A healthy diet of Special K gives crops strength to help survive a
drought.
Potassium, also known as potash or K, helps plants draw water from the
soil, create sugar and produce protein from nitrogen.
“Potassium is one of the keys to plant-drought survival,” says Adrian
Johnston, an agronomist with the Potash and Phosphate Institute.
Added Rich Szwydky of the Saskatchewan Soil Conservation Association:
“(Plants without enough potassium) dehydrate more easily and they fail
to use their other natural defenses well. Next to nitrogen, they use
Read Also
Agriculture ministers agree to AgriStability changes
federal government proposed several months ago to increase the compensation rate from 80 to 90 per cent and double the maximum payment from $3 million to $6 million
more potassium than anything else.”
The mineral has many uses.
Stomates are the pores in plant skin that open and close to exchange
water vapour, carbon dioxide and oxygen. They are crucial to preventing
dehydration, and must open and close fully and quickly to prevent
excessive water loss while still allowing plants to cool themselves and
move gasses back and forth.
Stomates need an adequate supply of potassium because it attracts water
to neighbouring cells, causing them to swell and open.
When water is in short supply, such as in dry, windy weather, potassium
is pumped out of these cells and the pores close tightly, reducing
water loss and wilting.
Stomates that don’t have enough potassium become sluggish and fail to
close fully, leaving the plant exposed to the air for longer than
necessary. Water lost at this stage cannot be used to grow, produce
seed or operate the stomates.
Potassium regulates the pressure in special tissue cells that move
plant leaves to prevent overheating or drying, or face the sun for
higher rates of photosynthesis and growth.
A potassium shortage will prevent plants from converting nitrogen into
protein, which in turn prevents cereals and oilseeds from taking
advantage of low moisture conditions to store high protein levels in
seeds.
Potassium increases hydraulic pressure in the cells of regular stem
tissue, which makes stems stronger and more resistant to lodging.
Potassium helps plant roots absorb water by increasing osmotic pressure
and making tissue more absorbent.
Potassium is necessary for photosynthesis, the process that produces
sugar that plants need to grow and make grain. Potassium ions act as
magnets, drawing in other needed elements.
Plants that can move chemical compounds and fluids quickly are better
able to fight disease because they can react to infection more rapidly
and thoroughly.
Low potassium levels can cause already drought-stressed plants to be
more vulnerable to disease or insects.
