CFA Interpreting Fertilizer Labels 2

Question 1

A fertilizer label reads 'guaranteed analysis: total nitrogen 10%.' What does 'guaranteed analysis' mean?

Accepted Answer

The minimum nutrient content the manufacturer promises to deliver

Answer

Guaranteed analysis is the minimum nutrient content the manufacturer is legally required to deliver, not an exact or average measurement.

Question 2

On a fertilizer label, 'available phosphate (P2O5)' refers to which form of phosphorus?

Accepted Answer

Water-soluble plus citrate-soluble phosphate fractions

Answer

Available P2O5 includes both the water-soluble fraction and the citrate-soluble fraction, as both are considered plant-available.

Question 3

A bag states 'derived from: urea, ammonium sulfate.' What does this tell the applicator?

Accepted Answer

The source materials from which nutrients were made

Answer

The 'derived from' statement identifies the raw ingredient sources, helping applicators understand nutrient forms and potential soil interactions.

Question 4

Which label section specifies how much product to apply per 1,000 square feet for a lawn?

Accepted Answer

Application directions

Answer

Application directions (sometimes called directions for use) provide rate recommendations by area for various crop or turf situations.

Question 5

A label shows 'sulfur (S) 12%.' In which of the following contexts is this information most critical?

Accepted Answer

When applying to soils already high in sulfur or to acid-sensitive crops

Answer

High sulfur content is most critical on soils already elevated in sulfur or when growing acid-sensitive crops, since sulfur oxidizes to sulfuric acid.

CFA Practice Test

CFA Practice Test

CFA Interpreting Fertilizer Labels 2