The middle number in N-P-K labeling refers to which nutrient?

The middle number in N-P-K labeling refers to which nutrient?

• A. Phosphorus
• B. Nitrogen
• C. Potassium
• D. Calcium

Answer: (A)

Phosphorus. The middle number in N-P-K labeling represents the phosphorus content of the fertilizer. Phosphorus is crucial for root development, energy transfer within the plant, and the formation of flowers and fruits. The first number is nitrogen, which mainly drives leafy growth; the last number is potassium, which supports overall vigor and stress tolerance. Fertilizer labels show these three nutrients in that order as percentages by weight, with phosphorus sometimes shown as P (or historically as P2O5). Calcium is not part of the standard N-P-K trio.

Phosphorus. The middle number in N-P-K labeling represents the phosphorus content of the fertilizer. Phosphorus is crucial for root development, energy transfer within the plant, and the formation of flowers and fruits. The first number is nitrogen, which mainly drives leafy growth; the last number is potassium, which supports overall vigor and stress tolerance. Fertilizer labels show these three nutrients in that order as percentages by weight, with phosphorus sometimes shown as P (or historically as P2O5). Calcium is not part of the standard N-P-K trio.