Patterns of soil organic carbon and nitrogen in relation to soil movement under different land uses in mountain fields (South Central Pyrenees)

► 137Cs as effective tracer of sources and sinks of SOC and SON. ► Soil organic carbon and nitrogen pattern distributions associated with soil particles. ► Paralleled increases of SOC and SON downslope in mountain contoured fields. ► Depositional sites at bottom slopes as effective sinks of SOC and SON. ► SOC and SON contents affected by topography, land use and land abandonment.