The Swiss Soil Monitoring Network NABO was implemented in the 1980s to observe soil quality and its evolution on the long-term. About 100 monitoring sites are resampled every 5 years for chemical analyses. In addition, management data are obtained for agricultural sites allowing for a dual approach combining results from monitoring with mass balances (indirect monitoring). The assessed chemical parameters include pH, organic carbon, nutrients and trace elements (heavy metals), and organic pollutants (POPs, pesticides). Selected sites are visited yearly to analyse soil biological parameters. Furthermore, penetration resistance is measured for agricultural sites to assess soil compaction.