CFA Soil Science and Testing 2

Question 1

A soil test reports a cation exchange capacity (CEC) of 25 meq/100g. What does this indicate about the soil's nutrient-holding ability?

Accepted Answer

High nutrient-holding capacity

Answer

A CEC of 25 meq/100g is considered high, meaning the soil can hold large amounts of positively charged nutrients like calcium, magnesium, and potassium.

Question 2

Which soil texture class typically has the highest water-holding capacity?

Accepted Answer

Clay loam

Answer

Clay loam soils have a high proportion of fine particles with large surface area, allowing them to retain significantly more water than coarser-textured soils.

Question 3

When a soil test shows high phosphorus levels, a fertilizer applicator should:

Accepted Answer

Reduce or eliminate phosphorus fertilizer applications

Answer

High soil phosphorus levels indicate no additional phosphorus is needed; over-application leads to runoff pollution and wasted resources.

Question 4

What is the primary purpose of measuring soil electrical conductivity (EC)?

Accepted Answer

To estimate soil salinity and ion concentration

Answer

Soil EC measures the ability of soil to conduct electrical current, which directly correlates with dissolved salt concentration and overall ion content.

Question 5

A soil with a high silt content is most prone to which problem?

Accepted Answer

Surface crusting and reduced water infiltration

Answer

Silt particles are small but lack the cohesion of clay, making silt-dominated soils prone to surface crusting when wetted and dried repeatedly.

CFA Practice Test

CFA Practice Test

CFA Soil Science and Testing 2