Soil Science | Soil Formation Questions and Answers Latest Update
What are the four stages of decomposing organic material?
ANSWER
Fibric - Beginning stage of decomposition (Fibrous Peat)
Folic - Partly decomposed (Leaf mold)
Hemic - Half decomposed (Muck)
Sapric - Completely decomposed (Rotten muck)
What is the dominating factor acting on the Parent Material?
ANSWER-Climate (Temperature and precipitation)
What is the direct influence physically on the Parent Material from temperature?
ANSWER-Freezing and thawing
What are the two direct influences physically on the Parent Material from precipitation? – ANSWER
Wetting
Drying
What are the three different types of climate that influence vegetation?
ANSWER
Humid - Forest
Semiarid - Grassland
Arid – Desert
What is the necessary annual rainfall needed to classify each type of climate?
ANSWER
30" - Forest (Humid)
10" - 30" - Grassland (Semiarid)
< 10" - Desert (Arid)
What are the four ways lots of water speeds up soil formation?
ANSWER
Leaching
Eluviation
, Grinding
Freeze/Thaw
What are the four signs that the soil is lacking water?
ANSWER
Slow chemical reaction
Light color soil
Natural salts are not leached
Shallow soil
What is Sodic Soil? ANSWER-Soil with high salt content
What is Shallow Soil? ANSWER-Less depth of horizons A and B
How does temperature affect soil formation?
ANSWER-High temps cause decomposition to speed up as low temps cause decomposition to slow
down. (Soil forms quicker in Georgia than it does in Michigan)
What are the two direct effects on soil with little rainfall?
ANSWER
Shallow soil
Accumulation of soluble salts
What are the three direct effects on soil with high rainfall?
ANSWER
Acid soil due to intense weathering and leaching.
Erosion of soil on slopes.
Deposition of soil material downstream.
(Each of these affects are intensified in climates where soil doesn't freeze)
What are the two characteristics of a soil profile taken in a grassy area?
ANSWER
Dark A horizon due to the depth of the grass roots.
Neutral to alkaline soil due to basic cations being recycled to offset leaching.
What are the five characteristics of a soil profile taken in the forest?
ANSWER
What are the four stages of decomposing organic material?
ANSWER
Fibric - Beginning stage of decomposition (Fibrous Peat)
Folic - Partly decomposed (Leaf mold)
Hemic - Half decomposed (Muck)
Sapric - Completely decomposed (Rotten muck)
What is the dominating factor acting on the Parent Material?
ANSWER-Climate (Temperature and precipitation)
What is the direct influence physically on the Parent Material from temperature?
ANSWER-Freezing and thawing
What are the two direct influences physically on the Parent Material from precipitation? – ANSWER
Wetting
Drying
What are the three different types of climate that influence vegetation?
ANSWER
Humid - Forest
Semiarid - Grassland
Arid – Desert
What is the necessary annual rainfall needed to classify each type of climate?
ANSWER
30" - Forest (Humid)
10" - 30" - Grassland (Semiarid)
< 10" - Desert (Arid)
What are the four ways lots of water speeds up soil formation?
ANSWER
Leaching
Eluviation
, Grinding
Freeze/Thaw
What are the four signs that the soil is lacking water?
ANSWER
Slow chemical reaction
Light color soil
Natural salts are not leached
Shallow soil
What is Sodic Soil? ANSWER-Soil with high salt content
What is Shallow Soil? ANSWER-Less depth of horizons A and B
How does temperature affect soil formation?
ANSWER-High temps cause decomposition to speed up as low temps cause decomposition to slow
down. (Soil forms quicker in Georgia than it does in Michigan)
What are the two direct effects on soil with little rainfall?
ANSWER
Shallow soil
Accumulation of soluble salts
What are the three direct effects on soil with high rainfall?
ANSWER
Acid soil due to intense weathering and leaching.
Erosion of soil on slopes.
Deposition of soil material downstream.
(Each of these affects are intensified in climates where soil doesn't freeze)
What are the two characteristics of a soil profile taken in a grassy area?
ANSWER
Dark A horizon due to the depth of the grass roots.
Neutral to alkaline soil due to basic cations being recycled to offset leaching.
What are the five characteristics of a soil profile taken in the forest?
ANSWER
