This is based on the quantification of C input by roots and rhizodeposition and the relative microbial stabilization in deep soil layers across functionally distinct deep-rooted perennial plant species. Collectively, her PhD study is the first of its kind to show that deep-rooted perennial crops can allocate considerable quantities of carbon to deep soil layers, and specifically the N₂ fixing legume displays a greater potential for microbial stabilization of carbon in deep soil layers.

The new research findings promote the understanding of plant C input and microbial transformations in the deep subsoil, and for the first time shows that the theoretical target of offsetting CO₂ emissions via carbon storage in deep subsoils is promising with the use of a leguminous deep-rooted perennial crop.

The PhD study was completed at Department of Agroecology, Faculty of Technical Sciences, Aarhus University.

This summary was prepared by the PhD student.

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

Contact information: Leanne Elizabeth Ellen Koley Peixoto, e-mail: leanne.peixoto@agro.au.dk, tel.: +45 52 82 79 76

Members of the assessment committee:

Professor Francesca Cotrufo, Soil and Crop Sciences, Colorado State University, USA

Professor Pascal Boeckx, Isotope Bioscience Laboratory, Ghent University, Belgium

Senior researcher Chris Kjeldsen (chairman), Department of Agroecology, Aarhus University, Denmark

Main supervisor:
Professor Jørgen Eivind Olesen, Department of Agroecology, Aarhus University, Denmark

Co-supervisors

Senior researcher Jim Rasmussen, Department of Agroecology, Aarhus University, Denmark

Associate Professor Lars Elsgaard, Department of Agroecology, Aarhus University, Denmark

Language: The PhD dissertation will be defended in English

The defence is public.

The PhD thesis is available for reading at the Graduate School of Technical Sciences/GSTS, Katrinebjergvej 89F, building 5132, 8200 Aarhus N.