PhD in Horticultural Science

Original title: PhD student in Horticultural Science

Department of Biosystems and Technology

PhD Project: Valorization and Risk Assessment of Anaerobic Digestates for Sustainable Horticultural Production

Third-cycle subject area: Horticultural Science

Description of the doctoral project

The transition to circular food and energy systems requires safe, high-quality products that can return nutrients and organic matter to horticultural production. Anaerobic digestate from biogas production is a promising resource containing plant nutrients and organic fibre originating from, for example, manure, food and household waste, slaughterhouse by-products, park and garden residues, and biomass from intermediate crops or roadside vegetation. The digestate can be separated into a nutrient-rich liquid fraction and a fibre fraction. While the liquid fraction has potential for use in nutrient solutions, the fibre fraction is particularly relevant as a constituent of growing media and a potential partial replacement for peat and other fibre materials. Developing safe, functional and locally available alternatives to peat is an important challenge for sustainable horticultural production. A key barrier is the possible presence of pyralid herbicide residues. These herbicides can accumulate in crop material, persist during anaerobic digestion and cause growth disturbances in sensitive horticultural crops at very low concentrations. The project will investigate the occurrence and fate of pyralids in selected feedstocks and digestate fractions, with particular focus on the fibre fraction and its use in growing media.

The doctoral project will combine greenhouse and growth-chamber bioassays with laboratory studies and chemical characterisation. It will assess effects on plant growth and nutrient uptake, examine the distribution, degradation and immobilisation of herbicide residues, and generate knowledge to support risk assessment and the safe valorisation of digestate-derived growing-media products. The project is an important part in the ongoing transition for more circular productions systems where plant nutrients and fiber is recycled from waste to production. The project is a part of the Biogas Solutions Research Center, which means that there will be collaboration with other PhD students both at SLU and at Linköping University. Communication of results, both orally and in writing to both academic and industrial stakeholders are also important parts of the project. As a PhD-student, you will also take PhD courses and be a part of the daily work at the department.

To meet the general entry requirements you must have been awarded a second-cycle (Master’s) qualification, satisfied the requirements for courses comprising at least 240 credits of which at least 60 credits were awarded in the second-cycle, or acquired substantially equivalent knowledge in some other way in Sweden or abroad (Higher Education Ordinance 1993:100, Chapter 7, Section 39).

Specific entry requirements for the third-cycle courses and study programme in Horticultural Science. To meet the specific entry requirements the applicant must have the equivalent knowledge to a minimum of 90 credits in relevant subject areas. This must include a degree project, and at least 30 credits must be at the advanced level.

You must also meet the equivalent English language requirements as those necessary for the Swedish upper-secondary qualification Engelska B/6.

You should have received a degree at advanced level (second cycle) within the fields of Horticultural Science, Agricultural Science, or similar subject.

You should also have documented experience with laboratory work and experimental work within the field of study.

Driver’s licence valid in Sweden.

Documented experience from scientific writing and scientific communication.

We are looking for an engaged and self-going candidate with genuine interest in horticulture and circular solutions. Suitable backgrounds are as a Horticulturist or Agronomist. Experience with laboratory work, for example microbial analyses, is beneficial. You should also have experience with practical plant cultivation. Great emphasis will be put on personal skills like curiosity, ability to work individually and in group, and ability to independently plan and perform research related tasks. You are expected to be open to new challenges and to take on various work tasks to contribute to the development of the department’s activities. Very good skills in speaking and writing in English is mandatory.

At the department of Biosystems and Technology you will work in a multi-disciplinary environment together with around 60 colleagues, among which around 10 PhD students. The holder of this position will be a part of a national, transdisciplinary center of excellence called Biogas Solutions Research Center (BSRC). Here, new and relevant knowledge is generated through collaboration between different scientific disciplines as well as between researchers and practitioners from industry and public organizations. The BSRC includes researchers and support from two universities (Linköping University and SLU) and about 50 private and public organizations involving all parts of the biogas system and has additional support from Swedish Energy Agency.

All doctoral positions advertised within BSRC will be formulated so that they fit into the competence center's research plans and at the same time reflect our parties' interests. This way, we ensure long-term competence supply to both industry and academia.

Information about the department: Department of Biosystems and Technology | slu.se

Read more about staff benefits and life as an SLU employee on https://www.slu.se/om-slu/jobba-pa-slu/

Read more about third-cycle courses and study programmes on www.slu.se/utbildning/program-kurser/forskarutbildning/.

Form of employment / FundingEmployment as a doctoral student (4-year programme).Doctoral student’s salaries are set following the local collective agreement. Salary progression is fixed.

Start date:Upon agreement, but preferably 2027-01-01.

Application and selection:Please submit your application using the link below. The deadline is November 27, 2026.

Read more about the attachments that your application should include at https://www.slu.se/en/study/programmes-courses/doctoral-education/how-can-i-become-a-doctoral-student/application/

Selection among eligible applicants is based on the documents attached to the application, and is carried out with regard to the applicant’s ability to complete the programme within the allotted time.

Academic union representatives:

https://internt.slu.se/en/my-employment/employee-associations/kontaktpersoner-vid-rekrytering/

• Reference number SLU.ua.2026.2.5.1-3075
• Publishing date 13 October 2026
• Last date to apply 27 November 2026
• Working hours Day
• Position PhD student
• Occupation area PhD
• Occupation degree Full time
• Employment level Time limited employment (temporary)
• Organizations SLU, Faculty of Landscape Architecture, Horticulture and Crop Production Sciences, Department of Biosystems and Technology

Contact persons

• Karl-Johan Bergstrand
• Senior Lecturer
• +4640415343
• karl-johan.bergstrand@slu.se