PhD defence by Lærke Wester Larsen

Novel biobased nitrogen fertilizers - Risks of nitrogen losses, agronomic performance & effects on soil quality

The agricultural sector is currently facing the challenges of reducing climate and environmental impacts, like all other sectors. Biobased
fertilizers (BBFs), produced from organic waste and side-streams, could be one of the means to tackle this challenge by recycling otherwise wasted nutrients and substituting mineral fertilizers. Lately, political interest in recycling nutrients, in a circular economy context, has been increasing. Moreover, the commercial BBFs market is growing and many novel BBFs are now being introduced. However, little knowledge exists on the pros and cons of using these novel BBFs. The aim of this PhD research project was therefore to investigate novel BBFs as a substitute for mineral nitrogen (N) fertilizers and i) Evaluate the main N loss risks from the use of BBFs ii) determine the agronomic performance of field crops fertilized with BBFs and iii) evaluate the effect of BBF application on soil quality.

Assessment Committee

Senior Researcher Anne-Kristin Løes, Norwegian Centre for Organic Agriculture, Norway
Professor Jørgen Eriksen, Dept. of Agroecology, Aarhus University, Denmark
Professor Sander Bruun (Chair), PLEN, University of Copenhagen, Denmark

Supervisors

Professor Lars Stoumann Jensen, PLEN, University of Copenhagen, Denmark
Associate Professor Dorette Sophie Müller-Stöver, PLEN, University of Copenhagen, DK

The defence is followed by a reception in meeting room R322/23 on 3rd floor. Everybody is welcome.