Modification of fumigation extraction method for measuring soil microbial biomass carbon

Both K_(2)Cr_(2)O_(7)-H_(2)SO_(4) additional heating method and the traditional K_(2)Cr_(2)O_(7)-HgO-H_(2)SO_(4)-H_(3)PO_(4) method were used in measuring the carbon in soil K_(2)SO_(4) extract. It was found that the former method is much more safe, simple and fast than the later one. The results obtained by the K_(2)Cr_(2)O_(7)-H_(2)SO_(4) additional heating method are also more accurate and precise than those by the traditional K_(2)Cr_(2)O_(7)-HgO-H_(2)SO_(4)-H_(3)PO_(3) one. Thus, the K_(2)Cr_(2)O_(7)-H_(2)SO_(4) additional heating method can be used in the routine analysis measurement of soil microbial biomass carbon.