CFA Label Interpretation and Calculations 2

Question 1

A fertilizer bag lists the guaranteed analysis as 10-5-8. What does the middle number (5) represent?

Accepted Answer

Available phosphate (P2O5) percentage

Answer

The middle number in the N-P-K analysis always represents available phosphate expressed as P2O5.

Question 2

A fertilizer label states 'Apply at 4 lbs per 1,000 sq ft.' How many pounds are needed for a 15,000 sq ft lawn?

Accepted Answer

60 lbs

Answer

4 lbs × (15,000 ÷ 1,000) = 4 × 15 = 60 lbs.

Question 3

What does the term 'slow-release nitrogen' on a fertilizer label indicate?

Accepted Answer

Nitrogen is converted by soil microbes or water over time

Answer

Slow-release nitrogen is formulated to break down gradually via microbial activity or hydrolysis, extending nutrient availability.

Question 4

A 50 lb bag of 20-0-10 fertilizer is applied to 5,000 sq ft. How many pounds of actual potash (K2O) are applied?

Accepted Answer

5 lbs

Answer

50 lbs × 10% K2O = 5 lbs of actual potash applied.

Question 5

Which section of a fertilizer label is legally required to list nutrient guarantees?

Accepted Answer

Guaranteed analysis

Answer

The 'Guaranteed Analysis' section is the legally mandated portion listing minimum nutrient percentages.

CFA Practice Test