What percentage of phosphate does a 21-7-14 fertilizer contain?

In a fertilizer formulation like 21-7-14, the numbers signify the percentage of three vital nutrients: nitrogen (N), phosphorus (P), and potassium (K), respectively. These percentages represent the amount of each nutrient in the fertilizer by weight.

The first number, 21, corresponds to the nitrogen content, which is 21 percent. The second number, 7, indicates the phosphorus content, which is 7 percent. Lastly, the third number, 14, refers to the potassium content, which is 14 percent.

Given this breakdown, the phosphorus content of the fertilizer is accurately represented by the second number, which is 7 percent. Thus, the correct answer is 7 percent. This is important for understanding the nutrient profile of fertilizers, as it helps determine how much of each nutrient is being supplied to plants for optimal growth.