Rice (Oryza sativa) is usually grown under flooded conditions, leading to anoxic periods in the soil. Rice plants transport oxygen via aerenchyma from the atmosphere to the roots. Driven by O₂ release into the rhizosphere, radial gradients of ferric Fe and co-precipitated organic substances are formed. Our study aimed at elucidating the composition and spatial extension of those gradients. Air-dried soil aggregates from a paddy field were embedded in epoxy resin, cut, and polished to produce cross sections. Reflected-light microscopy was used to identify root channels. With nano-scale secondary ion mass spectrometry (NanoSIMS), we investigated transects from root channels into the soil matrix and detected¹² C⁻,¹⁶ O⁻,¹² C¹⁴ N⁻,²⁸ Si⁻,²⁷ Al¹⁶ O⁻, and⁵⁶ Fe¹⁶ O⁻ to distinguish between embedding resin, organic matter, oxides, and silicates. Image analyses reveal high occurrences of⁵⁶ Fe¹⁶ O⁻ within and in close proximity of oxide-encrusted root cells, followed by a thin layer with high occurrences of²⁷ Al¹⁶ O⁻ and¹² C¹⁴ N⁻ . In two of the three transects,²⁸ Si⁻ only occurs at distances larger than approximately 10 µm from the root surface. Thus, we can distinguish distinct zones: the inner zone is composed of oxide encrusted root cells and their fragments. A thin intermediate zone may occur around some roots and comprises (hydr)oxides and organic matter. This can be distinguished from a silicate-dominated outer zone, which reflects the transition from the rhizosphere to the bulk soil.