Alternative grassland management practices could improve productivity and help mitigate climate change. Grasslands play an important role in building soil fertility for sustainable development1 and the manipulation of grazing practices may increase soil carbon (C) sequestration through higher rhizodeposit-C and animal excreta inputs that have come about through improved soil fertility and more nutrient efficient plants.
Recently mob grazing grassland management has been increasingly promoted by farmers as a way of increasing soil health and C storage. There is, however, a lack of robust scientific evidence to support these claims, particularly in UK grassland systems. Mob grazing is “short duration, high density grazing with a longer than usual grass recovery period,” where a large group of cattle are moved regularly and grass is left to recover for between 40 and 100 days2. Grasslands of different productivity tend to have distinctly different rates of soil C cycling and at appropriate intensity, grazing is thought to promote root growth which puts more C underground. Determining the potential of mob grazing for increasing soil health, C storage and predicting future changes requires knowledge of ecological responses and complex soil processes within grassland management systems.
Overall this project will use carefully selected grassland sites offering contrasting grazing management regimes on comparable soil types to assess productivity, soil health and C storage, nutrient cycling and ecological responses to mob grazing practices. It will explore the benefits that mob grazed vs traditional (set-stocked) grassland systems bring in terms of ecosystem services. Robust laboratory experiments using isotopic tracers will be designed to track C flow and investigate C cycling within contrasting grassland management systems. Interdisciplinary biological, chemical and physical techniques will be used to holistically assess soil health within contrasting grassland systems. Novel investigations will also test the application of 210Pb and 137Cs radioisotope techniques (indicators of grassland soil mixing and disturbance) alongside both non-destructive (e.g. plant ecology, in situ root and soil structure evaluation) and destructive (soil C, nutrient status, microbiology) assessments to increase our understanding of soil processes and C and nutrient storage within these systems.
1. Chenu et al. 2019. Soil & Tillage Research. DOI:10.1016/j.still.2018.04.011.
2. Soil association. https://www.soilassociation.org/our-work-in-scotland/farming-for-the-future/scotland-farming-news/2018/june/12/what-is-mob-grazing-anyway/
The student will be trained in a range of interdisciplinary field and laboratory techniques (e.g. gas chromatography and stable- and radio-isotope approaches). The student will produce a report outlining plans in year 1 and a thesis plan in year 2. Dissemination of research to the wider community through oral and poster presentations annually at international and postgraduate conferences is also required. Data collection should be completed by the end of year 3 and a thesis submitted by year 4, followed by an oral examination. Progress reports (9 months and annual) summarising project progress, training and conference activities are completed. Collectively supervisors on this project have many years of extensive PhD supervision experience and the student’s training needs will be monitored carefully. The student will be encouraged to attend courses provided through the Institute for Academic Development as appropriate.
Applicants should download the required forms from http://www.eastscotbiodtp.ac.uk/how-apply-0
and send the following documents to [email protected]
a. EASTBIO Application Form
b. EASTBIO DTP Equality Form
d. Academic transcripts (a minimum of an upper second class or first class honours degree or equivalent is required for PhD study
e. Two references should be provided by the deadline using the EASTBIO reference form (http://www.eastscotbiodtp.ac.uk/how-apply-0
). Please advise your referees to return the reference form to [email protected]
f. If you are nominated by the supervisor(s) of the EASTBIO PhD project you wish to apply for, they will provide a Supervisor Support Statement.
This 4 year PhD project is part of a competition funded by EASTBIO BBSRC Doctoral Training Partnership View Website. This opportunity is only open to UK nationals (or EU students who have been resident in the UK for 3+ years immediately prior to the programme start date).
The studentship covers fees, stipend, research training support costs of £5,000 per year (this is reduced to £1,500 in the final year) and a small travel and conference allowance.