CFA Soil Properties and Testing 3

Question 1

Which soil horizon is typically where the most weathering, leaching, and organic matter accumulation occurs?

Accepted Answer

A horizon

Answer

The A horizon (topsoil) is the zone of maximum organic matter accumulation and biological activity.

Question 2

Soil with a high clay content tends to have what effect on fertilizer application timing?

Accepted Answer

Nutrients are held longer, allowing single large applications

Answer

Clay soils have high CEC and hold cations longer, reducing leaching and allowing less-frequent nutrient applications.

Question 3

A grower applies lime to raise soil pH. Which property of lime determines how quickly it reacts in soil?

Accepted Answer

Fineness (particle size)

Answer

Finer lime particles have greater surface area and react faster with soil acidity than coarser particles.

Question 4

The term 'cation exchange capacity' (CEC) describes:

Accepted Answer

The total negative charge sites available to hold positively charged ions

Answer

CEC measures the quantity of cations a soil can adsorb and retain on its negatively charged surfaces.

Question 5

Which soil property most directly determines the buffering capacity against pH change?

Accepted Answer

CEC and organic matter content

Answer

Soils with high CEC and organic matter resist pH changes because they can adsorb or release H⁺ ions.

CFA Practice Test