CFA Soil Properties and Testing 2

Question 1

A soil sample has a bulk density of 1.6 g/cm³. Which condition does this most likely indicate?

Accepted Answer

Highly compacted soil with restricted root growth

Answer

Loose, well-aerated sandy loam

Answer

Organic-rich topsoil with good structure

Answer

Freshly tilled soil with high porosity

Question 2

Which soil textural class holds the most plant-available water while still draining adequately?

Accepted Answer

Loam

Answer

Sand

Answer

Clay

Answer

Silt

Question 3

When interpreting a soil test report, a base saturation of potassium (K) at 5% is considered:

Accepted Answer

Adequate for most crops

Answer

Deficient for most crops

Answer

Excessive and potentially toxic

Answer

Irrelevant without knowing CEC

Question 4

Which extraction method is most commonly used to assess plant-available phosphorus in neutral to alkaline soils in the western US?

Accepted Answer

Olsen (sodium bicarbonate)

Answer

Mehlich-3

Answer

Bray P-1

Answer

Morgan

Question 5

Soil organic matter is most accurately measured in a laboratory by:

Accepted Answer

Loss-on-ignition (LOI) or Walkley-Black wet oxidation

Answer

Munsell color chart comparison

Answer

Electrical conductivity meter

Answer

Penetrometer resistance readings

Question 6

A soil pH of 5.2 would most likely cause deficiency of which nutrient in corn production?

Accepted Answer

Phosphorus (P)

Answer

Iron (Fe)

Answer

Molybdenum (Mo)

Answer

Manganese (Mn)

Question 7

What does a low soil electrical conductivity (EC) reading indicate in a field used for vegetable production?

Accepted Answer

Low soluble salt concentration, possible nutrient deficiency risk

Answer

High salinity stress risk

Answer

Adequate nutrient levels for crop growth

Answer

Excessive organic matter decomposition