Potassium sulphate (SOP, sulphate of potash, K2SO4) is a chloride-free potassium fertilizer that supplies both potassium (K) and sulphur (S) without adding chloride to the soil. Its low-chloride profile makes it the preferred potassium source for chloride-sensitive and high-value crops. Siman has supplied potassium sulphate and other potash fertilizers to buyers on six continents since 1994, exporting granular and crystalline (soluble) grades in bulk and bagged quantities to more than 90 countries.
Potassium sulfate is a high-quality potassium fertilizer rich in sulfur and potassium with low chlorine content. It is primarily applied to crops like grapes, citrus, flowers, tobacco, and those that thrive in low-oxygen environments. Additionally, it is favored for the cultivation of sensitive crops, such as those grown in greenhouses or through hydroponic methods, making it a premium choice for fertilization.
What is potassium sulphate?
Potassium sulphate is a white crystalline salt with the formula K2SO4, also known as sulphate of potash or SOP and expressed as 0-0-50 in NPK terms. Fertilizer-grade SOP typically contains around 50–52% water-soluble potassium (as K2O) and 17–18% sulphur, with a very low chloride content. Because it adds no chloride and has a low salt index, it is chosen wherever potassium chloride (MOP) would risk chloride injury, leaf burn, or salt build-up in the root zone.
Applications and uses
Chloride-sensitive and high-value crops
SOP is the standard potassium source for crops sensitive to chloride and to salinity – grapes and wine, citrus, tobacco, potatoes, tomatoes and other vegetables, berries, avocados, coffee, tea, and ornamentals and flowers. The added sulphur supports protein and oil formation, chlorophyll, and the flavour, aroma and shelf-life quality that these markets are paid for.
Fertigation, greenhouse and hydroponics
The soluble crystalline grade dissolves cleanly for drip irrigation, fertigation, and foliar spraying, and is widely used in greenhouse and hydroponic systems where a low-chloride, low-salt nutrient solution is essential.
Broad-acre and industrial uses
Granular SOP is applied to open-field crops that reward high quality and to chloride-sensitive soils. Beyond agriculture, potassium sulphate is also used in some industrial applications such as specialty glass and as a raw material in chemical processing.
Grades, packaging and storage
Potassium sulphate is commonly supplied in two forms: a granular grade for direct field and blend application, and a crystalline/soluble grade for fertigation, foliar use and hydroponics. Siman can offer granular and crystal SOP in 25 kg bags, 50 kg bags, big bags (FIBC) and bulk. Store in a dry, covered area, keep bags sealed to prevent caking from moisture, and keep away from strong acids. Exact grades, packaging and specifications available for your order:
Siman Ltd can offer it granular and crystal in various packings – 25 kg bags, 50 kg bags, big bags.
Please contact us for more information.
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Potassium sulphate supplier and export
Siman has traded fertilizers and industrial chemicals since 1994 and ships to more than 90 countries across six continents, from Bulgaria to Europe, Africa, the Americas, Asia and Australia. We source from well-checked suppliers, can arrange independent third-party quality and quantity inspection, and guarantee the timing of delivery, quality and packing. We work on CFR, CIF, DDU, DDP and CIP terms, with orders usually from one full container or 100 MT (smaller LCL quantities possible on some products). You get on-spec chloride-free potassium, correct export documentation, and a responsive team. Request a quote or check availability – call +359 888 804 562, message us on WhatsApp or Viber, or send an inquiry through the contact form.
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Frequently asked questions
What is potassium sulphate (SOP) used for?
It is a chloride-free potassium and sulphur fertilizer used mainly on chloride-sensitive, high-value crops – grapes, citrus, tobacco, potatoes, vegetables, berries and ornamentals, and in fertigation, greenhouse and hydroponic systems.
Why choose potassium sulphate instead of potassium chloride (MOP)?
SOP adds no chloride and has a low salt index, so it avoids the chloride injury and salinity build-up that MOP can cause on sensitive crops and soils. It also supplies sulphur, which MOP does not.
Which markets do you export potassium sulphate to?
We export to more than 90 countries across six continents and handle export documentation and CFR/CIF/DDU/DDP/CIP delivery. Tell us your market and we will confirm availability.