Visually healthy crop, but low production? Check potassium levels
There are many cases where the potato looks healthy above ground, but at the end of the growing season it yields small, amorphous or soft tubers. The
cause, in most cases, is not pathogens, but a deficiency in potassium –
a vital element for potato cultivation.
Potassium is involved in starch synthesis, regulation of water balance and
bark strengthening. Its shortage directly affects the quantity and quality of
production.
Potassium requirements For every ton of tubers produced, the
plant absorbs an average of 5.8 kg of K₂O. Therefore, a yield of 4-5 tonnes per hectare
requires 20-30 kg of pure potassium. In many cases, basal fertilization does not meet
the entire requirement, resulting in limited tuber size, reduced
starch concentration and reduced maintenance.
Time of application
Basic potassium fertilization is preferably done before planting (late autumn or
early spring). If potassium chloride is used, it is critical to allow a sufficient
period of time for the chlorine to be removed and phytotoxicity to be avoided.
In contrast, potassium sulphate can be applied closer to sowing.
The second key moment is the samara phase (30-40 days after planting),
when tuber formation begins.If potassium chloride is used, it is critical to allow sufficient
time for the chlorine to be removed and avoid phytotoxicity.
In contrast, potassium sulphate can be applied closer to sowing.
The second key moment is the samaroma phase (30-40 days after planting),
when tuber formation begins. There, a complementary application of potassium
also offers maximum efficiency.
Form of fertiliser
Potassium chloride (KCl) is cheaper, but can degrade the quality of
tubers, especially in soils with drainage problems or in sensitive varieties.
Potassium sulphate (K₂SO₄) is preferred , as it increases the starch content and
reduces the occurrence of physiological abnormalities (e.g. black spot).Fertilizer form
Potassium chloride (KCl) is more economical, but can reduce the quality
of tubers, especially in soils with drainage problems or in sensitive varieties.
Potassium sulphate (K₂SO₄) is preferred as it increases the starch content and
reduces the occurrence of physiological abnormalities (e.g. black spot).
Soil analysis and foliar diagnostics
The ability to retain and supply potassium depends on the soil type.
Clay soils retain more potassium; sandy soils lose it easily due to
leaching.Soil analysis and foliar diagnostics
The ability to retain and supply potassium depends on the soil type.
Clay soils retain more potassium; sandy soils lose it easily due to
leaching. pH, organic matter and overall nutritional status affect
intake.
Soil analysis prior to fertilization is essential, while foliar diagnostics , i.e.
potassium measurement on stems during growth, reveals whether feeding is
adequate.pH, organic matter and overall nutrient status affect
uptake.
Soil analysis before fertilization is essential, while foliar diagnostics , i.e.
potassium measurement on stems during growth, reveals whether the supply is
adequate. In the intercostals, levels of 8-10% K are considered satisfactory.
Planning, precision and geotechnical guidance
The potato responds positively when its real needs are met. Potassium
is fundamental for productivity, quality and postharvest behaviour.
The two critical applications – before planting and during initial tuber formation –
also determine the final result.Potassium
is fundamental for productivity, quality and postharvest behaviour.
The two critical applications, before planting and during initial tuber formation,
also determine the final outcome.
The selection of the right type of fertilizer, the timing and the use of the
available diagnostic tools should always be done with the advice of an agronomist.
Correct planning means higher yields and lower costs
of corrective interventions.
See all available fertilizer types for potatoes and learn more
about the crop in the ZIKO potato growing guide from ZIKO.Choosing the right fertilizer type, timing and using the
available diagnostic tools should always be done with the advice of an agronomist.
Proper planning means higher yields and lower costs
of corrective interventions.
See all available fertilizer types for potatoes and learn more
about the crop in the ZIKO Potato Growing Guide from ZIKO.
