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Competency Area 4: Nutrient Sources, Analyses, Application Methods

PO 29. Describe the physical form and analysis of each of the following calcium and/or magnesium sources.

  1. Calcitic lime
  2. Dolomitic lime
  3. Gypsum
  4. Potassium magnesium sulfate
  5. Lime
  6. Hydrated or slaked lime
  1. Calcitic lime: calcium carbonate, CaCO3
    • Fertilizer grade: 32% Ca
    • Physical form: solid
  2. Dolomitic lime: calcium magnesium carbonate, CaMg(CO3)2
    • Fertilizer grade: 22% Ca
    • Physical form: solid
  3. Gypsum: calcium sulfate, CaSO4
    • Fertilizer grade: 18-23% Ca, 15-19% S
    • Physical form: solid
  4. Potassium magnesium sulfate: K2SO4•MgSO4
    • Fertilizer grade: 22% K2O, 11% Mg, 22% S
    • Physical form: solid, water-soluble
    • Good source of Mg and S
    • Often referred to as Sul-Po-Mag or K-Mag
  5. Lime: also burned lime, quicklime, calcium oxide: CaO
    • Physical form: solid
  6. Hydrated or slaked lime: calcium hydroxide, Ca(OH)2
    • Fertilizer grade: 46% Ca
    • Physical form: solid