DEFRA-NCAS Studentship: Exploring the Air Quality Impacts of Emerging Fertilisers

About the Project

Agriculture is a major source of atmospheric pollutants, emitting substantial amounts of ammonia (NH3), greenhouse gases and volatile organic compounds (VOCs). These emissions influence local and regional air quality, climate, and human health. As global food demand grows, fertiliser use is expected to continue rising, with artificial fertilisers currently supporting around half of global food production. At the same time, environmental pressures and concerns around supply-chain resilience are accelerating a shift toward organic and bio-based fertilisers.

While most emission reduction strategies to date have focused on greenhouse gases and ammonia, other pollutants remain poorly characterised. Recent evidence shows that some organic fertilisers emit complex mixtures of VOCs, which can undergo atmospheric oxidation to form secondary organic aerosol (SOA). SOA contributes to particulate matter (PM) which impacts air quality and human health. However, VOC emissions from newer fertiliser products—and their potential to form SOA—are poorly characterised. As the agricultural sector transitions toward organic and bio-fertilisers, understanding whether these products mitigate or exacerbate air quality impacts is critical for evidence-based policy and sustainable farming.

This PhD project will deliver a laboratory assessment of VOC emissions and SOA formation from a suite of conventional, organic and bio-fertilisers. The student will carry out controlled soil-plant chamber experiments to quantify emission factors and chemical fingerprints using advanced mass spectrometric techniques. Additionally, emissions will be introduced into an oxidation flow reactor to simulate atmospheric chemical processing. This will enable quantification of SOA yields and direct comparisons across fertiliser types to assess their relative contributions to air pollution.

This project is well suited to applicants with backgrounds in atmospheric or environmental science, chemistry, physics, environmental engineering or related fields and to those who have an interest in experimental science and environmental policy. It is expected that the scientific outcomes of this work will advance our understanding of emissions from emerging fertilisers and as such this PhD offers a unique opportunity to contribute to national priorities on sustainable agriculture and Net Zero targets. Furthermore, this project will enable the student to acquire skills in data analysis and visualisation, experimental planning, working across disciplines, science communication and engaging with stakeholders.

The University of Manchester provides a world-leading research environment, particularly in atmospheric science. The project will be based within the Centre for Atmospheric Science, supported by state-of-the-art laboratory infrastructure. The supervisory team, led by Dr Aristeidis Voliotis, brings extensive expertise in trace gas measurements, VOC chemistry and agricultural emissions. The student will also have an opportunity to spend time work-shadowing or undertaking a placement in the DEFRA air quality teams towards the end of their project.

Dr Aristeidis Voliotis and Dr Emily Matthews (aristeidis.voliotis@manchester.ac.uk; emily.matthews@manchester.ac.uk) would be pleased to discuss this research project further with interested candidates.

Entry requirement

The standard academic entry requirement for this PhD is an upper second-class (2:1) honours degree in a discipline directly relevant to the PhD (or international equivalent) OR any upper-second class (2:1) honours degree and a Master’s degree at merit in a discipline directly relevant to the PhD (or international equivalent).

Before you apply

We strongly recommend that you contact the supervisors for this project before you apply. Please include details of your current level of study, academic background and any relevant experience and include a paragraph about your motivation to study this PhD project.

Funding

This 3.5-year PhD project is fully funded and home students, and EU students with settled status, are eligible to apply. The successful candidate will receive an annual tax-free stipend set at the UKRI rate (£20,780 for 2025/26) and tuition fees will be paid. We expect the stipend to increase each year. The start date is October 2026.

We recommend that you apply early as the advert may be removed before the deadline.

How to apply

You will need to submit an online application through our website here: https://uom.link/pgr-apply

When you apply, you will be asked to upload the following supporting documents:

• Final Transcript and certificates of all awarded university level qualifications
• Interim Transcript of any university level qualifications in progress
• CV
• You will be asked to supply contact details for two referees on the application form (please make sure that the contact email you provide is an official university/ work email address as we may need to verify the reference)
• Supporting statement: A one or two page statement outlining your motivation to pursue postgraduate research and why you want to undertake postgraduate research at Manchester, any relevant research or work experience, the key findings of your previous research experience, and techniques and skills you’ve developed. (This is mandatory for all applicants and the application will be put on hold without it.
• English Language certificate (if applicable). If you require an English qualification to study in the UK, you can apply now and send this in at a later date.

If you have any queries regarding making an application please contact our admissions team FSE.doctoralacademy.admissions@manchester.ac.uk