Supervisors:
Professor David Burslem - University of Aberdeen, School of Biological Sciences - [Email Address Removed]
Dr Gareth Norton - University of Aberdeen, School of Biological Sciences - [Email Address Removed]
Professor Paul Hallett - University of Aberdeen, School of Biological Sciences - [Email Address Removed]
Tea is consumed in greater quantities and by more people globally than any other beverage apart from water. Global production of tea was 6 million tons in 2018, increasing by 4.7% annually. Tea consumption is an important component of the UK’s global footprint from agriculture: over two-thirds of the population drinks one or more cups per day, amounting to annual per capita consumption of ~2 kg. UK production of tea is small (~ 30 growers, mostly in Scotland), but has potential to increase with climate warming.
Tea grows best on tropical acidic soils (pH < 5.0) that naturally display high phytotoxic Al3+ and low concentrations of important nutrients for plant metabolism. Inorganic fertilizer use tends to be high, leading to steep declines in soil health indicators in newly established tea plantations. This studentship will address the fundamental mechanisms underpinning sustainable nutrient and soil management of new tea plantations in Scotland, which possess distinctly different soil chemical and physical properties to those in the tropics.
One attribute of tea relevant to nutrient capture is its unusual capacity to hyper-accumulate Al, in contrast to most crop plants which avoid phyto-toxicity symptoms by excluding Al. Al addition to tea causes up-regulation of photosynthesis, and increased synthesis and exudation of organic acids by roots. This is important because organic acids detoxify Al3+ ions by chelation prior to uptake and during transport within the plant. Our hypothesis is that root exudates of tea function to modify rhizosphere pH, leading to increased dispersion of soil colloids and dissolution of limiting nutrient cations for plant uptake. The dispersion of soil colloids may also increase the availability of Al3+ ions, generating a demand for detoxification via organic acid chelation. The acidic, highly-weathered soils underlying tropical tea plantations are structurally unstable, which may be exacerbated if Al uptake or chelation alters bonding between soil particles, but Al dynamics in less weathered Scottish soils are likely to be different.
The chemical composition and function of tea root exudates are unknown. This project will use advanced analytical techniques to (a) characterise the chemical constituents of tea root exudates, (b) test the effects of organic acid constituents on rheological dispersion and cation release across different soils, and (c) examine effects of organic amendments and liming in controlled environment and field conditions. Training will be provided in relevant techniques in soil science and plant physiology, experimental design, project planning and statistical analysis.
It may be possible to undertake this project part-time, in discussion with the lead supervisor, however, please note that part-time study is unavailable to students who require a Student Visa to study within the UK.
Application Procedure:
Please visit this page for full application information: http://www.eastscotbiodtp.ac.uk/how-apply-0
Please send your completed EASTBIO application form, along with academic transcripts to Alison Innes at [Email Address Removed]
Two references should be provided by the deadline using the EASTBIO reference form.
Please advise your referees to return the reference form to [Email Address Removed]
Unfortunately due to workload constraints, we cannot consider incomplete applications