Potassium versus Calcium

Plants need a good supply of  nutrition and two elements that assist with the absorption are calcium and potassium. To get the best absorption the ratio between them is important. However, depending on the conditions, these two elements compete with each other.

The Different Properties

A significant different between the two stems from the ion charge. Calcium ions have two positive charges and when reacting with other elements will form molecules that are insoluble. However, the salts that potassium ions, which have one positive charge, are soluble. As a result a plant will absorb and transport them in different ways.

Because potassium forms soluble substances a plant can easily transport large concentrations.

Calcium is transported in the space between cells and depends on water transpiration for its movement. It can only move from the roots to the stems, whereas potassium can move up and down the plant as required.

Competition Between the Elements

Because they are both positively charged they are effectively competing for negatively charged elements and they both require a connection with these to be transported.

Ideal Ratios

The ideal ratios vary significantly between different plants and the table below gives an indication of this