What is Sodium ppm and meq/100g?
- Sodium ppm (parts per million) means how many parts of sodium are present in one million parts of soil. It is like saying “how much sodium is there in the soil” in a very small amount.
- Sodium meq/100g (milliequivalents per 100 grams of soil) tells us the amount of sodium based on its chemical charge and weight, which helps understand how sodium affects soil properties, especially soil reaction and nutrient balance.
Why convert ppm to meq/100g?
- Sodium in meq/100g shows how sodium interacts with other nutrients and soil particles.
- It helps decide if the sodium level is harmful or suitable for crops.
- ppm only tells the amount, but meq/100g tells the effect and helps manage soil better.
How to convert Sodium ppm to Sodium meq/100g?
- Know the Sodium atomic weight: Sodium (Na) atomic weight = 23 g/mol.
- Sodium charge: Sodium has a charge of +1.
- Formula:
Sodium meq/100g=Sodium ppm×10Atomic weight of Sodium
Explanation:
- Multiply Sodium ppm by 10 because ppm is mg/kg, and we want mg/100g (which is 1/10th kg).
- Divide by atomic weight (23) to convert mg to milliequivalents.
Example calculation:
If soil has 230 ppm Sodium:
Sodium meq/100g=230×10/23=2300/23=100 meq/100g
Summary:
| Step | Action |
|---|---|
| Start with Sodium ppm | Given value |
| Multiply by 10 | Convert mg/kg to mg/100g |
| Divide by 23 | Convert mg to meq (atomic weight) |
This will give you Sodium in meq/100g soil, useful for soil testing and better crop management.
You can find more agriculture conversion calculators here.