comparison between Kieserite (MgSO₄·H₂O) and Magnesium Sulfate Heptahydrate (MgSO₄·7H₂O)
Kieserite (MgSO₄·H₂O) and Magnesium Sulfate Heptahydrate (MgSO₄·7H₂O) in terms of product characteristics and agricultural application:
✅ Kieserite vs Magnesium Sulfate Heptahydrate
| Aspect | Kieserite (MgSO₄·H₂O) | Magnesium Sulfate Heptahydrate (MgSO₄·7H₂O) |
|---|---|---|
| Chemical Formula | Magnesium Sulfate Monohydrate (MgSO₄·H₂O) | Magnesium Sulfate Heptahydrate (MgSO₄·7H₂O) |
| MgO Content | ~25–27% | ~16% |
| S (Sulfur) Content | ~20% | ~13% |
| Appearance | Grayish/white granules or powder | White crystals (like Epsom salt) |
| Solubility in Water | Moderate (slower to dissolve) | Highly soluble (fast-dissolving) |
| Granule Hardness | High – good for bulk blending | Soft – may cake in humid conditions |
| Hygroscopicity | Low – stable in humid environments | High – absorbs moisture easily |
| Bulk Density | Higher | Lower |
| Storage Stability | Excellent – long shelf life | Fair – requires sealed packaging |
✅ Application Differences
| Application Aspect | Kieserite | Heptahydrate (MgSO₄·7H₂O) |
|---|---|---|
| Best Use | Soil application, bulk fertilizer blending | Foliar spray, fertigation, hydroponics |
| Release Speed | Medium (slower release) | Fast-acting, instantly available |
| Recommended for | Acidic soils, long-term magnesium replenishment | Quick correction of Mg or S deficiency |
| Compatibility | Compatible with granular blends (e.g. NPK) | Compatible with most soluble fertilizers and sprays |
| Application Methods | Broadcast, side dressing, base application | Foliar spray, drip irrigation, seed soak, hydroponic use |
✅ Summary: Which One to Use?
- Choose Kieserite (MgSO₄·H₂O) when:
- You need longer-lasting magnesium supply
- You’re blending with granular or slow-release fertilizers
- The soil is acidic and you’re applying directly to the field
- Choose Heptahydrate (MgSO₄·7H₂O) when:
- You need quick nutrient correction
- You’re using foliar spray, fertigation, or hydroponics
- Precision and fast nutrient uptake is essential
Rongqing Chemical
Rongqing Chemical Co. Ltd, established in 1991, is a China-based kieserite Manufacturer & Exporter. Located in Yingkou Liaoning -the China magnesium We focus on kieserite,magnesium sulfate
