Interpreting Fertilizer Labels Flashcards
7 cards from real CFA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Interpreting Fertilizer Labels flashcards as text
A fertilizer label reads 'guaranteed analysis: total nitrogen 10%.' What does 'guaranteed analysis' mean?
Answer: The minimum nutrient content the manufacturer promises to deliver
Guaranteed analysis is the minimum nutrient content the manufacturer is legally required to deliver, not an exact or average measurement.
On a fertilizer label, 'available phosphate (P2O5)' refers to which form of phosphorus?
Answer: Water-soluble plus citrate-soluble phosphate fractions
Available P2O5 includes both the water-soluble fraction and the citrate-soluble fraction, as both are considered plant-available.
A bag states 'derived from: urea, ammonium sulfate.' What does this tell the applicator?
Answer: The source materials from which nutrients were made
The 'derived from' statement identifies the raw ingredient sources, helping applicators understand nutrient forms and potential soil interactions.
Which label section specifies how much product to apply per 1,000 square feet for a lawn?
Answer: Application directions
Application directions (sometimes called directions for use) provide rate recommendations by area for various crop or turf situations.
A label shows 'sulfur (S) 12%.' In which of the following contexts is this information most critical?
Answer: When applying to soils already high in sulfur or to acid-sensitive crops
High sulfur content is most critical on soils already elevated in sulfur or when growing acid-sensitive crops, since sulfur oxidizes to sulfuric acid.
What does the term 'slowly available nitrogen' on a fertilizer label indicate?
Answer: Nitrogen released over time through microbial or chemical breakdown
Slowly available (or slow-release) nitrogen is released gradually through microbial decomposition or chemical hydrolysis, reducing leaching and burn risk.
A fertilizer label lists 'chlorine (Cl) not more than 3%.' Why is a maximum, rather than a minimum, stated for chlorine?
Answer: High chlorine can be toxic to chloride-sensitive crops, so a cap protects the grower
Chloride-sensitive crops like strawberries and some vegetables can be damaged by excessive chlorine, so the label caps it to assure growers the product is safe for those crops.