Scharpenseel, H.-W., Becker-Heidmann, P., Freytag, J. (1991): Accounting for soil dynamic induced 13C shifts in evaluating landscape development. – In: International Atomic Energy Agency (Hg.): Stable isotopes in plant nutrition, soil fertility, and environmental studies, S. 275–279. IAEA, Vienna
The best identification which we can give to soil organic matter today is obtained by analysis of C and N content, C/N ratio and extinction ratio (Q 4/6), 13C nuclear magnetic resonance (four peaks for carbonic acids, aromates, carbohydrates and aliphatics), gas chromatography-mass spectrometry (for major chemical constituents), isotope ratio analysis, analysis of δ13C and δ18O (for the origin of the organic matter from C3, C4 and CAM photosynthesis and for palaeoclimate) and infrared spectrometry (for functional groups, if not determined by classical methods).
While organic matter turnover is usually measured by means of radioactive, 14C labelled compounds or C residence time and exchange rates are tested on the basis of low level D14C concentrations, C dynamics in the course of organic matter transport, laterally downslope in catenas or vertically with changing soil profile morphology, are assessed preferably on the basis of stable isotope measurement, especially δ13C measurement. The latter approach has a wide potential also for identification of facets of landscape development. Basic pools are the atmosphere with ca. 720 Gt C and a δ13C of -7‰, the biosphere with ca. 560 Gt C and δ13C, depending on the mode of photosynthesis, from -25‰ to -10‰, and the pedosphere with ca. 2000 Gt C, the δ13C of carbonate free organic matter being similar to that of the biosphere, but with slight deviations due to the C dynamics in the soils (e.g. due to evaporation and percolation). These deviations of a few per mil compared with the PDB standard  can be very helpful for identification of soil dynamic processes.
Bertram  recognized from δ13C measurements a recent increase of C in the pedosphere and biosphere amounting to ca. 60 Gt C.
Freytag  described the mechanism of calcareous crust development (ad ascensum, ad descensum and catenary lateral) on the basis of δ13C and δ18O measurements.