Chloroform fumigation

Incubated under sterile (chloroform fumigation) and nonsterile conditions (organic acid application according to the composition of root exudates). 

P. C. Brookes, L. Landman, and D. S. Jenkin.son, Chloroform fumigation and the release of soil nitrogen a rapid extraction method to measure microbial biomass nitrogen in soil. Soil Biol. Biochem. 17331 (1985). 

L. Zelles, A. Palojarvi, E. Kandeler, M. VonLut/.ow, K. Winter, Q. Y. Bai. Changes in. soil mierobial properties and phospholipid fatty acid fractions after chloroform fumigation. Soil Biol. Biochem. 29 1325 (1997). 

Historically, measurement of the microbial biomass has been a tedious, time-consuming occupation involving staining and direct counting or use of culture media and enumeration of individual microbial communities. However, in the last 20 years, a suite of methods have been developed for more rapid assessment of the microbial biomass. These include the substrate-induced respiration method (Anderson and Domsch 1978), the chloroform fumigation-incubation method (Jenkinson and... 

Microbial biomass carbon Chloroform fumigation incubation Indicates soil microbial population various methodologies controls nutrient cycling and biological transformation necessary for soil aggregation dependent upon organic inputs Rice et al. (1996)... 

Microbial biomass P Chloroform fumigation extraction Indicate biologically active fraction of soil phosphorous control P cycle dependent upon organic amendments Brookes et al. (1982)... 

Chloroform fumigation also increases the amount of total N extractable with 0.5 M K2S04. Brookes et al. (1985) showed that this extra N also comes from the microbial biomass and proposed that biomass N could be estimated from the relationship, Biomass N = 2.22 EN, where EN is analogous to Ec. 

Brookes, P. C., Landman, A., Pruden, G., and Jenkinson, D. S. (1985). Chloroform fumigation and the release of soil nitrogen A rapid direct extraction method to measure microbial biomass nitrogen in soil. Soil Biol. Biochem. 17, 837-842. Brookes, P. C., Powlson, D. S., and Jenkinson, D. S. (1982). Measurement of microbial biomass phosphorus in soil. Soil Biol. Biochem. 14, 319-321. 

Voroney, R.P., and E.A Paul, (1984), Determination of K and in situ for Calibration of the Chloroform Fumigation Incubation Method. Soil Biol. Biochem. 16 9-14. 

Dickens, H. E., and Anderson, J. M. (1999). Manipulation of soil microbial community structure in bog and forest soils using chloroform fumigation. Soil Biol. Biochem. 31, 2049-2058. 

Oberson, A., Friesen, D.K., Morel, C. and Tiessen, H. (1 997) Determination of phosphorus released by chloroform fumigation from microbial biomass in high P sorbing tropical soils. Soil Biology and Biochemistry 29, 1 579-1 583. 

Ross, D.J., Sparling, C.P. and West, A.W. (1 987) Influence of Fusarium oxysporum age on proportions of C, N and P mineralized after chloroform fumigation in soil. Australian Journal of Soil Research 25, 563-566. 

Zelles, L., Palojarvi, A., Kandeler, E., von LQtzow, M., Winter, K. and Bai, Q.Y. (1997) Changes in soil microbial properties and phospholipid fatty acid fractions after chloroform fumigation. Soil Biology and Biochemistry 29, 1325-1336. 

Depending on the soil type, the efficiency factor (refers to chloroform fumigation extraction efficiency) may vary from 0.3 to 0.4. Caution should be exercised in using these efficiency factors. In recently accreted soils with high labile organic matter content and in soils containing fine roots, use of efficiency factors may overestimate the MBP. 

Moderately labile organic phosphorus (MLOP) The residual soil after chloroform fumigation is extracted with 1 M HCl, followed by centrifugation at 6,000 rpm. Supernatant liquid is filtered through 0.45 pm membrane filter. Filtered solutions are analyzed for total phosphorus and inorganic phosphorus. The difference between these two fractions is called MLOP. 

The introduction of the chloroform fumigation technique represents a significant advance in the assessment of the soil biomass. In conjunction with other methods, the technique has shown that the biomass is large, but greatly restricted in its activity because of the low levels of available nutrients. The fungi form a major component of the biomass. The biomass comprises only a small proportion of the total soil organic matter, but it is a comparatively labile fraction. 

ANDERSON J.P.E. and DOMSCH K.H. 1978. fungi in chloroform fumigated soils. 

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