Sulfate of Potash (SOP): Specification & Supply
Product: Potassium Sulfate (SOP)
Also known as: Sulfate of Potash (SOP)
Chemical formula: K₂SO₄
Standard grade: 0-0-50 + 17–18% S
Sulfate of Potash (SOP) Overview
Potassium sulfate, commonly called sulfate of potash (SOP), is described as a chloride-free potassium fertilizer that supplies potassium (K) and sulfur (S). The page presents it as the preferred potassium source for chloride-sensitive crops and where soil or irrigation water already contains high chloride levels.
SOP is produced either from natural mineral sources or through chemical processes (such as the reaction of potassium chloride with sulfuric acid). The final product is available in granular or crystalline form. Standard grade on this page is 0-0-50 + 17–18% S.
Sulfate of Potash (SOP) Technical Specifications
Technical Specifications
| Parameter | Unit | Standard / Typical Value |
|---|---|---|
| Potassium Oxide (K₂O) | % | 50 min (typically 50–52) |
| Sulfur (S) | % | 17–18 min |
| Chloride (Cl) | % | ≤ 0.5–2.5 max (low-Cl grades ≤ 0.5) |
| Moisture | % | 0.5 max (up to 1.5 in some grades) |
| Water Insoluble | % | ≤ 0.5–2.5 (depending on grade) |
| pH (solution) | — | Neutral to slightly alkaline |
| Appearance | — | White to off-white granules or crystals |
| Particle Size (granular) | — | Predominantly 1–4 mm or 2–4 mm |
| Bulk Density (approx.) | kg/m³ | 1,300–1,600 |
Key Benefits
- Chloride-free
- — Ideal for chloride-sensitive crops and saline soils.
- Dual nutrient supply
- — Delivers both potassium and sulfur in one product.
- Improves crop quality
- — Enhances fruit size, colour, sugar content, flavour, oil content, and shelf life.
- Supports plant resilience
- — Strengthens drought tolerance, disease resistance, and overall plant vigour.
- Lower risk of soil salinity
- — Safer option than MOP in areas with high chloride or sensitive crops.
- Sulfur contribution
- — Essential for protein synthesis, oil production, and enzyme activity (particularly valuable for oilseeds and legumes).
- Note:
- SOP is generally more expensive than MOP (Potassium Chloride) due to its higher purity and chloride-free nature. It is therefore most cost-effective for high-value or chloride-sensitive crops.
Recommended Applications
- Highly Recommended (Chloride-sensitive & high-value crops):
- Fruits: Grapes, berries, citrus, bananas, apples, pears
- Vegetables: Potatoes, tomatoes, carrots, lettuce, onions
- Cash crops: Tobacco, coffee, tea, almonds, nuts
- Oilseeds & legumes: Canola, sunflower, soybeans (where sulfur is also needed)
- Greenhouse, hydroponic, and fertigation systems
- Also suitable for:
- Sulfur-deficient soils
- Areas with high chloride in soil or irrigation water
- Organic farming systems (certain certified grades available)
Packing and Shipping
- 50 kg polypropylene bags
- 1,000 kg jumbo bags (FIBC)
- Bulk (loose) delivery for large-scale operations
Storage and Handling
- Store in a cool, dry, well-ventilated warehouse protected from moisture.
- Keep bags sealed and stacked on pallets to prevent caking.
- Avoid prolonged exposure to high humidity.
- Use standard personal protective equipment during handling.
Why Ametheus
- Specification values, packing and storage notes are those already published on this page.
- No origin country was named; none was added.
Related pages: Muriate of Potash (MOP) | Fertilizers.
FAQ
What standard grade is stated?
0-0-50 + 17–18% S.
Why does the page present SOP as distinct from MOP?
It is described as chloride-free, and as the preferred potassium source for chloride-sensitive crops and high-chloride soils or irrigation water.
What packing is listed?
50 kg polypropylene bags; 1,000 kg jumbo bags (FIBC); and bulk (loose) delivery for large-scale operations.
Inquiry
For current availability, grade, quantity and delivery window, please include:
- Grade or form, and any specification limits you require
- Quantity and packing
- Destination and preferred delivery window
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