Texas FFA Nursery Landscape Practice Exam

What type of fertilizer ratio, such as 5-10-15, indicates the percentage of nitrogen?

1. A. First number

2. B. Second number

3. C. Third number

4. D. None of these

The correct answer is: A. First number

The first number in a fertilizer ratio, such as 5-10-15, represents the percentage of nitrogen (N) in the fertilizer formulation. Fertilizers are typically labeled in a ratio format indicating the three primary nutrient components: nitrogen, phosphorus (P), and potassium (K). In the example of a 5-10-15 ratio, the first number (5) indicates that 5% of the total weight of the fertilizer is nitrogen. This nutrient is crucial for promoting vigorous growth in plants and is essential for leaf development and overall plant health. Phosphorus, indicated by the second number (10), supports root development and flowering, while potassium, represented by the third number (15), is important for overall plant health, disease resistance, and drought tolerance. Recognizing that the first number in the ratio signifies nitrogen helps in selecting the appropriate fertilizer for specific gardening and landscape projects where nitrogen is desired for optimal plant growth.