If a fertilizer is labeled 5-10-20, what percentage of potassium is in the fertilizer?

Fertilizers are labeled with a series of three numbers that represent the nutrient content in terms of nitrogen, phosphorus, and potassium, respectively. In the case of a fertilizer labeled 5-10-20, the last number, which is 20, indicates the percentage of potassium contained in that fertilizer.

So, in this example, the fertilizer contains 20% potassium. This means that if you were to have 100 pounds of this fertilizer, 20 pounds would be purely potassium. This labeling system helps farmers and gardeners understand what primary nutrients are available in their fertilization options, allowing them to make informed decisions about soil amendments and plant nutrient needs.

Thus, the percentage of potassium in the fertilizer is accurately represented by the last number in the sequence, confirming that the correct answer is 20%.