DIN EN ISO 14240-2:2011-09

This part of ISO 14240 specifies a method for the estimation of microbial biomass of soils by measurement of total extractable organic biomass material mainly from freshly killed microorganisms. The method is also applicable to the estimation of microbial nitrogen and microbial ninhydrin-reactive nitrogen in soil, but this part of ISO 14240 describes only the measurement of extractable organic carbon. The fumigation-extraction method is applicable to aerobic and anaerobic (water-logged, paddy) soils over the whole range of soil pH. Biomass can be also measured in soils containing actively decomposing substrates and soils supersaturated with potassium sulfate solution. Soil consists of both living and nonliving components which exist in a complex and heterogeneous environment. Soil microflora is responsible for the degradation of organic matter, stability of aggregates and most nutrient cycling which occurs in soils. The purpose of determining the microbial biomass of soils is to allow assessment of the continued maintenance of soil fertility, the potential ability to degrade added organic materials, and the effects of added materials on the natural microbial population. The ISO 14240 series consists of the following parts, under the general title "Soil quality - Determination of soil microbial biomass": - Part 1: Substrate- induced respiration method - Part 2: Fumigation-extraction method Expert assistance and specialized laboratories will be required to perform the procedure described in this standard. The text of ISO 14240-2:1997 has been prepared by Technical Committee ISO/TC 190 "Soil quality" of the International Organization of standardization (ISO) and has been adopted as EN ISO 14240-2:2011 by Technical Committee CEN/TC 345 "Characterization of soils", the secretariat of which is held by NEN. The text of ISO 14240-2:1997 has been approved by CEN as EN ISO 14240-2:2011 without any alterations. The Committee responsible for this standard is NA 119-01-02-04 UA "Biologische Verfahren" ("Biological Methods") at DIN.