Potassium Magnesium Sulfate (Langbeinite)
Also known as: Langbeinite, Sulfate of Potash Magnesia, K-Mag, Sul-Po-Mag Chemical Formula: K₂Mg₂(SO₄)₃ (or K₂SO₄ · 2MgSO₄) Typical Grade: 0-0-22 + 11% Mg + 22% S
Potassium Magnesium Sulfate, commercially known as Langbeinite, is a naturally occurring multi-nutrient fertilizer that simultaneously supplies three essential plant nutrients — Potassium (K), Magnesium (Mg), and Sulfur (S) — in a single product. It is chloride-free and has a low salt index, making it particularly valuable for high-value and chloride-sensitive crops.
Langbeinite is mined from natural mineral deposits, washed, crushed, and screened into granular form. Its unique mineral structure releases nutrients steadily in the soil.
Technical Specifications
| Parameter | Unit | Typical / Standard Value |
|---|---|---|
| Potassium Oxide (K₂O) | % | 21–22 min |
| Magnesium (Mg) | % | 10–11 (≈ 18% MgO) |
| Sulfur (S) | % | 21–22 |
| Chloride (Cl) | % | Low (typically < 2.5–3.0 max) |
| Moisture | % | Low (generally < 1%) |
| Appearance | — | Pinkish, reddish, grey or white granules/crystals |
| Water Solubility | — | Moderately soluble (slower release than pure SOP or MOP) |
| Salt Index | — | Low |
| Bulk Density (approx.) | kg/m³ | 1,300–1,500 |
Typical Physical Properties
- Granular form suitable for broadcasting and blending
- Neutral pH effect in soil
- Nutrients present in water-soluble sulfate form
- Uniform nutrient distribution because K, Mg, and S are contained in the same particle
Key Benefits
- Three nutrients in one product — Supplies potassium, magnesium, and sulfur simultaneously, simplifying application and ensuring balanced nutrition.
- Chloride-free — Safe for chloride-sensitive crops (potatoes, grapes, strawberries, tobacco, certain fruits and vegetables).
- Low salt index — Reduces risk of fertilizer burn and soil salinity compared to high-chloride fertilizers.
- Improves crop quality — Potassium enhances size, colour, and sweetness; magnesium supports chlorophyll formation and photosynthesis; sulfur aids protein and oil synthesis and flavour development.
- Corrects multiple deficiencies — Especially useful in soils low in magnesium and/or sulfur.
- Steady nutrient release — Moderately soluble, providing sustained availability.
Recommended Applications
Ideal for high-value and chloride-sensitive crops:
- Fruits: Apples, citrus, grapes, berries, strawberries
- Vegetables: Potatoes, tomatoes, carrots, lettuce, onions
- Nuts: Almonds, pistachios
- Other: Tobacco, coffee, tea, and many horticultural crops
Particularly valuable when:
- Magnesium deficiency is present or likely
- Sulfur is also required
- Chloride must be avoided
- Balanced multi-nutrient feeding is desired
Application Methods:
- Soil application (broadcast or banded) before planting or as side-dressing
- Blending with nitrogen or phosphorus fertilizers for custom mixes
- Suitable for organic systems (certain grades are OMRI-listed or organically approved)
Rates should be based on soil tests, crop requirements, and the need for magnesium/sulfur (often applied to meet Mg or S needs rather than the full potassium requirement).
Packaging Options
- 50 kg polypropylene bags
- 1,000 kg jumbo bags (FIBC)
- Bulk delivery available for large-scale use
Storage & Handling Recommendations
- Store in a cool, dry, well-ventilated warehouse protected from moisture.
- Keep bags sealed and stacked on pallets to prevent caking.
- Handle with standard personal protective equipment to avoid dust inhalation.
Summary
Potassium Magnesium Sulfate (Langbeinite) is a premium multi-nutrient fertilizer that delivers potassium, magnesium, and sulfur in a chloride-free, low-salt form. It is especially suited to high-value horticultural crops and situations where balanced nutrition and magnesium or sulfur supplementation are required.
For commercial inquiries, current availability, organic grades, or technical data sheets, please contact us.
