Sulphate of potash is the premium potassium source, and it is bought for one specific reason: it supplies potassium without chloride. If you do not need that, muriate of potash is the cheaper potassium. If you do need it, nothing else will do.
What a tonne delivers
| Per tonne of SOP 0-0-50 | |
|---|---|
| Potassium (K2O) | 500 kg |
| Elemental K | ~415 kg |
| Sulphur (S) | ~170 kg |
| Chloride | Essentially none |
Note the sulphur. SOP is doing two jobs, and on ground short of both potassium and sulphur the sulphur is effectively free against the potassium you were buying anyway.
Who actually needs chloride-free
- Chloride-sensitive crops — grapevines, citrus, avocados, stone fruit, potatoes, berries, tobacco and many vegetables
- Saline or sodic soils, where adding chloride worsens an existing problem
- Irrigated ground with marginal water, where salts accumulate in the root zone season after season
- Quality-driven crops where potassium affects sugar, colour and shelf life and a chloride penalty shows up in the pack-out
Broadacre cereals on non-saline ground generally do not need it — MOP is the sensible buy there. We set the decision out in SOP vs MOP, including why the price gap is real rather than a markup.
Tonnage
| Target K2O | SOP rate | S also applied | 50 ha | 200 ha |
|---|---|---|---|---|
| 50 kg/ha | 100 kg/ha | ~17 kg/ha | 5 t | 20 t |
| 100 kg/ha | 200 kg/ha | ~34 kg/ha | 10 t | 40 t |
| 150 kg/ha | 300 kg/ha | ~51 kg/ha | 15 t | 60 t |
Potassium removal is heavy in fruit, hay and root crops — far heavier than in grain — so horticultural rates run well above broadacre ones.
Granular or soluble
Granular SOP suits spreading and banding. For fertigation and foliar work you want a soluble grade instead — see our water-soluble range and water-soluble or granular. Putting a granular product through an injector is a common and expensive mistake.
Supply
Potassium Sulphate 0-0-50 is supplied in bulk, 1 tonne bulka bags, or 25 kg and 50 kg bags. Minimum order 10–25 MT depending on destination. Horticultural buyers often take bagged product because it is drawn down over months rather than spread in a day — sealed packaging protects it, and SOP takes up moisture like any other soluble salt.
What to send for a quote
- Analysis — the grade you want, or your soil test and we will match it
- Tonnage — and whether it is one delivery or several
- Packing — bulk, 1 t bulka bags, or 25 kg / 50 kg bags
- Delivery address — or destination port for export
- Unloading — what you can unload with on the day
Those five and the quote comes back complete rather than approximate. More on how a quote is built up in what drives your quote.
Tell us the tonnage, the crop and your delivery address. We will confirm whether SOP is genuinely needed or whether MOP would do the same job for less.