Biochar alters the soil microbiome and soil function: results of next generation amplicon sequencing across Europe

Jenkins JR, Viger M, Arnold EC, Harris ZM, Ventura M, Miglietta F, Girardin C, Edwards RJ, Rumpel C, Fornasier F, Zavalloni C, Tonon G, Alberti G & Taylor G (2016): Biochar alters the soil microbiome and soil function: results of next generation amplicon sequencing across Europe. GCB Bioenergy Adv. Access DOI: 10.1111/gcbb.12371

Abstract

Wide scale application of biochar to soil has been suggested as a mechanism to offset increases in CO2 emissions through the long-term sequestration of a carbon rich and inert substance to the soil, but the implications of this for soil diversity and function remain to be determined. Biochar is capable of inducing changes in soil bacterial communities, but the exact impacts of its application are poorly understood. Using three European sites (UK SRC, short rotation coppice, French grassland (FR) and Italian SRF, short rotation forestry (IT)) treated with identical biochar applications; we undertook 16S and ITS amplicon DNA sequencing. In addition, we carried out assessments of community change over time and N and P mobilisation in the UK.

Significant changes in bacterial and community structure occurred due to treatment, although the nature of the changes varied by site. STAMP differential abundance analysis showed enrichment of Gemmatimonadete and Acidobacteria in UK biochar plots one year after application, whilst control plots exhibited enriched Gemmataceae, Isosphaeraceae and Koribacteraceae. Increased mobility of ammonium and phosphates were also detected after one year, coupled with a shift from acid to alkaline phophomonoesterase activity, which may suggest an ecological and functional shift towards a more copiotrophic ecology. Italy also exhibited enrichments, in both the Proteobacteria (driven by an increase in the order Rhizobiales) and the Gemmatimonadetes. No significant change in the abundance of individual taxa were noted in FR, although a small significant change in unweighted UNIFRAC occurred, indicating variation in the identities of taxa present due to treatment. Fungal β diversity was affected by treatment in IT and FR, but was unaffected in UK samples. The effects of time and site were greater than that of biochar application in UK samples. Overall, this report gives a tantalising view of the soil microbiome at several sites across Europe, and suggests that although application of biochar has significant effects on microbial communities, these may be small compared with the highly variable soil microbiome that is found in different soils and changes with time.

iOES Poster: Using metagenomics to assess soil microbial diversity under future climate scenarios

Joseph Jenkins, Prof. Gail Taylor, Dr. Rich Edwards.

1st International Environmental Omics Synthesis (iEOS) Conference, Cardiff, UK (Sept 11-13, 2013). Poster CE-3.

Abstract:

Soil microbes are responsible for the function of biogeochemical cycles, which are essential to maintain soil quality. Anthropogenic climate change is resulting in variation of the soil habitat, through alteration of a multitude of soil variables. In particular, prevalence of drought and use of geoengineering methods to sequester carbon (such as biochar) are expected to increase.

To test the implications of drought and biochar amendment in soil habitats, soil samples were collected from two long term experimental sites, and shotgun metagenomic sequencing undertaken to determine changes in soil microbial diversity. Furthermore, analysis of the method itself will be undertaken to determine potential issues with the technique, and to improve the methodology for future studies.

Future work will attempt to compare results of shotgun and amplicon metagenomic methods, and sequencing of additional biochar treated samples from a range of European sites undertaken. This will provide a means to compare changes in microbial diversity after biochar incorporation under a variety of field conditions, providing insight into its likely effects for soil microbial ecology.

1st International Environmental Omics Synthesis (iEOS) Conference

The lab has a couple of posters at the 1st International Environmental Omics Synthesis (iEOS) Conference conference in Cardiff this week (Sept 11-13), so come and say hello to Joe and/or Alex if you are in Cardiff.

Poster EcO-15:

UNDERSTANDING PLANT ADAPTATION TO THE CHANGING ENVIRONMENT USING NEXT GENERATION RNA TRANSCRIPTOME SEQUENCING

Alex Watson-Lazowski, Yunan Lin, Jennifer DeWoody, Richard Edwards and Gail Taylor. Centre for Biological Sciences, University of Southampton.

Plant adaptation to elevated atmospheric carbon dioxide (CO2) is of great interest, as the concentration of this gas in the atmosphere has risen by more than 30% to 388 μmol mol-1 since the industrial revolution. On average there has been a rise of 3 ppm per year. Plant fossil samples suggest that atmospheric CO2 may be acting as a selective agent driving evolution, but limited evidence is available to support this idea for plants subjected to future predicted concentrations. Studying evolutionary responses to this aspect of environmental change is difficult, but here we use a CO2 spring site where plants have been exposed for multiple generations to concentrations of CO2 predicted for 2050. From this, detailed phenotyping data was collected, including data for stomatal patterning. Considerable evidence exists to show that stomatal numbers have declined across geological time and that this is linked to CO2 concentration, but few CO2-sensitive stomatal patterning genes have ever been identified. When grown under elevated CO2 concentrations P. lanceolata (the narrow leaf plantain), seeds collected from the spring site showed a counter-intuitive change in stomatal index and density. Here, in this non- model plant we have investigated the gene expression changes underlying this stomatal patterning response to elevated CO2.

RNA-Seq allows for in depth analysis of plant species with no previous information required, enabling rapid evaluation of any of novel plant acclimations and adaptions. Using this approach we have identified a set of novel genes for stomatal patterning in high CO2 and confirmed previously observed acclimation responses.

RNA-Seq refers to the use of high-throughput deep-sequencing technologies to sequence cDNA in order to get information about the transcriptome of a given biological sample.

Poster CE-3:

USING METAGENOMICS TO ASSESS SOIL MICROBIAL DIVERSITY UNDER FUTURE CLIMATE SCENARIOS

Joseph Jenkins, Prof. Gail Taylor, Dr. Rich Edwards. University of Southampton, ExpeER, EuroChar.

Soil microbes are responsible for the function of biogeochemical cycles, which are essential to maintain soil quality. Anthropogenic climate change is resulting in variation of the soil habitat, through alteration of a multitude of soil variables. In particular, prevalence of drought and use of geoengineering methods to sequester carbon (such as biochar) are expected to increase.

To test the implications of drought and biochar amendment in soil habitats, soil samples were collected from two long term experimental sites, and shotgun metagenomic sequencing undertaken to determine changes in soil microbial diversity. Furthermore, analysis of the method itself will be undertaken to determine potential issues with the technique, and to improve the methodology for future studies.

Future work will attempt to compare results of shotgun and amplicon metagenomic methods, and sequencing of additional biochar treated samples from a range of European sites undertaken. This will provide a means to compare changes in microbial diversity after biochar incorporation under a variety of field conditions, providing insight into its likely effects for soil microbial ecology.