pH-D candidate "Role of soil bacteria in access to nutrients by vegetation: isotopic approach"
Université de Strasbourg
The experimental work as well as the elementary and isotopic measurements will be carried out within the Laboratory of HYdrology and GEochemistry of Strasbourg (https://www.lhyges.unistra.fr), and more particularly within the Isotopic Biogeochemistry team and experimental (BIsE; https://www.lhyges.unistra.fr/description-de-l-equipe-BISE). The microbiological aspects will be carried out at the Biology and Cell Signaling Laboratory (https://bsc.unistra.fr/equipes-de-recherche/equipe-schalkmislin/presentation/). The doctoral student will be based at LHyGeS
Geochemistry, Mineralogy, Petrology & Volcanology (GMPV)
Soil System Sciences (SSS)
Role of soil bacteria in access to nutrients by vegetation: isotopic approach
Eighty percent of the Grand Est region is dedicated to agriculture and forestry. From the Vosges mountains to the plains of Champagne, the forest covers almost 2 million hectares, which corresponds to a rate of afforestation of 33% and makes our region one of the most forested regions in France. It is also one of the first agricultural regions in France.
Producing enough plant biomass in a logic of sustainable development for food, housing and energy production for a world population that is constantly growing is a key concern of the 21st century. This observation requires efficient management of the natural fertility of forest and agricultural soils, which is not a renewable source. In addition, in the context of global warming, the Grand Est region has experienced heat waves and droughts in recent years which cause rainfall deficits (20% less precipitation between 2017 and 2019 compared to previous periods, DREAL Grand Est data), which impacts the growth of forest ecosystems and calls for reinforced irrigation for agricultural systems.
Sustainable management of natural soil fertility therefore requires identifying, determining and predicting the evolution of soil nutrient reservoirs and their interactions, as well as understanding the mechanisms that lead to the storage and release of nutrients in a context of global climate change.
The main objective of this doctoral thesis project proposed in co-supervision between the LHyGeS and the BSC, and in collaboration with the IC2MP is to provide a better understanding of the bioavailability of Ca, a macronutrient essential for plant growth, and little studied, in soils and in the mechanisms that make it assimilable by plants. This will include, in particular, experimental batch and mesocosm studies at the water-matrix-organism interface and an innovative isotopic approach of:
1. Set up batch experiments to confirm the role of microorganisms on the isotopic fractionation of Ca during the sorption of Ca on (1a) bacteria and bacterial metabolites and on (1b) manganese oxides (isotopes of Ca)
2. Set up experiments in mesocosms in order to identify the respective role of bacteria, roots, minerals on isotopic fractionations (stable isotope coupling Ca-Sr-N-C, radiogenic Sr).
A.-D. Schmitt, MC HDR (LHyGeS)
V. Geoffroy, MC HDR (BSC)
The candidate will hold a master 2 in environmental sciences / earth sciences or a similar field. He / she will have an appetite for laboratory work (assembly of experimental protocols), isotopic geochemistry (work in a clean room, mass spectrometry with thermo-inization). Knowledge of microbiology and mineralogy will be a plus.
A good command of oral and written English is also required as well as the ability to interact and work in an interdisciplinary field.
Please send me (firstname.lastname@example.org) your CV, cover letter, copies of the license, master 1 and first semester master 2 transcripts as well as the names and contact details of two contact persons for Wednesday 15 April. A first selection will be made and a candidate will be proposed to apply to the doctoral school (in May, with oral in early June).
Do not hesitate to contact me (email@example.com) if you would like more information on the subject or on the terms of the competition.