Potassium (K)
Role in plants
Potassium regulates water balance, enzyme activation, sugar transport, stomatal function, stress tolerance, and fruit quality.
Deficiency symptoms
- Marginal leaf scorch or necrosis
- Weak stems
- Reduced drought and cold tolerance
- Poor fruit size and quality
Toxicity symptoms
- Suppression of magnesium and calcium uptake
- Leaf scorch
- Salinity stress symptoms
Natural sources
- Feldspar and mica minerals
- Clay exchange sites
- Decomposing plant residues
Fertiliser sources
- Potassium nitrate
- Potassium sulphate
- Potassium chloride (limited use in sensitive crops)
Plant uptake forms