PhD fellowship in Climate Change Mitigation in Agriculture

The Climate Change Mitigation and Sustainable Soil Management research group, at the Department of Plant and Environmental Sciences (PLEN), University of Copenhagen, invites applications for a PhD fellowship focused on exploring the effects of biochar application on ammonia (NH3) volatilisation and nitrous oxide (N2O) emissions from agricultural fields following fertilisation. The project is part of the research project “BholdN”, funded by the Agency for Green Land Use and Aquatic Environment (SGAV) under the Ministry of Green Transition. The start date is (expected to be) the 1st of April 2026 or as soon as possible thereafter.

The project

NH3 volatilisation, particularly in connection to fertilisation, causes major environmental problems, including harmful air pollution, eutrophication of aquatic ecosystems, soil acidification, and indirect emissions of N2O, a potent greenhouse gas. It also represents a substantial loss of nitrogen (N) with economic consequences for farmers. Biochar application to agricultural fields is a key element of Denmark’s climate mitigation strategy due to the high carbon storage potential of biochar; however, its effects on NH3 volatilisation are complex, with international studies reporting both reductions and substantial increases of emissions. While biochar-induced increases in soil pH may enhance NH3 volatilisation after fertilisation, the ability of biochar to sorb ammonium (NH4+) to its surface may reduce the deprotonation of NH4+ to NH3. Thus, the potential for increased NH3 volatilisation is a combined result of biochar, soil, and fertiliser properties. Therefore, to make sure that biochar can be used as a safe and effective tool to mitigate climate change in agricultural production without significant environmental trade-offs, we need knowledge of the specific mechanisms controlling the effect of biochar application on NH3 volatilisation.    

The overall objective of the PhD project is to identify key biochar properties that, in combination with different soil and fertiliser types, may enhance NH3 volatilisation from Danish agricultural fields. The project will involve detailed characterisation of biochar properties and a controlled series of laboratory incubations, employing state-of-the-art gas analysers for simultaneous measurements of NH3 and N2O emissions to investigate the synergy between these two vital N gases across relevant biochar, soil, and fertiliser combinations. To further explore the underlying mechanisms, the effects of the heterogeneous matrix formed in soils amended with biochar and fertilisers, characterised by abrupt chemical gradients of pH and N, will be studied using optical 2D chemical sensors (optodes). The spatial patterns of pH and N will be analysed alongside NH3 and N2O emission data, and will be validated in field experiments conducted primarily at the Experimental Farm of the University of Copenhagen, Taastrup. The results will support targeted management strategies and ensure that biochar can be used as a climate mitigation tool without creating environmental hazards.

Who are we looking for?

We are looking for a highly motivated candidate with clear professional ambitions and a strong willingness to actively engage in the workplace. We encourage applicants that holds all or several of the following qualifications to apply for the PhD position:

• A MSc degree within the fields of agronomy, soil science, biology, physical geography, chemistry, environmental science or a related discipline.  
• Solid knowledge of soil biochemistry, with particular emphasis on the N cycle.
• Experience from research within one of the following topics: biochar application to soil, measurements of NH3 volatilisation, greenhouse gas flux measurements, application of 2D optical sensors (optodes) in environmental samples, soil incubation studies, or agricultural field experiments.
• Interest and flair for conducting experimental research in both the laboratory and the field.
• High-level proficiency and interest in academic writing. 
• A basic understanding of statistical methods applied in research.
• Excellent English language skills (written as well as oral).
• Good communicative and interpersonal skills.

Our research group and what do we offer?

The positions will be affiliated with the Climate Change Mitigation and Sustainable Soil Management research group at the Department of Plant and Environmental Sciences at the University of Copenhagen Climate Change Mitigation and Sustainable Soil Management – Institut for Plante- og Miljøvidenskab - Københavns Universitet

The group focuses on soil fertility issues and environmental impacts related to sustainable agriculture with a special focus on nutrient cycling and climate change. Our research aims at a mechanistic understanding of soil nutrient and organic matter dynamics at both the level of micro-scale biogeophysical processes and at ecosystem scales, in the pursuit of increased nutrient use efficiency, improved crop productivity, climate change mitigation, and reduced environmental impacts from agriculture.

We are located in Copenhagen, with the main campus in Frederiksberg and field trial facilities at our experimental farm in Taastrup, 20 km from the main campus. Our research facilities include modern laboratories, growth chambers, greenhouses and experimental fields. We offer creative and stimulating working conditions in a dynamic and international research environment.

Supervision

The Principal supervisor is Professor Sander Bruun, E-mail: sab@plen.ku.dk , Direct Phone: 35333481, and the daily project supervisor (Co-supervisor) is Tenure-Track Assistant Professor Marie Louise Bornø, E-mail: mlb@plen.ku.dk, Direct Phone: 22167085

The PhD programme

Qualifications needed for the regular programme

To be eligible for the regular PhD programme, you must have completed a degree programme, equivalent to a Danish master’s degree (180 ECTS/3 FTE BSc + 120 ECTS/2 FTE MSc) related to the subject area of the project  (see above). For information on the eligibility of completed programmes, see General assessments for specific countries — Uddannelses- og Forskningsstyrelsen and Assessment database — Uddannelses- og Forskningsstyrelsen

Terms of employment in the regular programme

Employment as a PhD fellow is full-time and for a maximum of 3 years.

Employment is conditional upon your successful enrolment as a PhD student at the PhD School at the Faculty of SCIENCE, University of Copenhagen. This requires submission and acceptance of an application for the specific project formulated by the applicant.

The terms of employment and salary are in accordance with the agreement between the Ministry of Finance and the Danish Confederation of Professional Associations on Academics in the State (AC). The position is covered by the Protocol on Job Structure.

Responsibilities and tasks

• Carry through an independent research project under supervision
• Complete PhD courses corresponding to approx. 30 ECTS / ½ FTE
• Participate in active research environments, including a stay at another research institution, preferably abroad
• Teaching and knowledge dissemination activities
• Write scientific papers aimed at high-impact journals
• Write and defend a PhD thesis based on your project

We are looking for the following qualifications:

• Professional qualifications relevant to the PhD project
• Relevant publications
• Relevant work experience
• Other relevant professional activities
• Curious mindset with a strong interest in developing sustainable agricultural systems that minimise greenhouse gas emissions and environmental trade-offs
• Good language skills

Application and Assessment Procedure

Your application, including all attachments, must be in English and submitted electronically by clicking APPLY NOW below.

Please include: 

1. Cover letter / motivated letter of application (max. one page)
2. A short reflection on your research interests, experiences, and how the project objectives can be approached (max. one page)
3. Curriculum vitae including information about your education, experience, language skills and other skills relevant to the position
4. Original diplomas for Bachelor or Master and transcript of records in the original language, including an authorised English translation if issued in a language other than English or Danish. If not completed, a certified/signed copy of a recent transcript of records or a written statement from the institution or supervisor is accepted.
5. Publication list (if relevant)
6. Contact information for two referees (to contact upon request)

Application deadline:

The deadline for applications is 22 February 2026, 23:59 GMT +1.

We reserve the right not to consider material received after the deadline, and not to consider applications that do not live up to the abovementioned requirements.

The further process

After the deadline, a number of applicants will be selected for academic assessment by an unbiased expert assessor. You will be notified whether you will be passed for assessment.

The assessor will assess the qualifications and experience of the shortlisted applicants with respect to the above mentioned research area, techniques, skills and other requirements, and conclude whether each applicant is qualified. The assessed applicants will have the opportunity to comment on their assessment. You can read about the recruitment process at:

https://employment.ku.dk/faculty/recruitment-process/.

Interviews with selected candidates are expected to be held in week 10-12, 2026.

Questions
For specific information about the PhD fellowship, please contact the principal supervisor or co-supervisor.

General information about the PhD study at the Faculty of SCIENCE is available at the PhD School’s website: https://www.science.ku.dk/phd/.

The University of Copenhagen wishes to reflect the surrounding community and invites all, regardless of personal background, to apply for the position.