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Methods


METHODS USED AT WESTERN LABORATORIES FOR SOILS
Parameter Units Method-Number Methods
pH Unit S-2.20 1:1 Soil:Water Ratio

pH SMP Buffer

      

Soluble Salts

 mmhos/cm 1:2 Soil:Water Ratio

Organic Matter

 % S-9.10 LOI

Lime

 % Fizz Effervescense 2N HCL

Nitrates – NO3

 ppm = mg/kg S-3.10 Cadnium Reduction/KCL Extraction

Ammonium – NH4

 ppm = mg/kg S-3.50 KCL Extraction/Exchangeable

Phosphorus – Basic Soils

 ppm = mg/kg S-4.10 Bicarbonate

Phosphorus – Acid Soils

 ppm = mg/kg   Bray

Potassium

 ppm = mg/kg S-5.10 NH4 OAc Extractable

Calcium

 ppm = mg/kg S-5.10 NH4 OAc Extractable

Magnesium

 ppm = mg/kg S-5.10 NH4 OAc Extractable

Sodium

 ppm = mg/kg S-5.10 NH4 OAc Extractable

Zinc

 ppm = mg/kg S-6.10 DTPA Extractable

Iron

 ppm = mg/kg S-6.10 DTPA Extractable

Manganese

 ppm = mg/kg S-6.10 DTPA Extractable

Copper

 ppm = mg/kg S-6.10 DTPA Extractable

Sulfate

 ppm = mg/kg S-5.10 NH4 OAc Extractable

Boron

 ppm = mg/kg S-6.10 DTPA Extractable/Sorbitol

Texture

 Unit   By feel

Cation Exchange Capacity

 meq = cmol/kg NH4 OAc Measured

Total Phosphorus

 % P-4.10 Wet Ashing

SAR = % Na of CEC

   S-1.60 NH4 OAc


METHODS USED AT WESTERN LABORATORIES FOR PLANTS
Parameter Units Method-Number Methods

Nitrates – NO3

 ppm = mg/kg S-3.10 Cadnium Reduction/NH4 OAC Extractable

Ammonium – NH4

 ppm = mg/kg S-3.50 Cadnium Reduction/NH4 OAC Extractable

Phosphorus – Basic Soils

 ppm = mg/kg S-4.10 Bicarbonate

Phosphorus – Acid Soils

 ppm = mg/kg   Bray

Potassium

 ppm = mg/kg S-5.10 Wet Ash

Calcium

 ppm = mg/kg S-5.10 Wet Ash

Magnesium

 ppm = mg/kg S-5.10 Wet Ash

Sodium

 ppm = mg/kg S-5.10 Wet Ash

Zinc

 ppm = mg/kg S-6.10 Wet Ash

Iron

 ppm = mg/kg S-6.10 Wet Ash

Manganese

 ppm = mg/kg S-6.10 Wet Ash

Copper

 ppm = mg/kg S-6.10 Wet Ash

Sulfate

 ppm = mg/kg S-5.10 Wet Ash

Boron

 ppm = mg/kg S-6.10 Wet Ash