ESTIMATION OF MICROBIAL BIOMASS BY NINHYDRIN-REACTIVE N USING LIQUID CHLOROFORM

Ninhydrin-reactive N (NRN), which is a reliable and sensitive indicato r of soil microbial biomass, was measured in extracts of three Austral ian duplex soils, under different tillage systems, fumigated using eit her vaporized or liquid CHCl3. Although the relationship between the t wo fumigation-extraction methods was influenced by soil type, the use of liquid CHCl3 appears to be a promising technique to allow greater e ase and speed for releasing NRN in microbial biomass analysis.