Analysis of the stable isotopes abundance of light elements involved in bio-geochemical processes in soil-plant-air continuum. Applications include isotope ratio analysis at natural abundance levels and enriched levels for D/H, 13C/12C, 15N/14N, 18O/16O and 34S/32S. Analysis in bulk soil material, biological tissue, chars, concentrated precipitates; trace gas analysis (CH4, CO2, N2O)