Dr. Sarah Thorne, Biology, Sheffield
How can we remove atmospheric carbon dioxide (CO2) to mitigate against climate change and how can we increase food production to support a growing human population? This project aims to address both questions. Over geologic time, rocks are naturally degraded via a process called rock weathering and involves CO2 being removed from the atmosphere and stored as carbonate. Previous work has shown that applying basalt rock dust to agricultural fields accelerates this process and so is a potential CO2 removal strategy. However, it also increases soil pH, which reduces the availability of several important plant nutrients, including silicon. Previous experiments have tested the effects of basalt and silicon separately, but this project will use the legume alfalfa to investigate whether combining silicon fertilisation with basalt applications can be used to simultaneously increase yield and accelerate rock weathering. The student will be trained in a range of laboratory techniques, including how to measure rock weathering and silicon accumulation using XRF spectroscopy. They will also gain experience in plant-soil-microbe interactions, using microscopy to examine growth between alfalfa and its bacterial symbionts. Students will be expected to present their findings orally at a research day in York in September 2024.