Soil Science & Analysis Flashcards

Which soil texture class has the highest water-holding capacity per unit volume?

Answer: Clay

Clay soils have the highest water-holding capacity due to their large surface area and abundant micropores.

The Unified Soil Classification System (USCS) is most commonly used in which fisheries-related context?

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.

A soil with a bulk density of 1.8 g/cm³ compared to one at 1.2 g/cm³ is likely to be:

Answer: More compacted with reduced porosity

Higher bulk density indicates greater compaction and less pore space, limiting water infiltration and root penetration.

Which of the following best describes the role of cation exchange capacity (CEC) in pond management?

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.

Which soil horizon is most important to sample when evaluating nutrient status for new pond construction?

Answer: A horizon

The A horizon (topsoil) contains the highest organic matter and nutrient concentrations most relevant to initial pond fertility.

Gleying in soil profiles is indicated by what color pattern and what does it imply for fisheries managers?

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.

When conducting a pond soil fertility assessment, a low soil pH of 4.5 would most likely indicate the need for:

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.