Download Name: Per.: Ch. 5.2: Soil Notes What is regolith? What is soil and

Name:
Per.:
Ch. 5.2: Soil Notes
1.
What is regolith?
2. What is soil and what are the three important characteristics of soil?
3. What are the 4 components of soil?
4. What is humus and how does it benefit soil (list 2 benefits)?
5. In good quality soil (Figure 10), what percentage of the soil is:
a.
Mineral matter __________%
b.
Organic matter __________%
c.
Water
__________%
d.
Air
_________%
6.
Why do plants have a difficult time growing in sandy soils?
7.
Why do plants have a difficult time growing in clay-rich soils?
8.
What soil type is best for plant growth? Why? (2 reasons)
Soil Textures: Use the diagram below to answer questions 9 – 12.
9.
What type of soil has 70% sand, 10% clay, and 20% silt? __________________________
10. What type of soil has 50% clay, 30% silt, and 20% sand? ___________________________
11. What type of soil has 40% clay, 10% silt, 60% sand? ______________________________
12. What type of soil has 90% silt and 10% sand? ___________________________________
Soil Structure
13. What can soil structure affect? (3 things)
Soil Formation
14. What are the most important factors in soil formation?
Parent Soil
15. What is the difference between residual soil and unconsolidated deposits?
16. Describe 2 ways that parent material influences soils?
Time
17. How does time affect soil?
Climate
18. Climate has the (least/greatest) effect on soil formation.
19. Temperature and precipitation can influence the ___________, _____________, and
___________ of weathering that produces soil.
20. Hot, wet climates produce (mechanically/chemically) weathered soils.
21. Cold, dry climates produce (mechanically/chemically) weathered soils.
Organisms
22. What is the main source of organic matter in soil?
23. How do microorganisms like fungi and bacteria influence soil?
24. How do burrowing animals like earthworms help soil?
25. How do nitrogen fixing bacteria help soil? What do they add to it?
26. What do organisms require nitrogen for?
27. Give 3 examples of plants that have nitrogen fixing bacteria on their roots.
28. What form of nitrogen do nitrifying bacteria turn ammonia into? (This is the form absorbed by
plants)
29. What is the name of bacteria that take nitrates and turn them into nitrogen gas in the air?
Slope
30. How do steep slopes affect soil? Why is it difficult for plants to grow on steep slopes?
Soils Worksheet – Part II
31. Soil varies in ________ _____________, ___________________, __________________, and
___________________ at different depths.
32. These vertical variations or divisions of soils at different depths are known as ____________.
The Soil Profile
A Horizon
33. aka: _________________________
34. Mostly made of (describe things you would find here.
What is in abundance?):
B Horizon
35. aka: ____________________________
36. Contains:
37. How can you identify the where the B horizon ends?
(what could you look for?)
C Horizon
38. Describe the C horizon:
39. What is below the C horizon?
Soil Types
40. What is the most important factor in soil formation? _____________________
41. List 3 types of soil: ____________________________________________________
Pedalfer
42. What climate are pedalfers found? ________________________________________
43. What geographic region of the U.S. are they found? __________________
43. What type of ecosystem are they found? __________________________
44. Describe pedalfer clays (color, composition, etc.) ______________________________
Pedocal
45. What climate are pedocals found? ________________________________________
43. What geographic region of the U.S. are they found? __________________
43. What type of ecosystem are they found? __________________________
44. Describe pedocal clays (color, composition, etc.) ______________________________
Laterites
45. What climate are laterites found? ________________________________________
43. What geographic region (world) are they found? __________________
43. What type of ecosystem are they found? __________________________
44. Describe laterites clays (color, composition, etc.) ______________________________
45. Why is there so little organic matter in laterite soils? Provide 2 reasons.
46. Explain why laterites are the poorest soil for growing crops (agriculture)?
47. How long are crops usually successful when grown in laterite soils?
48. What happens to the soil after crops cannot be grown on the soil?
Soil Erosion
50. Why is topsoil important to humans?
51. What’s sheet erosion?
52. Why are soil erosion rates higher today than in the past?
53. How does removing plants (deforestation) effect soil erosion?
54. Before humans, rivers carried _________ ___________ kg of sediment out to sea. Today,
_____________________ kg of sediment are transported by rivers out to sea.
55. What type of erosion created the “Dust Bowl” of the Great Plains in the 1930s? What conditions
made this area vulnerable to this erosion?
56. What other factors can affect soil erosion (besides climate)?
57. How can excessive soil erosion lead to frequent dredging of rivers? What is dredging and why do
we need to do it?
Controlling Erosion
58. List 3 measures or activities that can help slow the rates of soil erosion.