FOR 208 Soils- Review for final

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FOR 208 Soils- Review for final
2013-06-06 18:20:02
Soils Chemistry

A review of basic chemistry ideas for those of us who have been away from it for years!
Show Answers:

  1. What is an Atomic Number?

    A number based on the number of protons in the nucleus of an atom.

    Elements are arranged on the periodic table by their atomic number.
  2. What is the smallest part of an element?
    An atom
  3. The subscript represents...?
    • The number of elemental atoms in a compound.
  4. The superscript represents...?
    • The charge of on ion.
  5. Protons have a ____________ charge.
  6. Electrons have a ________ charge.
  7. Neutrons have a ________ charge.
  8. If an atom has an equal number of protons and electrons, the atom has a ________ charge.
  9. An ion is "formed" when:
    An electron leaves or joins an atom, creating a charged atom.
  10. A cation is:
    When an atom loses an electron and becomes positively charged.
  11. A anion is:
    When an atom gains an electron and becomes negatively charged.
  12. Is an atom which has gained an electron has become:

    a) reduced
  13. An atom which has lost an electron has become:

    a) reduced
    b) oxidized
    b) oxidized
  14. OIL RIG is a way to remember the reduction or oxidation of atoms. What does it stand for?
    Oxidation Is Loss, Reduction Is Gain

    (of electrons)
  15. What is the maximum number of electrons an atom can gain or lose?
  16. Another term for oxidation number is:
  17. In the periodic table of elements, the columns (up and down) are called _________.

  18. In the periodic table of elements, the rows are called _________.

  19. How do compounds form?
    When 2 or more elements combine in fixed proportions.
  20. What do the elements on the left of the table most often do?

    Lose electrons
  21. What do the elements in the center of the table most often do?

    Both gain and lose electrons.
  22. What do the elements on the far right of the table do, and what are they called?

    They do not donate or accept electrons

    They do not form compounds with other elements

    They are inert

    • Are called Noble Gases
  23. A charge balance is:
    A neutral ("balanced") compound which has no positive or negative charge.
  24. On the Munsell Color System, in what order are the values to describe the soil color?

    • 1. Hue
    • 2. Value
    • 3. Chroma
  25. What is described by the soil Hue?
    Primary color

  26. What is described by the soil Value?
    Light to dark

  27. What is described by the soil Chroma?
    "Purity", "Deepness" or "shade" of the Hue.

  28. What happens to soil color as it ages?
    It gets darker and redder.

  29. What happens to soil color as salinity and lime content increases?
    It becomes white(ish)

  30. Sesquioxides are:
    "Dirty" soils.

    Spodic horizon, reddish-brown

  31. Humus is:
    Dark, unidentifiable organic layer

  32. REDOX is:
    The sequence that soils go through dependant on water.

    -Affects the biology and microbiology of the soil.

  33. The most abundant element in the earth's crust is:
  34. What is a mineral?
    Any repeating sequence of elements forming bonds.
  35. What is a primary mineral?
    Derived directly from molten material.

  36. What is a secondary mineral?
    Derived from primary minerals.

  37. In the most basic sense, what is a rock?
    Collections, or aggregates of minerals.
  38. What is Parent Material?
    Alluvial/Fluvial (material from which a soil is derived and transported)

  39. Parent Material

    What are Alluvial Sediments?

    Sorted in layers due to moving water's ability to carry objects.

    -Heavy stuff falls out first as the water flows.
  40. Parent Material

    What are Lacustrine sediments?

    Very fine sediments deposited into a lake or pond as water slows.

    -Very fine particles, such as clay or silt.
  41. Parent Materials

    What are Aeolian/Eolian deposits?

    Wind blown material.

    -Sand dunes
  42. Parent Materials

    What is Colluvium/Glacial Till?

    Gravity pulls material downhill.

    -Is mixed up material (no wind or water to sort materials)

    -Rounded cobbles are indicative of glacial till.
  43. Parent Materials

    What are Marine Sediments?

    Coastal, usually very fine sediments.

    -Usually silts or clays, but can be sandy if coming from a fast moving river.
  44. Parent Materials

    What is Residual Material (Residuum)?

    Material that develops on top of bedrock, weathering in place.
  45. Soil Orders

    What are Spodosols?
    Soils in which amorphous mixtures of organic matter and aluminum, with or without iron, have accumulated.

  46. Soil Horizons

    Alluvial is:
    PM transport/Streams

  47. Soil Horizons

    Elluvial is:
    Zone of accumulation

    -B horizons

    -"Emigration" (moving from one location to another)-translocations

  48. Soil Horizons

    Illuvial Is:
    Zone of Loss

    -E horizons

    -"Immigration" (areas of concentration) of mobile soil components.

  49. What are the differences between Ferrous and Ferric?
    Ferrous= Fe 2+.....GREEN

    Ferric= Fe 3+........RED...Oxidized

  50. Soil Structure

    How is Blocky soil described?
    -associated with compaction

    -lacustrine, alluvial, sedimentary

  51. Soil Structure

    How is Columnar/Prismatic soil described?
    -associated with compaction

    -lacustrine, alluvial, sedimentary

  52. Soil Structure

    How is Platy soil described?
    -associated with compaction

    -lacustrine, alluvial, sedimentary

  53. Soil Structure

    How is Structureless soil described?
    -single grained

  54. The "symbol" for Bulk Density is:
  55. Write out the Db equation.
    D=m/v  g/cm3
  56. Of the following forms of iron, which one is reduced?

    A. Fe+
    B. Fe+3
    C. Fe+4
    D. Fe+2
    D. Fe+2
    (this multiple choice question has been scrambled)
  57. Why does HCI (Hydrochloric acid) react with certain minerals?
    What is this reaction or process called?
    It is an acid based reaction.

    Acid+Base= Reaction

  58. What is Bioturbation?
    "Mixing of life" in soil

  59. Soil Densities

    List the common soil densities from smallest to largest, starting with Peat.
    • Peat =0.1 to 0.7 g/cm3
    • Volcanic soils =0.5 to 0.9 g/cm3
    • Forest topsoil =0.8 to 1.2 g/cm3
    • Ag field =1.0 to 1.7 g/cm3
    • Hardpan =1.6 to 2.1 g/cm3
  60. What is the biggest element in regards to Organic Matter?
  61. What terms describe the three basic kinds of organic soil materials?

    -list in order from most identifiable


  62. Where, on earth, is the greatest amount of carbon stored?
  63. Decomposition and Primary Production

    (diagram, no question)
    • CH2O+O2=CO2+H2O+energy
    • -----------Respiration----------->
    • <-------Photosynthesis----------
  64. Organic Chemistry is based on what element?

    -always present, but nitrogen can be lacking.
  65. If high level of ________ is present, breakdown of organics will be __________.
    If high level of carbon is present, breakdown of organics will be slower.
  66. What are some benefits of Organic Matter?
    Will increase biological activity

    Nutrient retention

    Dark colors (BIG identifying factor)

    • Will decrease Db (amount of air/voids)
    • Db-H2O Infiltration
    • (decreased bulk density will increase water infiltration=GOOD)

    Helps with PH buffering (resilience of soil to resist change in PH)

    Uptake toxins (removes toxins)

  67. The 5 master Soil Horizons, in order from the surface--> down are:
    • O=Organics
    • A=Mineral Horizon
    • E=Zone of Loss
    • B=Zone of Accumulation
    • C=Parent Material Layer
    • (sometimes R)=Bedrock

  68. What 5 things does the Physical and Chemical Soil Process depend on?
    • Parent Material
    • Additions: inputs, eolian deposits (dust), water, growing organics
    • Losses: outputs, calcium carbonate, organics, clays
    • Transformations: breaking down particle sizes
    • Translocations: movement inside profile
  69. Describe the "O" Horizon.
    • Will always be at the surface
    • In forests- will have "O" horizon with litter on top
    • Won't find in grasslands
    • Will find in forests or peat bogs
    • Has dominant organic derivitives
    • Fibric, Hemic, Sapric
  70. Describe the "A" horizon.
    • Mineral horizon
    • Bigger materials(finer materials have been transported down)
    • Over 85% sand, silt, clay
    • Less than 15% organic material
    • Darker colors due to influence of "O" horizon
  71. Describe the "E" Horizon.
    • Zone of Loss
    • Shows up as depleted matrix, or void of color
    • Mobile materials washed down
    • Elluvial
    • Not always directly on top of "B", but there is always a "B" horizon somewhere below it.
  72. Describe the "B" Horizon.
    • Zone of accumulation
    • Harder, blocky structure
    • Where clay has accumulated
    • Where all the "good stuff" is at
  73. Describe the "C" Horizon.
    • Parent Material Layer
    • Undeveloped "stuff" that was deposited
    • On it's way to becoming soils
  74. Describe the "R" Horizon.
    • Bedrock
    • Impedes or affects water flow
    • Can't dig through it
  75. What are soil colloids?
    Tiny material, typically organic

  76. Another term for 0.00?mm is:
    A micron
  77. What is Cation Exchange Capacity?
    CEC= the sum of total exchangeable cations that a soil can absorb.

    CEC= Cmolc/Kg soil
  78. What is Avogadro's number?
  79. Low Ph means an abundance of:
    Aluminum and Hydrogen
  80. The higher the CEC, the more ______ a soil is.
  81. Low hydrogen concentration=  ?
    High acidity
  82. What does pH describe?
    The amount of hydrogen ions available
  83. What is Base Saturation?
    The % of cation exchange sites taken up by bases.

    %BS= Exchangable base-forming cations(Cmol+/Kg) / CEC (Cmol+/Kg)
  84. What is Adhesion?
    H2O sticking to other things
  85. What is Cohesion?
    H2O sticking to itself
  86. What is Capillarity?
    The movement of water through a hydrologically conductive area.

  87. What is Osmosis?
    Going from low to high concentrations

    -water uptake purely through low salinity to high salinity
  88. Explain the differences between:
    -Field Capacity
    -Wilting Point
    Saturation= soils contain too much water

    Field Capacity= soils are holding as much water as they can

    Wilting Point= not enough water available
  89. What 5 things does soil water content depend on?
    • -texture class
    • -% of pore space
    • -pore size
    • -clay type
    • -Bulk density
  90. Describe Saturated Flow.
    Water moving while all soil pores are filled-water moves from high energy (top) to low energy (bottom)


  91. Describe Unsaturated Flow.
    Water moves up from a water table into the soil by capillarity- is wicked up into root zone, but can also be wicked down.

  92. What is another water movement type within soils, besides Saturated and Unsaturated?
    Water Vapor

    -significant movement for drier soils-water moves from high potential to low potential

  93. What is Infiltration, and Infiltration Rate?
    Infiltration= movement of water into soil

    Infiltration Rate= the rate at which water moves into soil
  94. What is Percolation, and Percolation Rate?
    Percolation= water movement through a soil

    Percolation Rate= the rate at which water moves through a soil
  95. What is the Fate of Soil Water? (4)
    1. Uptake by plants

    2. Storage

    3. Deep percolation-ground water recharge

    • 4. Redistribution on landscape
    •     -runoff
    •     -lateral flow
  96. What increases pH in soils?
    Aluminum and Hydrogen

    -these influence pH and make soil more acidic (lowers pH)
  97. 2.65g/cm3 specifically refers to what mineral?
  98. What is Oregon's state soil? What Soil order, color, FEF is it, and what is it good for?
    State soil= Jory

    Order= Alfisol

    Color= Red

    FEF= Clay

    Good for: Growing D-fir, wine grapes, and dying t-shirts!

  99. What are Macro nutrients?
    Nutrients in the soil which are always needed.
  100. What are Micro nutrients?
    Nutrients in the soil which may not always be needed, or in smaller amounts.
  101. What are some examples of Macro nutrients?
    N,P,K, carbon, hydrogen, oxygen, sulfur, calcium, magnesium
  102. What are some examples of Micro nutrients?
    Iron, Mn, B, Zn, Cu, Cl, Co, Mo, Ni
  103. What does Phosphorous availability depend on?
    Soil Orders
  104. How do plants cope with limited Phosphorous?
    They develop symbiotic relationships

    They grow more/longer roots
  105. What are some conservation methods to preserve soil nutrients/soil integrity?
    (think dust bowl)

    Cover crops/grasses

    Conservation tillage

    Recycling (manures, biosolids)

  106. What are nitrogen nutrients?

    Hint: what do we want for plant uptake?
    • Nitrate
    • Ammonium
  107. What is Hypoxia?

    Lack of oxygen, low oxygen conditions
  108. What is Eutrophication?
    Increased nitrates (such as fertilizer in agricultural lands) in soil are undesirable to plants.

    Low nutrient content

  109. Nitrogen Cycle review

  110. Inorganic/ Organic nitrogen.

    Which of these forms of nitrogen can plants use?
    INORGANIC nitrogen- inorganic nitrogen is broken down to a more usable form.

  111. Nitrogen Processes

    What are some fates of nitrogen in soils?
    • Nitrate leaching
    • Dentrification
    • Fixation
    • Mineralization
  112. What is Dentrification?
    The process of releasing nitrogen back into the atmosphere.

    Soils become (anaerobic?)

  113. Can soils have too much Phosphorous?
    NO! There isn't much anyway, and plants lock it up.
  114. Do we have phosphorous dependent plants in our area? (Central Oregon)
    NO! The phosphorous in our soils is locked up.
  115. Potassium deficiencies can lead to ________ and reduce __________.
    Potassium deficiencies can lead to chlorosis and reduce photosynthesis.
  116. Deficiencies of sulfur can lead to __________.
    Deficiencies of sulfur can lead to chlorosis.
  117. What does higher aluminum content mean?
    Lower pH.
  118. What are BMP's?
    "Best Management Practices"

    -Buffer strips, trap sediments, and take up nutrients.

  119. What are the 3 size classes for soil biota? (Flora and Fauna)
    • Micro <0.1mm
    • Meso 2mm - 0.1mm
    • Macro >2mm
  120. Which 2 nutrients is our area deficient in?
    Potassium and Nitrogen
  121. What does fauna prey on?
    Flora and other fauna
  122. Give examples of Macro, Meso and Micro FAUNA.
    Macro: gopher, earthworms, mice, ants, slugs, beetles

    Meso: mites, springtails, sowbugs

    Micro: nematodes, rotifers, amoebae
  123. Give examples of Macro and Micro FLORA.
    Macro: feeder roots, mosses

    Micro: root hairs, algae, fungi, bacteria, cyanobacteria, actinomycetes
  124. What effect does Macro Fauna have in soils?
    Increase soil porosity

    Mix soil layers (bioturbation)

    Reduce OM to micro size
  125. Energy Chain

    What are Primary Producers?
    Vascular plants, algae, lichens----> photosynthesis

  126. Energy Chain

    What are Primary Consumers?
    Herbivores, detritivores -------> use energy stores in plant residues

  127. What are Secondary Consumers?
    They eat the dead bodies of primary consumers


  128. What is an autotroph?
    • Something that gets its food from:
    • The sun
    • CO2
    • Carbonates
  129. What is a heterotroph?
    Something that gets its food from:

    Other organisms

    *Many heterotrophic organisms are the recyclers (decomposers)
  130. Name some factors that influence decomposition rates.
    • Aerobic or anaerobic
    • Moisture
    • Temperature
    • Food source
    • None of the above? ---> dormancy
  131. Mycorrhizal relations are:
    An integral part of a functioning ecosystem

    Often vital to success of crops

    Symbiosis of plant roots and fungi
  132. What is the Q10 principal?
    For every 10°C increase in temperature, you will get 2-3x biotic productivity.
  133. Bacteria

    What is Enzyme Action?
    Soil bacteria are being used to remediate contaminates (Exxon Valdez, MTBE)
  134. Bacteria

    What are transformations?
    Oxidation or reduction of elements (nitrification, wetland soils)
  135. Bacteria

    What is cyanobacteria?
    Photosynthetic nitrogen fixers
  136. Bacteria

    What are actinomycetes?
    • Provide similar functions as fungi and bacteria
    • Numerous in soils
    • N-fixation for Alnus
    • Decompose leftovers
    • Give soil that "fresh dirt" smell
  137. What is anthropogenic erosion?
    Human caused/ accelerated  BAD!

    • Water: affects 11 million square km annually
    • Wind: affects 5.5 million square km annually
  138. What is natural erosion?
    Geologic/ natural   OK
  139. What is Desertification?
    • Water becomes scarce
    • Exposed to direct sunrays
    • Loss of water storage in soil

    • Examples:
    • Change from PIPO forest to sagebrush steppe
    • Dust Bowl
  140. What happens to soils when erosion goes bad?
    • Loss of fertility (depth, nutrients, tilth)
    • Pollution (eutrophication, pesticides)
    • Loss of organic soil
    • Degradation (compaction, loss of structure, chemical contamination)
    • Desertification
  141. Name and describe the 3 types of erosion by water.
    Sheet erosion-water moving across surface in thin sheets

    Rill erosion-more concentrated flow/more volume per unit area

    Gully erosion-higher velocity due to greater volume

  142. "Predicting Erosion by Water"

    What does USLE stand for? What are its components?
    Universal Soil Loss Equation

    • I=soil erodability
    • C=climate factor
    • K=roughness
    • L=Length
    • V=cover
  143. Erosion by Wind

    Name and describe the 3 types of wind erosion.
    Saltation: airborne soil particle flies through the air, dislodging more soil. "sandblaster"

    Creep: movement of soil on a shorter length scale. "sandunes"

    Suspension: occurs when very fine dirt and dust particles are lifted into the wind. Can be carried long distances.

  144. What is Mass Wasting?
    Think Landslides...

  145. More rain= more leaching which = ?
    LOWER pH
  146. What is an Epipedon?
    • The uppermost horizon used to classify a soil within a designated area.

  147. Name some varieties of Epipedons.
    • Mollic and Umbric- certain color and pH
    • Ochric- "garbage can variety", leftover category can take anything
    • Histic- a layer (one or more horizons) that is characterized by saturation (for 30 days or more, cumulative) and reduction for some time during normal years (or is artificially drained) and either:
  148. Can a Histosol have a histic epipedon?
  149. Subsurface Diagnostic Horizons

    Name and describe some subsurface diagnostic horizons.
    Albic- what is left over from an "E" horizon

    Argillic- clay rich

    Kandic- clay rich

    Natric- clay rich

    Spodic- Just below the "E" horizon (spodosols)

    Calcic- calcium

    Petrocalcic- impenetrable calcium

    Gypsic- gypsum
  150. From wettest to driest, name the 5 soil moisture regimes.
    • Aquic
    • Udic
    • Ustic
    • Xeric
    • Aridic
  151. What are some techniques for soil mapping?
    Soil descriptions

    Delineate soil boundaries

    Ground penetrating radar

    Electromagnetic induction
  152. What are some human causes of dryland soil degradation?



    Arable farming

  153. Define "Soil Quality"
    The capacity of a soil, within a natural or managed landscape, to sustain animal and plant productivity, maintain or enhance water and air quality, and support human health and habitation.
  154. What are some issues related to soil quality?
    • Erosion losses
    • Sedementation
    • Compaction
    • Infiltration
    • Crusting
    • Nutrient loss/imbalance
    • Pesticide carryover
    • Salinity
    • pH chemistry
    • OM
    • Biological activity
    • Weeds/pathogens
    • Wetness
    • Global warming
  155. Name the soils that are susceptible to compaction, in order from least to most.
    • Peat
    • Volcanic
    • Forest soils
    • Agricultural fields
    • Hard pan
  156. What is hypoxia?
    WITHOUT oxygen
  157. What are some ways Nutrient and Chemical control is regulated?
    • Precision agriculture
    • Proper nutrient management
    • BMP's
    • Slow release fertilizers
    • Encourage natural fertility
    • Integrated pest management
    • Crop rotation and staging
  158. How is Salinity controlled?
    • Re-establishing deeply-rooted vegetation
    • Encouraging water efficiency
    • Not recycling water
    • Avoiding marginal areas
  159. Describe "Saltation", "Creep", and "Suspension" when talking about wind erosion.
    Saltation: "sandblaster"

    Creep: "sand dunes"

    Suspension: "remains in air"
  160. Unpolluted rainwater is naturally slightly acidic due to:
    Atmosperic CO2 (carbon dioxide)
  161. What is base saturation?
    The percent of cation exchange sites taken up by bases.
  162. What is a sesquioxide?
    The concentrations of aluminum and iron oxides.

  163. How does water weather soils and geology?
    Physically and Chemically
  164. What is the sub-order for a histic gelisol?
  165. Water erosion models look at what major factors to assess erosive potential of landscapes?
    • Soil quality
    • Slope characteristics
    • Vegetative cover
    • Erosion control practices
  166. What does H+ mean?
    Hydrogen ion concentration

    (this is a part of the pH equation)
  167. How do roots get their water? What process is used and what are the relative salt concentrations in and outside the root cells?
    • Osmosis,
    • higher salt in root cells, lower salt in soil water.
    • Water permeates cells and goes from low to high salt concentrations.
  168. What is a fancy term for a dirt clod?
    A Ped
  169. What are the relative suspension/transport times for each of the particles in the fine earth fraction?
    • Sand-fast
    • Silt-medium
    • Clay-slow
  170. What is a colloid?
    Smaller than 2 micron particles. (clay or humus)
  171. An aquid is a suborder for what type of soil? (descriptor and order)
    Aquic Aridisol
  172. What is a Surface Diagnostic Horizon?
  173. Explain capillarity.
    Hydro-logically conductive material transporting water through adhesion and cohesion.
  174. What is a mole?
    6.02x 10E23 molecules of something
  175. What is the major difference between natural and anthropogenic erosion?
    The speed of erosion
  176. Which texture size is most susceptible to erosion?
  177. What is the term for water vapor leaving soil or vegetation?
  178. Draw a water molecule and indicate concentrations of charge.
    It should look something like this: