Explanation for Farmer: Magnesium Meq/100g to ppm
- Magnesium (Mg) is a nutrient in the soil that plants need to grow.
- Sometimes, soil test reports show Magnesium in Meq/100g (milliequivalents per 100 grams of soil).
- Other times, you might want to understand or compare it in ppm (parts per million), which is like mg/kg of soil.
- To understand your soil nutrient levels better or to follow fertilizer recommendations, converting Meq/100g to ppm is useful.
What is Meq/100g and ppm?
- Meq/100g: This shows the charge-based amount of Magnesium in 100 grams of soil.
- ppm: This shows the weight (mass) of Magnesium in milligrams per kilogram of soil (mg/kg).
How to convert Magnesium Meq/100g to ppm
Step 1: Know the formula
ppm Mg=Meq/100g Mg×Equivalent weight of Mg×10
Step 2: Equivalent weight of Magnesium
- Atomic weight of Mg = 24.3
- Charge of Mg ion = +2
- Equivalent weight = Atomic weight / Charge = 24.3/2=12.15
Step 3: Apply the formula
ppm Mg=Meq/100g Mg×12.15×10=Meq/100g Mg×121.5
Example:
If your soil test shows Magnesium = 0.5 Meq/100g,
ppm Mg=0.5×121.5=60.75 ppm
Summary:
| Unit | Meaning |
|---|---|
| Meq/100g | Milliequivalents per 100 g soil |
| ppm | mg of Mg per kg soil (mg/kg) |
Conversion:
ppm Mg=Meq/100g Mg×121.5
Use this simple multiplication to convert your soil test Magnesium values from Meq/100g to ppm for easier understanding.
You can find more agriculture conversion calculators here.