Applicants are invited for a PhD fellowship/scholarship at Graduate School of Technical Sciences, Aarhus University, Denmark, within the Agroecology programme. The position is available from 01 November 2026 or later. You can submit your application via the link under 'how to apply'.
Title:
The Ecology of seed decay: plant-soil-microbe interactions for weed suppression in agroecosystems
Research area and project description:
Background.
The soil seed bank is the main reservoir of weed and arable plant diversity in agroecosystems. The longevity of seeds in the soil seed bank is a major determinant of the persistence and dynamics of weed populations. The dynamics of soil seed bank decline can be explored using the ‘epidemiological triad’ model which assumes that environmental (soil*cropping system interactions), host (seed defence traits) and agent (soil microbiome) interact to determine rates of seed degradation and persistence in agricultural soils. In a One Crop Health context, this model posits that regulation of the size and composition of arable weed populations and communities by soil microbial communities is enhanced in healthy soils.
Hypotheses.
H1. The rate of seed decline (loss of seed viability) in agricultural soils is impacted by interactions between soil characteristics, soil and crop management, weed species identity and soil microbial community composition.
H2. Rates of seed decline of common Danish weed species vary across a gradient of agricultural soil type and soil management intensity.
H3. The epidemiological triad for seed decay provides a predictive framework for the design of weed-suppressive soils that can regulate the population dynamics of weed species.
Objectives.
You will conduct plant ecological experiments in agricultural fields and glasshouse mesocosms. You will develop skills and competencies in seed and plant ecology, microbial ecology and metagenomics, and the analysis of multivariate data (soil-plant-microbe-environment) to unravel the dynamics of seed decay in agricultural soils. Specific objectives include:
- Identify a subset of cropped fields in the Danish One Crop Health farm network with contrasting weed communities, soil types, and cropping intensities (crop rotation, tillage, pesticide use).
- Perform glasshouse and field seed burial experiments, and laboratory seed aging experiments to explore the longevity of seeds of common weed species in contrasting soil types.
- Characterize the soil microbiome and seed-associated microbiome and its role in regulating seedbank dynamics in the soil in contrasting agricultural soils.
- Conduct glasshouse mesocosm experiments to explore the impacts of soil sterilisation and manipulation of soil microbial communities (addition of synthetic microbial communities) on the longevity and germination of buried weed seeds and on the dynamics of weed communities.
Novelty & timeliness.
Relatively little is known about soil-seed-microbe interactions in the context of soil seedbank dynamics. Interests in regenerative agriculture, soil health, plant growth promoting ‘biologicals’ and reductions in pesticide use will all impact plant-soil-microbe interactions. This project seeks to enhance understanding of plant-soil microbiome interactions for regulating weedy and arable plant communities towards a better understanding of the potential for weed-suppressive soils in healthy agroecosystems.
Project description. For technical reasons, you must upload a project description. Please simply copy the project description above and upload it as a PDF in the application.
Qualifications and specific competences:
Applicants to the PhD position must have a relevant master’s degree in plant ecology or agricultural science.
Further requirements:
- Research experience in weed ecology and management, and in methods and techniques in seed science.
- Proficiency in use of R for analysing and modelling ecological data.
Place of employment and place of work:
The place of employment is Aarhus University, and the place of work is Department of Agroecology, Section for CROP HEALTH, Forsøgsvej 1, 4200 Slagelse, Denmark.
Contacts:
Applicants seeking further information regarding the PhD position are invited to contact:
- René Gislum, rg@agro.au.dk (main supervisor)
- Virginia Anne Nichols, gina.nichols@agro.au.dk (co-supervisor)
For information about application requirements and mandatory attachments, please see our application guide. If answers cannot be found there, please contact:
How to apply:
Please follow this link to submit your application.
Application deadline is 05 August 2026 at 23:59 CEST.
Preferred starting date is 01 November 2026.
Please note:
- Only documents received prior to the application deadline will be evaluated. Thus, documents sent after deadline will not be considered.
- The programme committee may request further information or invite the applicant to attend an interview.
- Shortlisting will be used, which means that the evaluation committee only will evaluate the most relevant applications.
Aarhus University’s ambition is to be an attractive and inspiring workplace for all and to foster a culture in which everyone has opportunities to thrive, achieve and develop. We view equality and diversity as assets, and we welcome all applicants. All interested candidates are encouraged to apply, regardless of their personal background. Salary and terms of employment are in accordance with applicable collective agreement.
INFORMATIONER OM STILLINGEN:
- Arbejdspladsen ligger i:
Slagelse Kommune
-Virksomheden tilbyder:
-Arbejdsgiver:
Technical Sciences - Institut for Agroøkologi, Forsøgsvej, 4200 Slagelse
-Ansøgning:
Ansøgningsfrist: 05-08-2026;
Se mere her: https://job.jobnet.dk/find-job/407254ec-089a-4508-986b-b54f76c4e0d9
