How much nitrogen is contained in a 50-lb bag of 20-10-5 fertilizer?

To determine how much nitrogen is contained in a 50-lb bag of fertilizer with an N-P-K ratio of 20-10-5, it is essential to understand what the numbers in the ratio represent. The first number indicates the percentage of nitrogen in the fertilizer. In this case, the fertilizer is 20% nitrogen.

To find the actual amount of nitrogen, you calculate 20% of the total weight of the fertilizer bag. This can be done using the following formula:

Amount of nitrogen = (percentage of nitrogen / 100) × total weight of fertilizer.

Substituting the values:

Amount of nitrogen = (20 / 100) × 50 lbs = 0.20 × 50 = 10 lbs.

Thus, a 50-lb bag of 20-10-5 fertilizer contains 10 lbs of nitrogen, which aligns with the information provided. This calculation highlights the significance of understanding the composition of fertilizers to apply the correct amount of nutrients to plants, which is crucial for optimal growth and health in horticulture.