Description :
The values in an NPK fertilizer label are related to the concentrations (by weight) of phosphorus and potassium elements as follows:
- P
2O
5 consists of 56.4% elemental oxygen and 43.6% elemental phosphorus by weight. Therefore, the elemental phosphorus percentage of a fertilizer is 0.436 times its P value. - K
2O consists of 17% oxygen and 83% elemental potassium by weight. Therefore, the elemental potassium percentage is 0.83 times the K value.
The N value in NPK labels represents actual percentage of nitrogen element by weight, so it does not need to be converted.
So, for example, an 18−51−20 fertilizer contains by weight
- 18% elemental nitrogen,
- 0.436 × 51 = 22% elemental phosphorus, and
- 0.83 × 20 = 17% elemental potassium.
As another example, the fertilizer sylvite is a naturally occurring mineral consisting mostly of potassium chloride, KCl. Pure potassium chloride contains one potassium atom (whose atomic mass is 39.09 g/mol) for every chlorine atom (whose atomic mass is 35.45 g/mol). Therefore, pure KCl is 39.09/(39.09 + 35.45) = 52% potassium and 48% chlorine by weight. Its K value is therefore 52/0.83 = 63; that is, a fertilizer that gets all its potassium from K
2O and has the same potassium contents as pure KCl would have to be 63% K
2O. Pure KCl fertilizer would thus be labeled 0-0-63. Since sylvite contains other compounds that contribute no N, P, or K, it is usually labeled 0-0-60.
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Additional Information:
- Item Code: 04
- Production Capacity: 100 MT
- Delivery Time: IMMIDIATE
- Packaging Details: 50 KG HDPE BAG WITH INNER LDPE LINER
