CFA Label Interpretation and Calculations 3 — Questions and Answers
Question 1: A liquid fertilizer label states the concentration is 4-0-8 at a dilution rate of 2 oz per gallon. An applicator mixes 6 gallons. How many oz of concentrate are used?
- 6 oz
- 8 oz
- 12 oz (Correct answer)
- 24 oz
Correct answer: 12 oz
2 oz per gallon × 6 gallons = 12 oz of concentrate.
Question 2: A fertilizer is labeled 30-0-4 with a recommended rate of 1 lb nitrogen per 1,000 sq ft. How many lbs of product per 1,000 sq ft are needed?
- 1.5 lbs
- 2.0 lbs
- 3.0 lbs
- 3.33 lbs (Correct answer)
Correct answer: 3.33 lbs
To deliver 1 lb N from a 30% N product: 1 ÷ 0.30 = 3.33 lbs of product per 1,000 sq ft.
Question 3: Which label element tells the applicator the maximum number of applications allowed per year?
- Guaranteed analysis
- Directions for use (Correct answer)
- Signal word
- Net weight
Correct answer: Directions for use
Application frequency limits and annual maximums are found in the Directions for Use section of the label.
Question 4: A blended fertilizer label shows 16-4-8 plus 1% iron. How many lbs of iron are in a 40 lb bag?
- 0.4 lbs (Correct answer)
- 0.8 lbs
- 1.0 lbs
- 4.0 lbs
Correct answer: 0.4 lbs
40 lbs × 1% = 40 × 0.01 = 0.4 lbs of iron.
Question 5: When calculating fertilizer application rates, why must applicators distinguish between 'product rate' and 'nutrient rate'?
- Product rate applies only to liquid fertilizers
- Nutrient rate is always expressed in ounces, not pounds
- Applying product rate as nutrient rate can over- or under-apply nutrients (Correct answer)
- The two rates are legally required to be identical on labels
Correct answer: Applying product rate as nutrient rate can over- or under-apply nutrients
Confusing product rate with nutrient rate leads to incorrect application because the actual nutrient concentration varies by product.
Question 6: A fertilizer label specifies a pre-plant soil incorporation rate of 500 lbs per acre. How many lbs are needed for a 0.25-acre plot?
- 100 lbs
- 125 lbs (Correct answer)
- 150 lbs
- 200 lbs
Correct answer: 125 lbs
500 lbs/acre × 0.25 acres = 125 lbs.
Question 7: A label requires a buffer zone of 25 feet from any water body before application. This instruction appears under which label section?
- Guaranteed analysis
- Environmental hazards / precautionary statements (Correct answer)
- Net contents
- Ingredient disclosure
Correct answer: Environmental hazards / precautionary statements
Buffer zone requirements and environmental protections are listed under the Precautionary or Environmental Hazards section of the label.
CFA Label Interpretation and Calculations 3
A liquid fertilizer label states the concentration is 4-0-8 at a dilution rate of 2 oz per gallon.
An applicator mixes 6 gallons.
How many oz of concentrate are used?