Explain the significance of potassium as a macrountrient.

Explanation

Potassium (K) :
1. Maintains turgidity and osmotic potential of the cell, opening and closure of stomata, phloem translocation, stimulate activity of enzyme, anion and cation balance by ion - exchange.
2. It is absorbed as `K^+` ions.
Deficiency symptoms : Marginal chlorosis, necrosis, low cambial activity, loss of apical dominance, lodging in cereals and curled leaf margin.