Soil methane emissions, primarily from natural wetlands, landfills and rice paddies, are estimated to represent about half of the annual global methane production. Whether a soil is a net source or sink for methane depends on the relative rates of methanogenic and methanotrophic activity. A number of factors including pH, Eh, temperature and moisture content influence methane transforming bacterial populations and soil fluxes. Several techniques are available for measuring methane fluxes. Flux estimation is complicated by spatial and temporal varaibility.
Soil management can impact methane transformations.
For example, landfilling of organic matter can result in significant methane emissions, whereas some cultural practices such as nitrogen fertilization inhibit methane oxidation by agricultural soils. Vallaeys, T. , E. Topp, G. Muyzer, V. Macharet, G. Laguerre, A. Rigaud, and G. Soulas. Evaluation of denaturing gradient gel electophoresis in the detection of 16S rDNA sequence variation in rhizobia and methanotrophs. Alignments of 16S rDNA sequences of known species of rhizobia and methanotrophs were performed in order to determine the genetic variation within a 200 bp product obtained with PCR primers which amplify the 16S rRNA encoding genes from Eubacteria. In the case of the rhizobia, the inability of DGGE analysis to resolve the PCR products from closely related species was in accordance with the low polymorphism observed amongst the sequences in the amplified area.