CFP Soil Science & Analysis 2 — Questions and Answers
Question 1: Which soil texture class has the highest water-holding capacity per unit volume?
- Sandy loam
- Silt loam
- Clay (Correct answer)
- Loamy sand
Correct answer: Clay
Clay soils have the highest water-holding capacity due to their large surface area and abundant micropores.
Question 2: The Unified Soil Classification System (USCS) is most commonly used in which fisheries-related context?
- Describing pond bottom sediments for production
- Engineering site assessments for dam and impoundment construction (Correct answer)
- Classifying riparian buffer soil types
- Quantifying organic matter in wetland soils
Correct answer: Engineering site assessments for dam and impoundment construction
USCS is an engineering classification system primarily used when designing and constructing dams, levees, and pond embankments.
Question 3: A soil with a bulk density of 1.8 g/cm³ compared to one at 1.2 g/cm³ is likely to be:
- More fertile and productive
- More compacted with reduced porosity (Correct answer)
- Higher in organic matter
- Better suited for aquatic plant growth
Correct answer: More compacted with reduced porosity
Higher bulk density indicates greater compaction and less pore space, limiting water infiltration and root penetration.
Question 4: Which of the following best describes the role of cation exchange capacity (CEC) in pond management?
- It determines the rate of sediment settling
- It indicates the soil's ability to retain and supply nutrients to pond water (Correct answer)
- It measures the rate of organic matter decomposition
- It controls the soil's infiltration rate
Correct answer: It indicates the soil's ability to retain and supply nutrients to pond water
CEC reflects the soil's capacity to hold positively charged nutrients like calcium, magnesium, and potassium, influencing pond fertility.
Question 5: Which soil horizon is most important to sample when evaluating nutrient status for new pond construction?
- O horizon
- A horizon (Correct answer)
- B horizon
- C horizon
Correct answer: A horizon
The A horizon (topsoil) contains the highest organic matter and nutrient concentrations most relevant to initial pond fertility.
Question 6: Gleying in soil profiles is indicated by what color pattern and what does it imply for fisheries managers?
- Red mottling; well-drained soils with high iron content
- Gray or blue-green colors; prolonged waterlogging and reducing conditions (Correct answer)
- Black streaks; high charcoal content from past fires
- White horizons; calcium carbonate accumulation
Correct answer: Gray or blue-green colors; prolonged waterlogging and reducing conditions
Gleying produces gray, blue, or green colors from iron reduction under anaerobic, waterlogged conditions, indicating a high water table.
Question 7: When conducting a pond soil fertility assessment, a low soil pH of 4.5 would most likely indicate the need for:
- Sulfur application to lower alkalinity
- Agricultural limestone application to raise pH (Correct answer)
- Potassium chloride to improve ionic strength
- Phosphate reduction to prevent algal blooms
Correct answer: Agricultural limestone application to raise pH
Acidic pond soils require liming with agricultural limestone (CaCO₃) to raise pH into the optimal range for productivity.
CFP Soil Science & Analysis 2
Which soil texture class has the highest water-holding capacity per unit volume?