Short-term responses of soil respiration induced with biochar and lime in acid soil

Biochar amendments have been widely proposed as a conventional and efficient strategy to promote soil organic carbon (SOC) sequestration via negative priming. Unfortunately the extent and biological mechanisms responsible for biochar-induced 193 negative priming are still not fully understood. Despite traditional explanations focused on the environmental filtering mechanisms of biochar amendments on microbial biomass and community composition underlying the priming effect on SOC dynamics whether and how a biochar-induced competitive network structure with keystone taxa determines SOC mineralization in natural ecosystems has been minimally explored. Here we paid particular attention to the relationships between the diversity and network structure of soil bacterial and fungal communities and SOC mineralization. A 3-year field experiment was conducted comprising five treatments: no fertilization conventional fertilization and conventional fertilization with three rates of biochar amendments. Biochar amendments considerably increased soil moisture and pH and subsequently shaped the composition and co-occurrence networks of soil bacterial and fungal communities. Importantly network analysis coupled with stable isotope probing incubations consistently determined that biochar amendments reshaped the competitive modular structure with putative keystone taxa in the bacterial and fungal networks. Structural equation modeling suggested that the biochar-induced competitive modular structure with keystone taxa promoted bacterial and fungal diversity and consequently reduced carbohydrate catabolism and soil metabolic quotient. Our study revealed that biochar-induced competition with keystone taxa stimulated the bacterial and fungal diversity and consequently decreased SOC mineralization. The comprehensive understanding of the unexplored biological mechanisms underlying the biochar-induced negative priming may provide crucial implications for enabling SOC sequestration. Biochar amendments considerably increased

Bibliographic Details

Main Authors:	Durdevic, Boris, Jug, Irena, Knicker, Heike, Brozovic, Bojana, Vukadinovic, Vesna, Jug, Danijel
Format:	póster de congreso biblioteca
Published:	International Union of Soil Sciences 2020-05-13T16:56:41Z
Online Access:	http://hdl.handle.net/10261/211312
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