CFA Nutrient Sources and Management 2

Question 1

Which fertilizer material is considered an organic nitrogen source because it releases nitrogen through microbial decomposition?

Accepted Answer

Feather meal

Answer

Urea

Answer

Ammonium nitrate

Answer

Calcium nitrate

Question 2

A fertilizer label reads 10-20-10. What is the percentage of phosphate (P₂O₅) in this product?

Accepted Answer

20%

Answer

10%

Answer

30%

Answer

40%

Question 3

Which form of phosphorus do plant roots actually absorb from the soil solution?

Accepted Answer

Orthophosphate (H₂PO₄⁻ or HPO₄²⁻)

Answer

Polyphosphate (P₃O₁₀)

Answer

Apatite mineral form

Answer

Organic phytate form

Question 4

Sulfur-coated urea releases nitrogen more slowly than regular urea primarily because:

Accepted Answer

The coating must degrade before water can dissolve the urea

Answer

Sulfur increases soil pH, slowing nitrification

Answer

Urea inside the coating has lower nitrogen content

Answer

Sulfur reacts with urea to form a stable compound

Question 5

When manure is surface-applied without incorporation, the greatest nutrient loss risk is:

Accepted Answer

Ammonia volatilization from nitrogen

Answer

Potassium leaching

Answer

Phosphorus volatilization

Answer

Sulfur oxidation

Question 6

Which potassium fertilizer also supplies sulfur, making it useful on sulfur-deficient soils?

Accepted Answer

Sulfate of potash (K₂SO₄)

Answer

Muriate of potash (KCl)

Answer

Potassium nitrate (KNO₃)

Answer

Potassium carbonate (K₂CO₃)

Question 7

A soil test recommends 60 lb P₂O₅/acre. If triple superphosphate (0-46-0) is used, approximately how many pounds per acre are needed?

Accepted Answer

130 lb/acre

Answer

28 lb/acre

Answer

60 lb/acre

Answer

276 lb/acre