CCA Soil Management 2

Question 1

Which soil property best describes the ability of a soil to resist changes in pH when acids or bases are added?

Accepted Answer

Buffer capacity

Answer

Buffer capacity refers to a soil's ability to resist pH change when acids or bases are added, which is largely determined by organic matter and clay content.

Question 2

A soil has a bulk density of 1.35 g/cm³ and a particle density of 2.65 g/cm³. What is its total porosity?

Accepted Answer

49%

Answer

Total porosity = (1 - bulk density/particle density) × 100 = (1 - 1.35/2.65) × 100 ≈ 49%.

Question 3

Which tillage practice involves cutting and mixing residue into the top few inches of soil without full inversion?

Accepted Answer

Vertical tillage

Answer

Vertical tillage uses straight or slightly angled blades to cut and minimally mix residue in the surface layer without inverting the soil profile.

Question 4

Which soil order is characterized by an argillic or natric horizon and is commonly found in semi-arid grasslands?

Accepted Answer

Alfisols

Answer

Alfisols have an argillic horizon with moderate-to-high base saturation and are typically found under temperate forests or semi-arid grasslands.

Question 5

What is the primary mechanism by which nitrogen is lost from waterlogged soils?

Accepted Answer

Denitrification

Answer

Denitrification occurs when anaerobic bacteria convert nitrate (NO₃⁻) to nitrogen gases (N₂, N₂O) under waterlogged, oxygen-depleted conditions.

(CCA) Certified Crop Advisor Practice Test

(CCA) Certified Crop Advisor Practice Test

CCA Soil Management 2