ESF-CUC PhD Studentship Opportunity
The perfect soil: an investigation of the chemical
characteristics needed for healthy, artificial soils at
the Eden Project, Cornwall
Dr Mark Fitzsimons, University of Plymouth; Dr Tim Pettitt, Eden Project; Dr Gavyn
Rollinson, Camborne School of Mines, University of Exeter
Description of the study:
Soil consists of loose weathered rock debris and decayed organic material.
Mature soil with a robust capacity to retain plant nutrients normally takes thousands
of years to form. This project looks at manufactured soil, building on expertise
accumulated by the Eden Project (EP), with the overall aim to produce artificial soil
from waste materials that can maintain a reservoir of slow-release nitrogen to sustain
growth without the high demand for fertilizer application associated with the majority
of manufactured soils currently used at EP. The project will begin by characterizing
materials used by EP for mineral content and structure, nitrogen content and
speciation (inorganic or organic nitrogen) together with some extant EP soils of
varying properties. Soils will then be made and weathered under different climate
regimes and treatments, in bioreactors (e.g. soil columns) to measure changes in
nitrogen speciation over time, and the role of mineralogical structure in nitrogen
retention. The most promising soils will be further refined after reviewing the initial
data, to improve performance where possible, and then tested under different biome
conditions and also simulated extreme events, such as desiccation and intense
rainfall, to assess the robustness of the soil nitrogen reservoir. The project brings
together scientists with expertise in nitrogen cycling and speciation, mineralogy and
soil manufacture and ecology, applying state-of-the-art analytical techniques that will
enhance the ability of the EP to produce a sustainable and commercial product. This
will bring EP, and the locality, significant benefits in terms of personnel skills,
sustainability and commercial potential.
The PhD student will be trained in the analysis of nutrients and metals, and will
contribute to method development through design of the bioreactors and extraction
techniques.
Entry requirements:
This project would be suitable for students holding, or expecting to achieve, at least
a 2:1 honours degree in chemistry, environmental science, earth science, soil
science or another related discipline.
Funding:
The studentship is supported for three years from 1 October 2011 and includes full
Home/EU tuition fees and a stipend of £13,590 p.a. (tax free).
Application procedures:
For an application form, and full details on how to apply, please visit
www.plymouth.ac.uk/postgraduate. In order to apply you will need to complete the
standard postgraduate application form along with a covering letter detailing
suitability for the individual studentship. In section 9 of the application form (Funding
Information) please ensure that you declare that you are applying for an ESF-CUC
Studentship.
On completion send your application form to Catherine Johnson, Faculty of
Science and Technology Research Office, Room A103, Portland Square, Plymouth
PL4 8AA or e-mail catherine.johnson@plymouth.ac.uk.
Further information on the terms and conditions of a PhD at the University of
Plymouth can be found on www.plymouth.ac.uk/graduateschool.
For an informal discussion please contact Dr Mark Fitzsimons at
mfitzsimons@plymouth.ac.uk.
Closing date for applications: 12 noon, Friday 3 June 2011
Further Particulars
Soil formation occurs and proceeds at a faster rate in the presence of biota.
Although plants can build organic molecules by photosynthesis, elements other than
carbon, hydrogen and oxygen must be obtained from the soil. The ions needed for
building organic molecules are sequestered in the crystal structure of minerals and
soil becomes a source of nutrients as the minerals weather and bedrock breaks
down. Decomposition processes, favoured by the ability of soils to hold moisture and
moderate temperatures, are responsible for recycling nutrients. By promoting
decomposition while retaining nitrogen and other nutrients, the soil prevents rapid
loss of essential elements to groundwater and rivers. This results in a net
accumulation of bioavailable nutrients in the soil and enhanced productivity at all
trophic levels.
The Eden Project manufactures its own soils for use in its biomes, by recycling raw
materials sourced in Cornwall. The performance of soils used in the biomes is
variable and the reasons for this are not fully understood. These soils all follow a
similar basic recipe, using china clay waste sand as the primary inorganic fraction.
Their capacity of the soil to hold plant nutrients was not a prime consideration as it
was initially planned to maintain plant nutrition by carefully-controlled fertilizer
applications. However, after 10 years of hugely variable environmental conditions,
plantings, fertilizer practices, incidental introductions of micro- flora and micro- and
meso-fauna, as well as general husbandry (mulching and allowing natural organic
matter turnover), some EP soils are giving better performance in terms of nutrient
storage than was originally anticipated, whilst others are still quite poor. This range
of soils and environments provides an opportunity to look more closely at the
possibility of developing ‘low-maintenance’ artificial soils in terms of their nitrogen
reservoir, cation exchange capacity and ability to retain and recycle nitrogen
compounds.
Interestingly, china clay waste sand appears to be an excellent base for creating a
soil/growing medium. The capacity for detailed mineral and nutrient analyses,
especially nitrogen, is very limited at EP and access to advanced analytical facilities
in a focussed project would be hugely advantageous.
This project will be framed around the following research question: “How does soil
composition effect the bioavailability of its nitrogen reservoir and, therefore, its ability
to become a self-sustaining soil?”
We have these Aims & Objectives:
Aim:
To develop a fertile, artificial soil with a large reservoir of slow-release nitrogen that
meets the nutrient requirements of the soil.
Objectives:
1. To characterise the raw materials currently used to manufacture soils at the
EP using appropriate analytical techniques (e.g. microscopy, elemental
analysis).
2. To construct soil bioreactors where the performance of soils can be measured
in terms of key characteristics (e.g. nutrient retention, organic content).
3. To use different amendments on the soils being tested to see how this affects
the sustainability of the nitrogen reservoir.
4. To measure the performance of the differently-amended soils under the biome
conditions used at the EP.
5. To produce a protocol for the manufacture of an N-rich soil that can be utilised
from waste materials available in Cornwall and which has wide application for
local projects.
The project brings together experts in nutrient research and mineralogical studies, to
build on the biological/microbiological expertise available at the Eden Project (EP)
and advance understanding of the characteristics of the soils that the EP has
manufactured to date, relating this to their functionality.
Description of research
The project will progress in logical stages dependent on the experiments and
analyses needed to logically address the research question and meet the aims and
objectives of the project.
Outline Work programme:
Year 1 Months 0-6: Training in sampling and laboratory techniques (SKALAR
nutrient analyzer, Shimadzu TOC/TN analyzer, ammonium analysis by fluorescence,
metal digest using lithium borate; metal analysis by ICP-AES and ICP-MS;
Months 6-12: Characterisation of raw materials and established soils to determine
mineral structure and nitrogen bioavailability; microscopy analysis of samples to
select samples of interest for QEMSCAN high resolution structural analysis
End of Year 1: Review of analytical data for preparation of soil preparation and
treatment experiments in Year 2
Year 2 Months 12-18. Set up bioreactors using different material mixtures and
amendments as agreed at review meeting, and perform time-resolved sampling
according to rate of soil maturity; test nitrogen reservoir of amendments used;
Months 18-24. Select best performing soils for analysis of mineral structure using
QEMSCAN for high-resolution mineralogical analysis of structure;
End of Year 2: Review of analytical data to determine further experiments necessary
(e.g. refinements of soil material mix, amendments, testing of soil in different biomes)
Months 24-30: Accumulation of further experimental data as guided by Year 2
Review;
Months 32-36 Thesis write-up.
Key Aspects of Research Training for the Student:
The PhD student will be trained in the analysis of nutrients and metals, and will
contribute to method development through design of the bioreactors and extraction
techniques. While the experimental work will be carried out the the EP, both the UoP
and CSM analytical facilities are close by so that the students can easily organise
sample analysis, having only a short distance to travel to both institutes.
This is a full collaboration with the Eden Project and CUC partner (Camborne School
of Mines, University of Exeter), with the research question being guided by the
experience of the EP in their manufacture and application of soils in the biomes. Dr
Tim Pettitt, is a microbiologist and Assistant Curator of Science Team at the EP and
has been conducting research into the biological colonisation of artificial EP soils for
6 years. Dr Rollinson is an expert in the use of QEMSCAN, an advanced automated
scanning electron microscope that analyses inorganic samples such as rock and soil
(the only instrument of its type in a university in Europe and one of four in a
university globally). Dr Fitzsimons is an expert in nutrient (particularly nitrogen
speciation) and organic geochemistry and has developed analytical techniques to
study nitrogen in a range of challenging environmental matrices.