Biochar and denitrification in soils: when, how much and why does biochar reduce N2O emissions?

By M. Cayuela, M. Sánchez-Monedero, A. Roig, K. Hanley, A. Enders, Johannes Lehmann. Scientific Reports, 2013

690 citations recorded by the source corpus.

Agricultural soils represent the main source of anthropogenic N2O emissions. Recently, interactions of black carbon with the nitrogen cycle have been recognized and the use of biochar is being investigated as a means to reduce N2O emissions. However, the mechanisms of reduction remain unclear. Here we demonstrate the significant impact of biochar on denitrification, with a consistent decrease in N2O emissions by 10–90% in 14 different agricultural soils. Using the 15N gas-flux method we observed a consistent reduction of the N2O/(N2 + N2O) ratio, which demonstrates that biochar facilitates the last step of denitrification. Biochar acid buffer capacity was identified as an important aspect for mitigation that was not primarily caused by a pH shift in soil. We propose the function of biochar as an “electron shuttle” that facilitates the transfer of electrons to soil denitrifying microorganisms, which together with its liming effect would promote the reduction of N2O to N2.

Subfields: Ecology, Evolution, Behavior and Systematics, Environmental Chemistry, Soil Science

View Paper: https://www.semanticscholar.org/paper/5f37f9ee8f43adb437a436754f69674955acf513

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In Ecology, Evolution, Behavior and Systematics

In Environmental Chemistry

In Soil Science

Citations in the corpus

The way forward in biochar research: targeting trade‐offs between the potential wins (2015, background): “Biochar has also been suggested to function as an ‘electron shuttle’ that facilitates the transfer of electrons to denitrifying microorganisms (Cayuela et al., 2013a, 2013b).”
Redox properties of plant biomass-derived black carbon (biochar). (2014, background): “Electron shuttling towards denitrifying 71 microorganisms in soils was invoked to rationalize lower N2O emissions from char 72 amended soils compared to non-amended control treatments.(33-35) 73 Electron transfer catalysis by intermediate and high temperature chars may involve 74 two types of redox-”
Biochar alters the soil microbiome and soil function: results of next‐generation amplicon sequencing across Europe (2017, background): “, 2013), increased transfer of electrons, resulting in augmentation of biological processes (Cayuela et al., 2013), shifts in microbial N cycling (Harter et al.”
Linking N2O emissions from biochar-amended soil to the structure and function of the N-cycling microbial community (2013, background): “, 2013), whereas other studies described that the addition of biochar to soils does affect soil N2O emissions (Yanai et al., 2007; Singh et al., 2010b; Taghizadeh-Toosi et al., 2011; Felber et al., 2012; Cayuela et al., 2013).”