Sauvadet Marie auteur aut IRD Lashermes G. auteur aut IRD Alavoine G. auteur aut IRD Recous S. auteur aut IRD Chauvat M. auteur aut IRD Maron P. A. auteur aut IRD Bertrand I. auteur aut IRD text journalArticle eng text/pdf born digital access Increasing the accumulation of organic carbon (C) in soils is a crucial challenge both for soil fertility and for climate change mitigation. Heterotrophic microbial communities are key drivers of C cycling in the soil and are influenced by cultural practices, among other factors. However, whether changes in microbial communities in turn affect their C degradation functions is not well understood. Here, we studied the effects of prior soil management on the microbial taxonomic composition and activity of soils amended with wheat litter. Prior soil management was either conventional (CONV) (i.e., full inversion ploughing) or reduced tillage (RT) during a 5 year period in the same loamy soil in northern France. Soil samples taken from the top 5 cm of field plots were incubated with C-13-labelled litter of either flowering wheat or mature wheat for 29 days at 15 degrees C. We measured the C-CO2 and C-13-CO2, microbial biomass C (MBC) and C-13, and hydrolytic enzyme activities during decomposition. The initial bacterial and fungal community diversity was studied via high-throughput sequencing of ribosomal genes. The results showed that the MBC in the RT soil was initially 1.5-fold greater than that in the CONV soil; contrasting taxonomic compositions were also recorded. The soil biotic legacy impacted the degradation functions when the soils were amended with wheat litter. Compared with that in the CONV soil, the enzymatic efficiency of microorganisms in the RT soil increased by 49% and 61% in the presence of mature and flowering wheat litter, respectively. Enzyme efficiency was positively correlated with microbial litter C use efficiency (CUE) (r = 0.92, P-Value < 0.001) but negatively associated with the priming effect (PE) (r = -0.85, P value < 0.001) across all soils and litter treatments. These findings demonstrated that the RT soil benefited both from an increase in litter C incorporated in the microbial biomass and from a reduction in soil C loss due to the PE, regardless of the quality of the decomposed litter. Our study indicated that agricultural practices such as RT, which enriches the amount of soil organic C (SOC) in the topsoil layer, can lead to positive feedback against C stabilization functions. specialized Soil Decomposition Litter CUE Enzymes Priming effect C-13 FRANCE 068 074 123 64-73 2018 0038-0717 https://www.documentation.ird.fr/hor/fdi:010073627 10.1016/j.soilbio.2018.04.026 0038-0717 [F B010073627] https://www.documentation.ird.fr/hor/fdi:010073627 https://www.documentation.ird.fr/intranet/publi/2018/07/010073627.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2018-09-03 2023-07-11 fdi:010073627 fre