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Fertilizer Sampling and Analysis

Fertilizer Analysis Methods 8 CCR 1202-4 Part 6.2

The methods of analysis listed are used by the Colorado Department of Agriculture to analyze commercial fertilizer products. Please contact our office with any questions. For further information on the laboratory, please visit the Inspection & Consumer ServicesBiochemistry Laboratoryweb page.

Fertilizer Confirmatory Method List

Analyte Confirmatory Method Modifications
Total Nitrogen (N) AOAC Official Method 993.13
Nitrogen (Total) in Fertilizers
Combustion Method
None
Soluble Potash (K2O) AOAC Official Method 983.02
Potassium in Fertilizers
Using flame emission spectroscopy in place
of flame photometry (improvements in
technology since method written in 1983)
Available Phosphate (P2O5) AOAC Official Method 960.03
Phosphorus (Available) in Fertilizers
Minor modifications to extraction for safety
purposes
Calcium (Ca) APAC Official Method 965.09
Nutrients (Minor) in Fertilizers
Atomic Absirption
Spectrophotometric Method
Extract - don't boil samples in straight acid
to dryness on hotplate due to safety
concerns
Magnesium (Mg) AOAC Official Method 965.09
Nutrients (Minor) in Fertilizers
Atomic Absorption
Spectrophotometric Method
Extract - don't boil samples in straight acid
to dryness on hotplate due to safety
concerns
Copper (Cu) AOAC Official Method 965.09 (a)
Nutrients (Minor) in Fertilizers
Atomic Absorption
Spectrophotometric Method
Extraction - final dilution in DI water in
place of HCL. Instrument - ICP not AA
(improvement in technology since method
written in 1960)
Iron (Fe) AOAC Official Method 965.09 (a)
Nutrients (Minor) in Fertilizers
Atomic Absorption
Spectrophotometric Method
Extraction - final dilution in DI water in
place of HCL. Instrument - ICP not AA
(improvement in technology since method
written in 1960)
Manganese (Mn) AOAC Official Method 965.09 (a)
Nutrients (Minor) in Fertilizers
Atomic Absorption
Spectrophotometric Method
Extraction - final dilution in DI water in
place of HCL. Instrument - ICP not AA
(improvement in technology since method
written in 1960)
Zinc (Zn) AOAC Official Method 965.09 (a)
Nutrients (Minor) in Fertilizers
Atomic Absorption
Spectrophotometric Method
Extraction - final dilution in DI water in
place of HCL. Instrument - ICP not AA
(improvement in technology since method
written in 1960)
Sulfur (S) AOAC Official Method 980.02
Sulfur in Fertilizers
None

Compost Analysis Methods 8 CCR 1202-4 Part 6.3

The methods of analysis listed are used by the Colorado Department of Agriculture to analyze commercial compost. Please contact our office with any questions. For further information on the laboratory, please visit theBiochemistry Laboratoryweb page.

Compost Confirmatory Method List

Analyte Confirmatory Method TMECC Equivalent
Salmonella sp. Salmonella - FDA BAM Chapter 5 Method Equivalent to 2002 TMECC 07.02-A 1-2
Salmonella Detection Test
Fecal coliform E. coli - FDA BAM Chapter 4 Method Equivalent to 2002 TMECC 07.01-A
Total Coliforms
Carbon LECO Organic Application (Carbon and
Nitrogen in Soil and Sediment)
Equivalent to 2002 TMECC 04.01-A
Combustion with CO2Detection
Nitrogen LECO Organic Application (Carbon and
Nitrogen in Soil and Sediment)
Equivalent to 2002 TMECC 04.02-D
Total N By Oxidation
Ammonia &
Carbon Dioxide
2002 TMECC 05.08-E: Stability and
Maturity Test - SolvitaTM
TMECC 2002 05.08-E Solvita Maturity
Index