Basisfosfor en kalium: foarmen, lykwicht en pleatsing

Ierdappelfieding searje · Diel 03 fan 24 · Alle ûnderdielen yn oarder

Phosphorus moves little in soil, and the potato root system is relatively limited. Its availability in the young root zone is therefore often more important than the formal amount per hectare. The UK Potash Development Association (PDA) explains that phosphate recommendations for potatoes are significantly higher than crop offtake, while potassium demand is especially high during active growth and bulking.

The PDA's March 2026 overview gives a reference point for the balance: tubers contain around 5.8 kg K₂O per tonne. So 40 t/ha means roughly 232 kg K₂O/ha removed, and 70 t/ha about 406 kg. This is an offtake calculation, not a fertilizer rate: part of the K comes from the soil, and the maximum K accumulated by the crop exceeds what the tubers remove. A rate cannot be obtained by simply multiplying yield by a coefficient.

The source of potassium also matters. In Ireland, Teagasc stresses that for some processing purposes sulphate forms can maintain dry matter better than chloride; but excess potassium of any form can also reduce dry matter. The chloride form is not banned in principle: the choice depends on timing, soil and contract requirements for the tubers.

Geografy en praktyske tapassing

British and Irish recommendations work as a calculation method for a humid temperate climate; low-K fields in Eastern Europe need their own diagnosis. On the irrigated sands of Idaho, special attention goes to the K accumulation phase and monitoring.

Agronomyske begelieding hjir is algemiene praktyk; sprek tariven en timing ôf mei jo agronoom.

Partnermateriaal: Uralchem produkten - betingste seleksje

NPKS 8:20:30:3

For base or banded application, Uralchem's granular NPKS 8:20:30:3 can be considered: according to the catalogue it contains 8% N (ammonium form), 20% P₂O₅, 30% K₂O and 3% S. The rate is calculated from soil analysis and the balance of all nutrient sources; a brand name does not replace a field calculation.

Produktfoto's: Uralchem.

Gjin oanbefelling foar tariven - rieplachtsje jo agronoom.

boarnen

• Potash Development Association, Nutrient Considerations for Potatoes (March 2026).
• Teagasc, Potato agronomy and nutrition.
• University of Idaho Extension, Nutrient management: Potatoes.
• Uralchem, NPKS 8:20:30:3 product specification.