Unexpected stimulation of soil methane uptake as emergent property of agricultural soils following bio‐based residue application |
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Authors: | Adrian Ho Andreas Reim Sang Yoon Kim Marion Meima‐Franke Aad Termorshuizen Wietse de Boer Wim H van der Putten Paul L E Bodelier |
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Institution: | 1. Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO‐KNAW), PB Wageningen, The Netherlands;2. Max Planck Institute for Terrestrial Microbiology, Marburg, Germany;3. SoilCares Research, PD Wageningen, The Netherlands;4. Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO‐KNAW), PB Wageningen, The Netherlands;5. Laboratory of 6. Nematology, Wageningen University and Research Centre (WUR), ES Wageningen, The Netherlands |
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Abstract: | Intensification of agriculture to meet the global food, feed, and bioenergy demand entail increasing re‐investment of carbon compounds (residues) into agro‐systems to prevent decline of soil quality and fertility. However, agricultural intensification decreases soil methane uptake, reducing, and even causing the loss of the methane sink function. In contrast to wetland agricultural soils (rice paddies), the methanotrophic potential in well‐aerated agricultural soils have received little attention, presumably due to the anticipated low or negligible methane uptake capacity in these soils. Consequently, a detailed study verifying or refuting this assumption is still lacking. Exemplifying a typical agricultural practice, we determined the impact of bio‐based residue application on soil methane flux, and determined the methanotrophic potential, including a qualitative (diagnostic microarray) and quantitative (group‐specific qPCR assays) analysis of the methanotrophic community after residue amendments over 2 months. Unexpectedly, after amendments with specific residues, we detected a significant transient stimulation of methane uptake confirmed by both the methane flux measurements and methane oxidation assay. This stimulation was apparently a result of induced cell‐specific activity, rather than growth of the methanotroph population. Although transient, the heightened methane uptake offsets up to 16% of total gaseous CO2 emitted during the incubation. The methanotrophic community, predominantly comprised of Methylosinus may facilitate methane oxidation in the agricultural soils. While agricultural soils are generally regarded as a net methane source or a relatively weak methane sink, our results show that methane oxidation rate can be stimulated, leading to higher soil methane uptake. Hence, even if agriculture exerts an adverse impact on soil methane uptake, implementing carefully designed management strategies (e.g. repeated application of specific residues) may compensate for the loss of the methane sink function following land‐use change. |
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Keywords: | atmospheric methane oxidation bio‐based residues greenhouse gas methane methanotrophs
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