Potassium is the seventh most abundant element in the earth’s crust (approximately 2.3% K) and is found in a number of primary minerals.
Potassium ions are vital for the functioning of all living cells. The transfer of potassium ions across nerve cell membranes is necessary for normal nerve transmission.
Plants require relatively large amounts of Potassium, often as much as nitrogen.
Functions of Potassium (K)
- Potassium provides “Growth Energy” for the plants.Osmotic pressure in cells which helps the plants to use the water.
- Potassium is needed for chlorophyll constructions (chlorophyll is essential photosynthesis).
- Plants need Potassium to make starches, sugars, proteins etc.
Signs of Potassium excess:
- Hard and tight soils
- Nitrate poisoning, milk fever, bloat
- Cow urine burns grass
- Red clover dies out
Potassium deficiency:
- Visual signs – poor grazing recoveries and poor growth, clover grow well in manure patches.
- Necrosis of the tip of the leaves.
- Crop diseases.
Signs of potassium deficiency
Potassium inputs
- Potassium Chloride/Potash KCI 60-62%
- Potassium Sulphate K2SO4 50-53%
- Potassium-Magnesium Sulphate K2SO4+2MgSO4 22%
- Potassium Nitrate KNO3 44-46%
- Manure NA 0.4-1%
- Wood ash NA 5-7%
Potassium as a chemical element
Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives.
