Title of PhD project: Mitigating climate change: the potential for long-term soil carbon storage in subsoil from deep rooted crops

The increasing emissions of CO₂ and other greenhouse gas emissions are causing global warming leading to massive consequences for ecosystems and human systems. It is therefore critically important to mitigate emissions of greenhouse gases, e.g. through uptake of CO₂ in plants and storage in soils. As the world’s soils comprise the largest terrestrial carbon (C) sink, increasing carbon deposition within the soil while concurrently reducing the decomposition of soil organic matter can function to mitigate climate change.

It is evident that increasing carbon deposition within deeper soil layers (below 1 m) where stored C may be more stable, could function as a particularly effective mitigation process. This is based on expectations that C deposited in deep soil layers can be more permanently stored, as subsoil conditions may be less favorable for its decomposition.

Despite the importance of subsoil C dynamics associated with deep rooted cropping systems in mitigating climate change, there is very little systematic research on carbon deposition and turnover in deep soil layers from deep rooted crops throughout the soil profile, especially in the deep subsoil.

The main aim of the project is to investigate the potential for long-term soil carbon storage in subsoil from deep rooted crops by quantifying the effect of deep rooted crops on soil carbon stocks, and improving our understanding of the factors controlling deposition and decomposition of carbon in deep soil layers.