Healthy soils are the result of a dynamic interplay of biological, chemical and physical processes that are significantly influenced by management. In this session, the complex relations between soil life and soil organic matter formation will be explored. It will discuss how different management practices can promote or endanger soil biodiversity, as well as the respective effects on soil organic matter formation. One focus will be on the soil carbon formation theory and the latest findings in soil biology, which broaden our understanding of stabilisation and destabilisation of soil organic carbon and soil fertility. In addition, threats to soil health from erosion, as well as unsustainable fertilization and pesticides and their effects on soil ecosystems and the microbiome will be discussed.