Retention and release of nutrients from polyhalite to soil

Timothy D. Lewis*, Paul D. Hallett, Graeme Paton, Luke Harrold

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Recent discoveries of polyhalite (K2SO4.MgSO4.2CaSO(4).2H(2)O) in the UK provide an alternative to conventional fertilizer sources. This work investigated the interaction of polyhalite, commercially known as POLY4, with soil using leaching columns. Different physical forms of polyhalite (powder, crushed rock and granules) were compared to potassium chloride (KCl) for the movement of potassium, calcium, magnesium and sulphur (as sulphate) through the soil profile using 19.7 L of water, equivalent to 4,500 mm rainfall. The nutrients from polyhalite were found to be available at 30 cm depth, with calcium showing signs of interacting with the soil clay particles to release cationic nutrients. Polyhalite granules showed the greatest release of sulphate, magnesium and calcium as a proportion of the additional nutrient with 127%, 71% and 102%, respectively leached. For potassium, all forms of polyhalite had greater release than KCl (powder = 58%; granules = 86%; crushed rock = 57% and KCl 16%). Nutrients from polyhalite and those mobilized from soil interactions are present in soil solution indicating availability for plant growth.

Original languageEnglish
Pages (from-to)117-122
Number of pages6
JournalSoil Use and Management
Issue number1
Early online date17 Oct 2019
Publication statusPublished - Jan 2020


  • agriculture
  • fertilizer
  • nutrient movement
  • polyhalite
  • potassium
  • soil


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