste is measured to estimate the ___________ of the soil. |
Salinity |
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What treatments(s) would be effective in reclaiming 100 acres of saline-sodic soil? |
both answers 2 and 3; irrigate with diluted sulfuric acid solution, mix finely ground gypsum into the soil and then irrigate with an excess of water. |
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Compared to the original topsoil from which the sediment was eroded, sediment typically contains ______________. |
two to three times more phosphorus and potassium |
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Which of the following statements is accurate? |
Erosion is most likely when rainfall rate exceeds the soil's infiltration capacity |
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What is "riprap," used on many construction sites? |
all of the above; a kind of "hard armor", a layer of large rocks, a practice used to stop gully formation by scouring |
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Which of the following statements is accurate regarding conservation tillage? |
One of the benefits of conservation tillage is that the water-holding capacity of the soil is generally increased. |