Fig. 1: Conceptual summary of organo–organic and organo–mineral interactions.
From: Organo–organic and organo–mineral interfaces in soil at the nanometer scale
Shifting conceptual view of the spatial architecture and composition of organo–mineral and organo–organic interactions. a At the scale of aggregate thin-sections, heterogeneous distribution of organic matter (OM) and microbial populations is well-known. b However, previous imaging and spectroscopic characterization of organo–mineral assemblages using a 10–50 μm field of view has shown organized OM layers of different composition. The concept of layered OM accumulation (i.e., the zonal model) has often been linked to nitrogen (N) enrichment at the mineral surface20,21. c–f The images and spectroscopic data presented in this study (conceptualized in c–f) show an order of magnitude smaller spatial scale. c Enrichment of N was detected at an organo–mineral interface in a volcanic soil sample (Fig. 2). d–f Irregular organic structures and the organo–organic interface between them were also detected (in a separate volcanic soil sample) (Figs. 3–5). These observations directly reveal heterogeneous patches that contradict previous assumptions of ordered and unidirectional layering of OM forms, generating new insights into OM composition at mineral–organic and organo–organic interfaces. Note: scale bars are for illustrative purposes only.
