Soils 205-90

Homework 4


1)  List the four soil forming processes and give a brief example of how each one may influence the developing soil profile. (4)







2)  If all four soil forming processes are active in all soils, why are soils not all alike? (2)





3)  What is the transport or depositional processes for each of the following kinds of parent materials? (3)

  1. Lacustrine


  1. marine


  1. Till and moraine


  1. Alluvial


  1. Colluvial


f.  Eolian



4)  Describe three types of alluvial deposits. (3)







5)  Under what type of environmental conditions are you most likely to find the accumulation of organic parent materials? (1)




6)  How does mechanical weathering differ from chemical weathering? (1)




7)  Match soil A, B, and C with the landscape position on which they most likely formed on and explain your answer (3)

                           Soil A                           Soil B                              Soil C

Text Box: A
Text Box: A
Text Box: A












Text Box: 2.________
Text Box: 3._________













8)  What is the difference between an A and an E horizon?(1)



9)  What is an AB or BE horizon?(1)



10)  Place the following groups of horizons in the order that they would occur in the profile from the surface of the soil downward (2)


a.  C, Bsh1, A, E, Bsh2, BC


b.  Bt2, Ap, R, AB, Bt1, C




11)  Which master horizon is characterized by having had illuviation taken place?(1)



12)  How is a Bt horizon different from a Bk horizon?(1)



13)  Explain how the following diagnostic horizons differ from each other.(3)

a.  mollic vs. umbric



b.  ochric vs. umbric



c.  melanic vs mollic



d.  spodic vs argillic



e.  duripans vs fragipans



f.  albic vs. calcic




14)  Which of the soil forming factors is most reflected in the properties of the soil horizons of Entisols?(1)






15)  Give a limitation for landuse for each of the following soil orders (4)

            a.  Vertisols _______________________

            b.  Gelisols________________________

            c.  Histosols_______________________

            e.  Ultisols________________________



16)  What property distinguishes an Ultisol from an Alfisol, which one is better suited to agricultural production and why?  Which one is more highly weathered?(3)









17)  Using the diagrams provided, draw in the typical horizons found in the following soil orders (5)


Text Box: 100 cm










18)  Explain how the following soil orders differ from each other.(3)

a.  Vertisols vs Entisols



b.  Alfisols vs Mollisols



c.  Andisols vs Inceptisols



d.  Oxisols vs Ultisols



e.  Spodosols vs. Oxisols



f.  Histosols vs. Entisols




19)  What is the soil order for each of the following soils?(2)

a.  Mollic Cryoboralf

b.  Xerollic Natrargid

c.  Terric Medisaprist

d.  Entic Cryandept



20)  Supply the following information for the Athena soils which is classified as a fine-silty, mixed, mesic Pachic Haploxeroll (3)

a.  order =

b.  family =

c.  subgroup formative element=

d.  series =

e.  great group =

f.  suborder formative element =



21)  Why do some soil maps use associations as mapping units rather than soil series or phase?(1)



22)  How is a Soil Survey different from just being a soil map?(1)




23)  Describe one way in which you may use a soil survey in your current or future career.(1)