Magnesium Sulphate Heptahydrate (MgSO₄·7H₂O), commonly known as Epsom Salt, provides 9.9% elemental magnesium and 13% sulphur. It is the most widely used magnesium fertilizer globally due to its high solubility (710 g/L at 20°C), low cost and dual nutrient value.
Magnesium is the central atom of the chlorophyll molecule — each chlorophyll molecule contains one magnesium atom. Without adequate magnesium, chlorophyll synthesis is impaired and photosynthesis rate declines. Magnesium is also essential for phosphorus metabolism (ATP synthesis), protein synthesis (ribosome stability) and carbohydrate partitioning (loading of sugars into phloem).
Magnesium Sulphate is particularly effective as a foliar spray when soil application is not practical or when rapid correction is needed. The high solubility makes it suitable for all spray equipment at concentrations up to 1.5–2% (15–20 g/L) without risk of phytotoxicity at recommended rates.
| Magnesium (MgO) | 16.0% min (as MgO) |
| Magnesium (Mg) | 9.9% min |
| Sulphur (S) | 13.0% min |
| Chemical Formula | MgSO₄·7H₂O |
| Moisture | As heptahydrate (naturally occurring) |
| pH (1% solution) | 6.0–7.0 |
| Water Solubility | 710 g/L at 20°C |
| Heavy Metals | <5 ppm |
| Foliar Spray | 5–10 g per litre of water |
| Drip Fertigation | 3–5 kg per acre |
| Soil Application | 15–20 kg per acre |
| Frequency | Every 14–21 days or at deficiency symptom |
Get Instant Quote
For Magnesium Sulphate Heptahydrate (Epsom Salt). Response within 2 hours.