Mechanisms of biochar decreasing methane emission from Chinese paddy soils

Abstract Paddy fields are one of the largest anthropogenic sources of global CH 4 emission. A decrease in paddy CH 4 emission can contribute significantly towards the control of global warming. Recent studies have demonstrated that the application of biochar in paddy soils has such a capability, but its underlying mechanism has yet to be elucidated. In this investigation, we studied CH 4 emission, methanogenic archaeal, as well as methanotrophic proteobacterial communities, from microcosms derived from two paddy soils, Inceptisol and Ultisol. Both soils were amended with biochar at different pyrolysis temperatures (300 °C, 400 °C and 500 °C) at field condition. The soil CH 4 flux was monitored across whole rice season in 2010; the functional guilds communities were analyzed by PCR–DGGE and real-time quantitative PCR (qPCR). It is found that paddy CH 4 emissions significantly decreased under biochar amendments, which, interestingly, didn't result from the inhibition of methanogenic archaeal growth. qPCR further revealed that biochar amendments (1) increased methanotrophic proteobacterial abundances significantly, and (2) decreased the ratios of methanogenic to methanotrophic abundances greatly. These results shed insight on the underlying mechanism of how biochar decreases paddy CH 4 emission. This knowledge can be applied to develop a more effective greenhouse gas mitigation process for paddy fields.

[1]  J. V. van Elsas,et al.  The ecology of transfer of mobile genetic elements. , 2002, FEMS microbiology ecology.

[2]  H. Fritze,et al.  Charcoal as a habitat for microbes and its effect on the microbial community of the underlying humus , 2000 .

[3]  J. Lehmann,et al.  Bacterial Community Composition in Brazilian Anthrosols and Adjacent Soils Characterized Using Culturing and Molecular Identification , 2009, Microbial Ecology.

[4]  Markus Antonietti,et al.  Effect of biochar amendment on soil carbon balance and soil microbial activity , 2009 .

[5]  Lianqing Li,et al.  Effect of biochar amendment on yield and methane and nitrous oxide emissions from a rice paddy from Tai Lake plain, China. , 2010 .

[6]  M. Kimura,et al.  Community structure of methanogenic archaea in paddy field soil under double cropping (rice-wheat) , 2006 .

[7]  M. Saier,et al.  Climate Change, 2007 , 2007 .

[8]  Ke Ma,et al.  Regulation of microbial methane production and oxidation by intermittent drainage in rice field soil. , 2011, FEMS microbiology ecology.

[9]  J. Lehmann,et al.  Bio-char soil management on highly weathered soils in the humid tropics , 2006 .

[10]  M. Nei,et al.  MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0. , 2007, Molecular biology and evolution.

[11]  J. Skjemstad,et al.  Formation, transformation and transport of black carbon (charcoal) in terrestrial and aquatic ecosystems. , 2006, The Science of the total environment.

[12]  J. Lehmann.  Bio-energy in the black , 2007 .

[13]  A. Cowie,et al.  Biochar and Emissions of Non-CO2 Greenhouse Gases from Soil , 2012 .

[14]  Gang Liu,et al.  CO2 mitigation potential in farmland of China by altering current organic matter amendment pattern , 2010 .

[15]  D. Crowley,et al.  Bacterial diversity of terra preta and pristine forest soil from the Western Amazon , 2007 .

[16]  J. Ladha,et al.  Enhancing Soil Quality through Residue Management in a Rice-Wheat System in Fukuoka, Japan , 2005 .

[17]  Ying-xu Chen,et al.  Reducing CH4 and CO2 emissions from waterlogged paddy soil with biochar , 2011 .

[18]  M. Kimura,et al.  Dynamics of methanogenic archaeal communities based on rRNA analysis and their relation to methanogenic activity in Japanese paddy field soils , 2007 .

[19]  P. Frenzel,et al.  Activity and Distribution of Methane-Oxidizing Bacteria in Flooded Rice Soil Microcosms and in Rice Plants (Oryza sativa) , 1997, Applied and environmental microbiology.

[20]  P. Frenzel,et al.  A methane-driven microbial food web in a wetland rice soil. , 2007, Environmental microbiology.

[21]  Johannes Lehmann,et al.  A handful of carbon , 2007, Nature.

[22]  J. Lehmann,et al.  Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal – a review , 2002, Biology and Fertility of Soils.

[23]  P. Crutzen,et al.  Estimates of gross and net fluxes of carbon between the biosphere and the atmosphere from biomass burning , 1980 .

[24]  T. Lueders,et al.  Stable-Isotope Probing of Microorganisms Thriving at Thermodynamic Limits: Syntrophic Propionate Oxidation in Flooded Soil , 2004, Applied and Environmental Microbiology.

[25]  K. Yagi,et al.  Wheat straw management affects CH4 and N2O emissions from rice fields , 2009 .