Happy to announce the publication of:

Barré, P., Plante, A.F., Cécillon, L. et al. (2016) The energetic and chemical signatures of persistent soil organic matter. Biogeochemistry (2016). doi:10.1007/s10533-016-0246-0. How does soil organic matter change during decomposition? This was the question a team of collaborators led by Dr. Pierre Barré from the French National Centre for Scientific Research wanted to answer using archived soil samples from several long-term bare fallow (LTBF) experiments across Europe. These experiments consist of field plots where plants are prevented from growing. As a result, soils receive no (or minimal) inputs of organic matter. The existing organic matter of the soil at the beginning of the experiment decreases in concentration due to microbial decomposition, becomes increasingly mineral-associated, and presumably changes in composition. That is, the remaining organic matter can be considered increasingly stable or resistant to decomposition. The LTBF experiments from which the archived soils came from range in age, up to 80+ years at the site near the Chateau of Versailles in France. Samples were analyzed using two different thermal analysis procedures (RockEval and TG-DSC-EGA), as well as chemical methods (NEXAFS and FTIR). The results indicate that while there were few consistent patterns in the evolution of soil organic matter chemistry, the pattern in energetics was clear: as bare fallow duration increased, the energy density of the samples declined. We speculate that this change demonstrates a potential energetic barrier to decomposition, which results in long-term stability of residual organic matter.