Improving carbon uptake in soils by designing ‘carbon fertilisers’: Computational and experimental study

Lead supervisor: Dr Natalia Martsinovich, Chemistry
Co-supervisor(s): Dr María Romero-González, Geography

Deadline: Thursday 23 February 2017

Applications for this project have now closed.

Soils contain large amounts of organic matter (also called “soil organic carbon”). Carbon in soil is important for capturing carbon dioxide from the atmosphere, for growing crops, and more broadly for maintaining the stability of soils. However, carbon is being lost from soils because of the increase in intensive agriculture. It is therefore essential to keep replenishing the carbon content, similar to the addition of fertilisers to increase nutrients in soil.

The aim of this project is to identify carbon-based molecular structures that bind most strongly to oxide minerals in soil. These molecules will be the most likely candidates for “carbon fertilisers”.

The student will use a combination of spectroscopic measurements and theoretical calculations to study the binding of organic molecules to typical minerals found in soil. The aim is to identify naturally abundant molecules that bind strongly to minerals – the candidates for good carbon uptake and storage in soil.

Previous research on organic matter uptake in soil showed that presence of iron and aluminium oxyhydroxides improves the binding of carbon to soils: on average, 20% of soil organic carbon is bound to iron minerals. While it is not possible to change the composition of soil on a large scale (e.g. whole fields) by adding carbon-binding minerals, there is a possibility of choosing a suitable organic carbon “fertiliser” which binds strongly to these soil minerals.

You will study the binding of organic molecules (from small model molecules to large naturally occurring biomolecules) to typical minerals found in soil, such as hematite (iron oxide). For example, polysaccharides – long-chain organic molecules abundant in plants and animals – are good candidates for carbon source materials. They contain a variety of organic functional groups: glucose rings, hydroxyl and amide groups, which make them promising candidates to bind to soil minerals.

You will use both theoretical (density-functional theory) and experimental methods (surface-sensitive spectroscopy). The project will be coordinated by two supervisors with expertise in the theoretical (Dr Natalia Martsinovich) and experimental (Dr María Romero-González) aspects of the research. You will join the vibrant PhD communities in the Departments of Chemistry and Geography at the University of Sheffield.

This project is funded by the Grantham Centre for Sustainable Futures. In addition to research work, you will participate in the Grantham Scholars PhD training programme, which has been designed to help you develop awareness of sustainability and learn to engage with the media, industry and policy-makers to promote sustainability and environment matters.

Keywords: chemistry, materials, sustainability, theory, spectroscopy

Subject areas: Agricultural Chemistry, Computational Chemistry, Environmental Chemistry, Geochemistry, Materials Science, Applied Physics, Agronomy and Soil Science

Funding notes

This four-year studentship will be fully funded at Home/EU or international rates. Support for travel and consumables (RTSG) will also be made available at standard rate of £2,627 per annum, with an additional one-off allowance of £1,000 for a computer in the first year.  Students will receive an annual stipend of £17,336.