Vertical bulk density distribution in C-horizons from marley till as indicator for erosion history in a hummocky post-glacial soil landscape

► Bulk densities in surface-near glacial till C-horizon >1.8gcm−3. ► Calibration of a bulk density model for dense till. ► Prediction of bulk density suggests at least 1m soil loss. For a quantitative understanding of water and element balances of intensively cropped hummocky post-glacial soil landscapes, effects of erosion and colluviation on pedologic structure, and mechanical and hydraulic soil properties should be considered. The C-horizon consisting of glacial till as the parent material can be close to the surface and become part of the plant root zone at exposed locations where topsoil was removed by tillage erosion. Soil bulk density, as one parameter for hydraulic pedotransfer functions, may be characteristic also for the depth location of soil horizons. We propose bulk density as a proxy for the spatially distributed vertical distances between the C-horizon and the soil surface in such landscapes. We analyse the relation between bulk density and depth location for the C-horizon in Luvisol and Regosol soils of various stages of profile reduction by erosion. Within the same diagnostic soil horizon, the bulk density data increased with depth; however, within the C-horizon, the bulk density remained similar or showed a small tendency to decrease with depth. Highest bulk densities of more than 1.8gcm−3 (soil