GB/T 39228-2020 Active

This standard specifies a method for determining the total amount of extractable organic matter in fresh soil after killing microorganisms with chloroform fumigation, and estimating the biomass of soil microorganisms. This standard only describes the determination of extractable organic carbon content, but the method is also applicable to estimating the nitrogen content of soil microorganisms and the nitrogen content in the indole-3-carbinol reaction of microorganisms. This standard is applicable to the determination of the biomass of soil microorganisms in a wide range of soil pH values, including aerobic and anaerobic (waterlogged, paddy) soils. This standard is also applicable to the determination of the biomass of soil microorganisms in soils containing easily decomposable organic substrates and supersaturated potassium sulfate solutions.
Note: Chloroform fumigation also affects soil animals, but the carbon contribution of these organisms is generally very small (<5%) and can usually be ignored.