Label Interpretation and Calculations Flashcards

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?

Answer: 12 oz

2 oz per gallon × 6 gallons = 12 oz of concentrate.

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?

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.

Which label element tells the applicator the maximum number of applications allowed per year?

Answer: Directions for use

Application frequency limits and annual maximums are found in the Directions for Use section of the label.

A blended fertilizer label shows 16-4-8 plus 1% iron. How many lbs of iron are in a 40 lb bag?

Answer: 0.4 lbs

40 lbs × 1% = 40 × 0.01 = 0.4 lbs of iron.

When calculating fertilizer application rates, why must applicators distinguish between 'product rate' and 'nutrient rate'?

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.

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?

Answer: 125 lbs

500 lbs/acre × 0.25 acres = 125 lbs.

A label requires a buffer zone of 25 feet from any water body before application. This instruction appears under which label section?

Answer: Environmental hazards / precautionary statements

Buffer zone requirements and environmental protections are listed under the Precautionary or Environmental Hazards section of the label.