Johannes Jensen

Ph.d.-studerende

Johannes Jensen
Se relationer på Aarhus Universitet

Profil

Project title: Identification of soil organic carbon thresholds to sustain soil functions in agroecosystems.

Project description: Decline in soil organic carbon is considered as a main threat to sustained soil quality at global, European and national scale. The decline may accelerate due to the increased pressure on maximizing the biomass output from arable land to meet the future challenges of producing more food. Consequently it is crucial to develop new sustainable ways of managing agricultural soils. Seen in this context, there is an urgent need to identify a lower critical threshold for soil organic carbon for sustained soil functioning for soils with different textures. The turnover of organic carbon per se also plays a vital role for soil functioning. Therefore, it is of great importance to study to what extent stimulation of organic carbon turnover in the soil via increased input of labile organic carbon can offset low soil organic carbon levels, and if the soil organic carbon level is affecting the turnover of added organic matter.

The research aims at determining critical levels of inherent soil content of carbon and improving our knowledge on added organic carbon for the purpose of restoring or sustaining soil structure. This is done by focusing on the ratio between mineral fines (<20 µm) and soil organic carbon. We expect that this ratio identifies a functional threshold for soil physical behaviour as well as decomposability by microbes of labile organic matter. 

ID: 32792310