Soil Testing and Plant Diagnostic Services

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Soil test procedures

  • Soil pHs (1:1 solution:soil suspension). Solution is 0.01M CaCl2
  • Lime requirement (neutralizable acidity) uses the Woodruff buffer solution
  • Organic matter percentage by loss on ignition
  • Extractable phosphorus (Bray-1 P)
  • Exchangeable potassium (ammonium acetate extraction)
  • Exchangeable calcium (ammonium acetate extraction)
  • Exchangeable magnesium (ammonium acetate extraction)
  • Cation exchange capacity (estimated from exchangeable potassium, calcium, magnesium and neutralizable acidity)
  • Extractable zinc (DPTA extraction)
  • Extractable sulfur (calcium phosphate in acetic acid extraction)
  • Extractable iron, manganese and copper (DPTA extraction)
  • Exchangeable sodium (ammonium acetate extraction)
  • Hot water extractable boron (0.1 percent CaCl2. H20)
  • Nitrate-nitrogen and ammonium-nitrogen (2 M KCl extraction)
  • Soluble salts (electrical conductivity in a 1:1 soil:water saturation extraction)
  • Particle size analysis (hydrometer method)

Soil test procedures for MU laboratories (PDF)
Recommended Chemical Soil Test Procedures for the North Central Region

Updated 9/14/11