Soils 205-General Soils

Study questions- Quiz 4

 

  1. What are the five soil forming factors?
  2. How does rock type influence soil texture and fertility?
  3. List and describe the types of parent materials that are transported by water, ice, and wind.
  4. Draw graphs showing the influence of temperature or precipitation on clay formation, depth to carbonates, and % organic matter.
  5. Why are A horizons more common in grassland soils than forest soils?

  6. A

     

     

    Bg1

     

    Bg2
     

    A

     

    Bt

     

     

    BC
     

    A

     

    BC

     

    C
     
    Match the soil profiles below to the following landscape positions.  Explain your answer. 

     A.  Summit            B.  toeslope           C.  backslope

 

 

 

 

 

 

 

 

 

 

 

 

 

  1. What are the four soil forming processes? 
  2. If all four processes are active in all soils, why aren’t all soils alike?
  3. Draw a representative profile for each of the soil orders.
  4.   What is the major factor limiting land use possibilities for each of the following soils? 
    1. Aridisols
    2. Vertisols
    3. Ultisols
    4. Gelisols
    5. Andisols
    6. Oxisols
    7. Spodosol
    8. Histosols

 

  1. What is humus?
  2. How is the soil organic matter related to global warming? 
  3. What are the colloidal characteristics of humus?  How does humus influence soil?
  4. Give an example of an important member of the macrofauna, mesofauna, and microfauna; explain how humans benefit from the activities of each of these groups.
  5. Describe an activity carried out by fungi, bacteria, and actinomycetes (one for each group) that benefits human beings.
  6. After adding sawdust mulch to his field, a farmer’s plants turn yellow and die.  Why, in terms of N availability, did this happen? 
  7. How does soil drainage affect organic matter accumulation?
  8. Explain the following pathways in the nitrogen cycle.  What are the beginning and end products, and the conditions favoring each?

Mineralization

Immobilization

Nitrification

Ammonia volatilization

NH4+ fixation

Denitrificaiton

Leaching

           

     20.  List two ways in which humans have impacted the N cycle.

    21.  What are two impacts of the activities in question 20?

    22.  How are deficiency symptoms of S different from those due to a deficiency of N?

    23.  Compare the sources and sinks of soil N, P, and S.

    24.  What forms of N, P, and S are considered plant available?

    25.  If the three most common forms of P in soil solution are plant available, why are P        

          deficiencies so common? (what are the three main problems with P nutrition?)

    26.  Why are N, P, and S so important to plant nutrition?