Is Potassium Sulfate Soluble And How To Use It In The Soil

Is Potassium Sulfate Soluble And How To Use It In The Soil

The one important question most farmers have not found adequate answers to, “is Potassium Sulfate soluble and how to use it in the soil”? Here we discuss this fertilizer so that farmers can have a better understanding.

Potassium sulfate is an excellent source of Potassium for plants. It provides the much-needed Potassium minerals in a stable Ph neutral form. With some brands certified as organic, you can choose from a variety.

Potassium fertilizers come in different types.  If you don’t understand their differences, it is difficult to distinguish them.  Potassium sulfate is the best choice for both organic and conventional gardeners.

Is Potassium Sulfate Soluble?

Not all Potassium Sulfate fertilizers are alike. There are synthetic potassium sulfates and organic certified. Potassium sulfate that comes from natural mining sources is the one that is certified organic. This Potassium has not undergone any kind of further processing.

Is Potassium Sulfate Soluble?

Unfortunately, some unprocessed raw materials are not soluble. They carry unwanted minerals that do not help the plant. Only a few sources of organic potassium sulfate are soluble. Knowledgeable sales staff should be able to tell you the source of their fertilizers. And whether their product is soluble or not.

Potassium sulfate does not dissolve easily.  Generally, only a 1/3 is soluble.  Most of it does not dissolve especially through irrigation.

It is also important to know the grade of the Potassium fertilizer you are buying. Large particles of Potassium Sulfate are barely soluble and not a good choice. The best grade is the fines with small particles about 0.015mm and below. Fine grades dissolve easily and are better to use in foliar sprays or irrigation.

Check this organic fertilizer from Down to Earth that provides a source of potassium, magnesium, and sulfur for your plants.

Essential Functions of Potassium Sulfate in Plants

Potassium sulfate helps to complete a majority of essential functions in plants. Some of these functions include:

  • Activating enzyme reactions
  • Synthesizing proteins
  • Forming starch and sugars
  • Regulating water flow in leaves and cells

In most cases, Potassium in the soil is too low to support healthy plant growth. And for this reason, you can choose to add Potassium Sulfate to your plants.

How To Use Potassium Sulfate In Soil

Potassium deficiency in plants usually show signs on the leaves as they turn yellow. To provide fast-acting potassium to such plants, it is best to use foliar feeding sprays. The foliar spray made from clean water and soluble Potassium stops the problem from spreading.

Highly concentrated Potassium fertilizer can burn the leaves. Be sure to use mild concentrations of foliar sprays. You would rather spray mild concentration many times rather than use the concentrated one.

The application rate depends on the quality of your soil.  Apply 2 pounds of Potassium sulfate per 100 square feet or 2 tablespoons per gallon of water.

How To Use Potassium Sulfate In Soil


Just like the human body, plants also experience a lack of necessary nutrients. A fertilizer that replenishes the plant’s nutrients is the same as supplements that humans need. Likewise, as you take your supplement today, be sure to check if your plants need some!