Journalartikel

Jahr der Veröffentlichung: 2003

Seiten: 651-665

Zeitschrift: Soil Biology and Biochemistry

Bandnummer: 35

Heftnummer: 5

ISSN: 0038-0717

DOI Link: https://doi.org/10.1016/S0038-0717(03)00014-2

Verlag: Elsevier

Abstract: 
The assumption in using the chloroform fumigation technique for microbial biomass determination is that microbes are killed or at least inactivated by the treatment. Problems associated with transformations of the N released on or during fumigation have so far only been associated with the fumigation-incubation method. A laboratory and a field study were carried out to investigate the possible N transformations during biomass determination by the fumigation-extraction method. Labelled NH4NO3 (either the NO3-, NH4+ or both pools were N-15 enriched) was applied to the soil and biomass determinations made at intervals subsequently. The size and enrichment of the ammonium (NH4+), and nitrate (NO3-) pools were determined before and after chloroform fumigation. The N-15 enrichment of the NH4+ Pool after fumigation could only be explained if immobilisation of ammonium occurred at some time during the 24 h fumigation period. The extent of this immobilisation was calculated. In addition, there was evidence that nitrification occurred during the fumigation procedure at the start of the laboratory study and throughout the field study. The laboratory and field study differed mainly in the dynamics related to NO3- uptake and release. There was evidence for uptake of NO3- by the microbial biomass with and without utilization. We conclude that the N-15 enrichment in the microbial biomass cannot be accurately determined when N transformations and release of non-utilized N occurs during fumigation. The possible immobilisation of mineral N during fumigation will affect the magnitude of the factor used to convert measured microbial biomass N to actual microbial biomass N in soil. (C) 2003 Elsevier Science Ltd. All rights reserved.

Harvard-Zitierstil: Müller, C., Stevens, R., Laughlin, R., Ottowa, J. and Jäger, H. (2003) Ammonium immobilisation during chloroform fumigation, Soil Biology and Biochemistry, 35(5), pp. 651-665. https://doi.org/10.1016/S0038-0717(03)00014-2

APA-Zitierstil: Müller, C., Stevens, R., Laughlin, R., Ottowa, J., & Jäger, H. (2003). Ammonium immobilisation during chloroform fumigation. Soil Biology and Biochemistry. 35(5), 651-665. https://doi.org/10.1016/S0038-0717(03)00014-2