What is potassium?

Submitted by keener.142 on
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what-is-potassium
Answer
Two yellow bananas on a white background.
Photo courtesy of Brett Jordan.

When we think about potassium (K), bananas often come to mind. This soft, silvery metal is much more than that! It is the seventh most common metal in the Earth’s crust, and has been used in fertilizers, detergents, liquid soaps, and more since its discovery by Humphry Davy in 1807.

Potassium is used by all living cells for maintaining fluid and electrolyte balance. Plant cells have a particularly high amount of potassium in them, which they take from the soil. This is why, alongside nitrogen and phosphorus, it is so important to include potassium in fertilizers—otherwise, crops would take it all from the soil and future crops wouldn’t have enough.