Nutrient Management Research Database

An adequate K supply is essential for both organic and conventional crop production. Potassium is involved in many plant physiological reactions, including osmoregulation, protein synthesis, enzyme activation, and photosynthate translocation. The K balance on many farms is negative, where more K is removed in harvested crops than is returned again to the soil. An overview of commonly used K fertilizers for organic production is provided.

This paper includes sections on:

• Organic crop production
• Which organic standards to follow
• Using on-farm resources
• Potassium balance
• Potassium release from soil minerals
• Potassium sources for organic production
• Approved and restricted potassium sources including:
  
  • Greensand
  • Langbeinite
  • Manure and compost
  • Potassium Sulfate
  • Rock powders
  • Seaweed
  • Sylvinite
  • Wood ash