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

The exact nutrient content measured in every bag

Answer

The maximum nutrient content allowed by law

Answer

An estimate based on raw material averages

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

Total phosphorus in the product regardless of solubility

Answer

Phosphorus expressed as elemental P in pounds

Answer

Only the phosphorus that dissolves in water

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 nitrogen percentage split between forms

Answer

The order of application recommended

Answer

The soil types for which the product is approved

Question 4

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

Accepted Answer

Application directions

Answer

Guaranteed analysis

Answer

Precautionary statements

Answer

Net weight statement

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

When calculating the cost per pound of nitrogen

Answer

When determining whether irrigation is required

Answer

When checking for phosphorus interaction with iron

Question 6

What does the term 'slowly available nitrogen' on a fertilizer label indicate?

Accepted Answer

Nitrogen released over time through microbial or chemical breakdown

Answer

Nitrogen that requires tillage to become available

Answer

Nitrogen that is only available in alkaline soils

Answer

Nitrogen that has been stabilized with a urease inhibitor only

Question 7

A fertilizer label lists 'chlorine (Cl) not more than 3%.' Why is a maximum, rather than a minimum, stated for chlorine?

Accepted Answer

High chlorine can be toxic to chloride-sensitive crops, so a cap protects the grower

Answer

Chlorine is a secondary macronutrient that must be maximized

Answer

Chlorine is regulated by EPA as a hazardous substance above 3%

Answer

Labels are only required to state maximums for micronutrients