Book 29, Question 110
What do the three numbers on a fertilizer bag mean?
Nitrogen helps leafy growth, phosphorus supports roots and flowers, and potassium helps plants stay healthy and resist stress.
The three numbers, such as 10-10-10, stand for nitrogen, phosphorus, and potassium, abbreviated N-P-K. The numbers tell the percent of each nutrient by weight. Different plants have different needs. Lawn fertilizers often have a lot of nitrogen.
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Quick answers
What do the three numbers on a fertilizer bag mean?
Complete fertilizers contain all three of the primary macronutrients.
Source: UMD
More fun facts
- By law, a slow-release fertilizer must contain at least one-third or 33 percent of the total amount of nitrogen in a slow-release form.
- Synthetic fertilizers do not burn plants if applied according to label instructions.
- Calculate the fertilizer ratio by dividing the numbers in the fertilizer grade by the lowest number in the fertilizer grade.
- The production of synthetic nitrogen fertilizers requires large amounts of natural gas, releasing carbon dioxide into the atmosphere, and contributing to climate change.