Improving access to subsoil properties and knowledge

Nowadays, a significant knowledge gap remains regarding carbon dynamics across soil organic layers, especially the interplay between topsoil and subsoil, and the extent to which soil management practices affect subsoil carbon and related properties. Indeed, the current models used to monitor soils properties dissociate the topsoil functions from subsoil functions, leading to uncertainties of soil properties such as the organic carbon content. The PhD work aims at (1) developing tools and carry out in-situ continuous measurements using sensors created at ARU to improve access to subsoils properties and environmental conditions; (2) develop new indicators based on the analysis of the field samples for measuring short-term C dynamic (labile fraction) of subsoil and link it with agronomic properties (e.g., fluctuations in nutrient availability and environmental interactions) and (3) to understand the top-down and bottom-up processes between the different soil compartments ( organic layer, topsoil and subsoil), regarding carbon dynamics and agronomic properties. To do so, the Ph.D. student will install and operate multi-ion and environmental sensors at the Anglia Ruskin University (ARU) field site to continuously monitor soil nutrients and environmental conditions, and build a high-frequency, real-time dataset for analysis. Laboratory analysis will be performed at IFPEN using ramped thermal analysis (Rock-Eval®) and complementary methods to identify and quantify soil carbon pools across different soil compartments. Finally, integrate field sensor data with laboratory results to evaluate the relationship between short-term nutrient dynamics and long-term soil carbon behavior and develop Rock-Eval® proxies to explore carbon compartmentalization and potential geological influences.
This PhD project is part of the EU Horizon-funded DeepHorizon (DEploying Ecosystemic solutions to imProve soil Health and uncOveRing subsoil functIons in the critical ZONe) initiative, involving 20 partners across Europe. DeepHorizon aims to unlock knowledge of the subsoil in critical zone in order to deploy ecosystemic solutions to improve subsoil functions for soil health.It contributes to Work Package 3 (WP3): "Measuring Subsoil Properties to Identify Indicators and Processes".

Keywords: Soil carbon dynamics, topsoil, subsoil, organic carbon, thermal analysis, spectroscopic analysis, field data

• Academic supervisor    Prof. Chungui LU, Faculty of Science & Engineering, ARU, ORCID: orcid.org/0000-0002-0064-4725
• Doctoral School    Anglia Ruskin University (ARU)
• IFPEN supervisor    Marie-Liesse AUBERTIN, ORCID : orcid.org/0009-0009-3406-1614
• PhD location    IFPEN, Rueil-Malmaison, France and  ARU, Chelmsford, United-Kingdom
• Duration and start date    3 years, starting in early 2026
• Employer    IFPEN
• Funding    EU Horizon-funded DeepHorizon  (Grant Agreement number: 101156701 — DeepHorizon — HORIZON-MISS-2023-SOIL-01) 
• Academic requirements    University Master degree in soil science, environmental sciences, agronomy 
• Language requirements    English level B2 (CEFR) 
• Other requirements    R programming skills would be appreciated

To apply, please send your cover letter and CV to the IFPEN supervisor indicated here below.