The uptake of K is frequently as high as or even higher than the uptake of nitrogen.
Potassium is an essential element for all living organisms.
Although the overall effects of K on photosynthesis, carbohydrate and protein synthesis and on the water economy of the plant have been confirmed in numerous experiments, the actual functions of this element in the physiology of the plant and in yield formation have for long been obscure. Only recently, with the more detailed investigation of the manifold processes of plant metabolism, have some of the questions as to how potassium functions in the plant been answered. A salient feature of K is the high rate at which it is taken up by the plant. Though, in contrast to many other indispensable elements, K is not a constituent of organic compounds, it is omnipresent in the plant and very mobile. This mobility and the participation of K in the activation of important enzyme reactions are two fundamental characteristics of this element.