12 June 2018 - Tillage practices change the ability of microorganisms to degrade organic matter

12 June 2018 - Tillage practices change the ability of microorganisms to degrade organic matter

Stabilizing carbon in soil as organic matter is crucial at the local scale for soil fertility, and at the global scale for climate change mitigation. The carbon stocks in the soil depend on the "inputs" made in particular by organic inputs (plant litters, organic amendments, etc.) transformed into stable organic matter in the soil under microorganisms activities. They also depend on the "outputs", especially the ability of microorganisms to degrade the ‘old’ carbon stock of the soil.

In the SOFIA project (SOil Functional diversity as an Indicator of sustainable management of Agroecosystems), we studied the impact of two tillage practices - conventional and reduced tillage - on microbial communities and their degradation functions. We sampled soils at the Long Term Ecological Research (LTER) experiment of Estrée-Mons (France), measured microbial diversity at Agroecology Laboratory and GenoSol platform (Dijon, France), measured microbial growth, and respiration, and extracellular enzymatic activities at FARE. For the same carbon input in the form of a plant litter, the soil microbial communities under reduced tillage respired less and incorporating more carbon, making it possible to better stabilize this carbon in the soil compared to the soil microbial communities under tillage. In parallel, less stabilized carbon was destocked by the process of "priming effect" by microbial communities of soil under reduced tillage. Our results indicate that reduced tillage practices can have a positive feedback on soil carbon stabilization functions.

Read: Sauvadet M, Lashermes G, Alavoine G, Recous S, Chauvat M, Maron PA, Bertrand I. High carbon use efficiency and low priming effect promote soil C stabilization under reduced tillage. Soil Biology and Biochemistry, 2018, 64–73, https://doi.org/10.1016/j.soilbio.2018.04.026

Contact: Dr Gwenaëlle Lashermes, gwenaelle.lashermes@inra.fr

Modification date : 06 June 2023 | Publication date : 05 June 2018 | Redactor : G. Lashermes / G. Paës