For green manure, the chemical signatures of low alkyl ratio and large C/N, as well as large alkyl ratio and low C/N were co-localized (Figure 3). At the end of the incubation, we were able to map the decrease in the alkyl ratio of green manure particles and increase in their C/N signatures (Figures 2 and 3). Chemical maps for straw confirmed the co-localization of low alkyl ratio and large C/N, as well as the opposite. We generally detected a lower contribution of very small straw particles and, as observed for green manure, the variability in both alkyl ratio and C/N was similar between very small and within large particles (Figure 4).