Effects of preconditioning the rhizosphere of different plant species on biotic methane oxidation kinetics

Abstract

The rhizosphere is known as the most active biogeochemical layer of the soil. Therefore, it could be a beneficial environment for biotic methane oxidation. The aim of this study was to document - by means of batch incubation tests - the kinetics of CH4 oxidation in rhizosphere soils that were previously exposed to methane. Soils from three pre-exposure to CH4 zones were sampled: the never-before pre-exposed (NEX), the moderately pre-exposed (MEX) and the very pre-exposed (VEX). For each pre-exposure zone, the rhizosphere of several plant species was collected, pre-incubated, placed in glass vials and submitted to CH4 concentrations varying from 0.5% to 10%. The time to the beginning of CH4 consumption and the CH4 oxidation rate were recorded. The results showed that the fastest CH4 consumption occurred for the very pre-exposed rhizosphere. Specifically, a statistically significant difference in CH4 oxidation half-life was found between the rhizosphere of the VEX vegetated with a mixture of different plants and the NEX vegetated with ryegrass. This difference was attributed to the combined effect of the preconditioning level and plant species as well as to the organic matter content. Regardless of the preconditioning level, the oxidation rate values obtained in this study were comparable to those reported in the reviewed literature for mature compost.

Characteristics and metabolic patterns of soil methanogenic archaea communities in the high‐latitude natural forested wetlands of China

“…Shifts in plant communities can have a large influence on the activity and community composition of methanogens via inducing changes in environmental conditions or in the substrates available for root exudation from photosynthate (Merila et al, 2006;Wu et al, 2012). Plant roots, by producing secondary macropores, can strengthen soil aeration, change the redox potential in root environments, and ultimately influence methane emissions (Ndanga et al, 2016). In addition, temperature is considered a key factor affecting seasonal and annual variations in CH 4 fluxes in wetlands (Bloom et al, 2012;Chen et al, 2013;.…”

Design of Microbial Methane Oxidation Systems for Landfills

“…areas of high CH 4 fluxes or uncontrolled emissions, at the surface of the landfill cover. Ensuring a more even distribution of the CH 4 loading greatly improves emissions abatement, with CH 4 oxidation rates attaining nearly 100% of the applied loading (Huber-Humer, 2004a;Bogner et al, 2007;Roncato and Cabral, 2012;Ndanga et al, 2015;Ndanga et al, 2016).…”

Characteristics and Metabolic Patterns of Soil Methanogenic Archaea Communities in the High Latitude Natural Wetlands of China

“…Shifts in vegetation communities can have a large in uence on the activity and community composition of methanogens via changes in environmental conditions or in the substrates available for root exudation from photosynthate [27,28]. Plant roots, by producing secondary macropores, can also strengthen soil aeration, change the redox potential in root environments, and ultimately in uence methane emissions [29]. In addition, temperature is considered a key factor affecting seasonal and annual variations in CH 4 uxes in wetlands [14,30,31].…”