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

Wide‐scale application of biochar to soil has been suggested as a mechanism to offset increases inCO2emissions 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 ItalianSRF, short rotation forestry (IT)] treated with identical biochar applications, we undertook 16S andITSampliconDNAsequencing. In addition, we carried out assessments of community change over time and N and P mobilization in theUK. Significant changes in bacterial and community structure occurred due to treatment, although the nature of the changes varied by site.STAMPdifferential abundance analysis showed enrichment ofGemmatimonadeteandAcidobacteriainUKbiochar plots 1 year after application, whilst control plots exhibited enrichedGemmataceae, IsosphaeraceaeandKoribacteraceae. Increased mobility of ammonium and phosphates was also detected after 1 year, coupled with a shift from acid to alkaline phosphomonoesterase activity, which may suggest an ecological and functional shift towards a more copiotrophic ecology. Italy also exhibited enrichments, in both theProteobacteria(driven by an increase in the orderRhizobiales) and theGemmatimonadetes. No significant change in the abundance of individual taxa was noted inFR, although a small significant change in unweightedUNIFRACoccurred, indicating variation in the identities of taxa present due to treatment. Fungalβdiversity was affected by treatment inITandFR, but was unaffected inUKsamples. The effects of time and site were greater than that of biochar application inUKsamples. Overall, this report gives a tantalizing 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.