1.
Chapter 2 –Review Questions
Name the five soil-formation factors and give an example of the effect of each on soil formation.
2.
Draw a soil profile containing seven distinct horizons in the correct order, and label them. Indicate topsoil,
subsoil, and solum.Hint: You will use more than just the regular master horizons, and there are many possible
configurations.
3.
Describe the major parent materials and vegetation as well as climate that contributed to the soils of your
locality. Describe how they influenced your soils.
4.
5.
What do alluvial fans, floodplains, deltas, and terraces have in common? How are they different?
Would you be likely to read a soil description that includes an At horizon? Use Appendix 3. Explain your
answer.
6.
Discuss the four soil-forming processes and give examples of each.
7.
You have two very different soils that are only 100 yards apart. Which one of the five soil-forming factors
(parent materials, climate, topography, life, and time) most likely explains the differences?
8.
Running water removes soil from the surface by erosion. Which of the four soil-forming processes does this
exemplify, and how might the soil-forming factors affect it?
9.
Organic matter tends to increase from west to east in the United States because of increasing rainfall. Yet,
some of the highest organic matter soils are in the plains states, which are relatively dry. Explain why.
10. Compare the nutrient contents of soils derived from the granite-, sandstone-, and limestone-based materials
shown in Figure 2-5. What nutrients are each high or low in?
11. Clay minerals are important soil particles that form in the soil during weathering, a subject of a later chapter.
Elements such as potassium and magnesium are needed for clay to form in the soil. Would a residual soil
formed from Hinckley sandstone (seeFigure 2-5) contain much clay?
12. If the climate in a certain location changes to be warmer and drier, would you expect soil development to
change over time? Suggest a couple of ways it might change.
13. Using Appendix 3, answer the following questions:
1.
Sometimes an older soil gets buried and a new soil forms on top. What would a buried A horizon be labeled
as?
2.
The peat moss harvested from peat bogs for horticultural use in potting soils is moderately decomposed
organic matter. In what soil layer would this peat be harvested?
3.
Caliche, mentioned in the text and often a headache for landscapers in the American Southwest, is a B horizon
cemented by carbonates. What would be the complete designation of a caliche horizon (there will be two
subscript letters)?
14. Describe several physical, chemical, and biological roles that water plays in soil formation, giving examples.
15. The base of a slope like that of Figure 2-15 is called the toeslope. How would toeslope soils differ from those at
the shoulder of the same hill? Explain why.