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Transcript of Calibration and testing of a pedogenesis model: emphasis ... · PDF file I am especially...

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    Travail de Fin d'Études

    Du Avril 2012 au Septembre 2012

    María Suárez Bonet

    3ème année promotion 2012

    Parcours Fluides : Energie, Transport, Environnement, Santé

    Géochimie des Sols et des Eaux Aix en Provence

    France

    École Centrale Marseille Marseille FRANCE

    Calibration and testing of a pedogenesis model: emphasis on clay migration

    Tuteur école : Fabien Anselmet

    Tuteur entreprise: Sophie Cornu

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    RÉSUMÉ L’objectif principal de mon stage dans l’unité de recherche Géochimie des Sols et des Eaux (GSE) était de calibrer une nouvelle version de SoilGen, un model de pédogénèse qui simule le lessivage, et de tester sa sensibilité à des changements de pratiques agricoles et d’utilisation du sol. Le lessivage est un processus considéré comme très important dans l’évolution des sols. Par contre, pour le moment il y a un manque de modélisation du processus. En outre, les activités humaines ont des répercussions importantes dans les sols. L’agriculture et le changement climatique sont quelques exemples. Si on veut assurer que les sols continuent à remplir ses fonctions, il est essentiel pour pouvoir modéliser et prédire leur évolution. ABSTRACT The main objective of this internship in the laboratory of Soil and Water Geochesmitry (GSE) was to calibrate a new version of SoilGen, a pedogenesis model that simulates clay migration, and to test its sensibility to changes in agricultural practices and landuse. Indeed, while clay migration is considered to have a leading role in soils evolution, there is an evident lack of modelisation of the process. Furthermore, human activities have important impacts in soil. Agriculture or climate change are some examples. This makes it essential to be able to model and predict soils evolution if we want to ensure that they will continue to fulfill their functions. KEY WORDS Clay migration - SoilGen - Calibration - Climate - Agriculture

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    In the context of my internship I would like to be grateful to all the staff of the laboratory of Soil and Water Geochesmitry (GSE). They were always helpful and assisted me in the resolution of my task all along my internship. I am especially grateful to my tutor in the laboratory, Sophie Cornu. I learned a lot from her, not only in what refers to the theoretical basis needed to develop my tasks, but also in what refers to getting to know the world of scientific research. Finally, I am also especially grateful to Peter Finke, developer of the model SoilGen. His assistance was essential during the development of my job.

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    TABLE OF CONTENTS PART 1

    1. THE LABORATORY OF SOIL AND WATER GEOCHEMISTRY (GSE) ......................................... 5

    2. PRESENTATION OF THE MISSION ...................................................................................... 7

    2.1. Context ............................................................................................................................... 7

    2.2. The missions ....................................................................................................................... 8

    PART 2

    1. PRESENTATION OF SOILGEN ............................................................................................. 9

    1.1. Main processes in SoilGen ................................................................................................. 9

    1.2. Processes related clay migration ..................................................................................... 10

    2. CALIBRATION OF SOILGEN FOR LESSIVAGE ..................................................................... 14

    2.1. Starting point .................................................................................................................... 14

    2.2. Calibration approach: ....................................................................................................... 15

    2.3. Results of the calibration ................................................................................................. 17

    2.3.A. Calibration of h(θmacro) .............................................................................................. 18

    2.3.B. Calibration of n .......................................................................................................... 18

    2.3.C. Calibration of Ps,max and B .......................................................................................... 19

    3. SOILGEN’S SENSIBILITY TO CHANGES IN AGRICULTURAL PRACTICES AND LANDUSE ......... 23

    3.1. Description of the experimental sites .............................................................................. 23

    3.1.A. Feucherolles .............................................................................................................. 24

    3.1.B. Mons ......................................................................................................................... 26

    3.1.C. Boigneville ................................................................................................................. 26

    3.2. Climate data ..................................................................................................................... 27

    3.2.A.Temperature .............................................................................................................. 27

    3.2.B. Annual precipitation.................................................................................................. 30

    3.2.C. Potential evapotranspiration .................................................................................... 32

    3.2.D. Rainwater composition ............................................................................................. 34

    3.3. The plant module and organic matter ............................................................................. 35

    3.3.A. Dynamic of the vegetal cover depending on the type of plant ................................ 35

    3.3.B. C-input to the soil depending on the type of plant ................................................... 37

    3.4. Bioturbation ..................................................................................................................... 41

    3.5. Parent material................................................................................................................. 42

    4. CONCLUSIONS AND OUTLOOKS ...................................................................................... 44

    BIBLIOGRAPHIE ................................................................................................................. 45

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    PART 1: INTRODUCTION

    1. THE LABORATORY OF SOIL AND WATER GEOCHEMISTRY (GSE) The laboratory of Soil and Water Geochesmitry (GSE) is a research unity part of the French National Institute for Agricultural Research (INRA). INRA’s principal role in agricultural research is not only limited to France. Indeed, it is the main agricultural research institute in Europe and the second one in the world. Research carried out in this institute has as objective high quality and healthy foods, the development of competitive and at the same time sustainable agriculture with a constant regard in its effects on the environment. Issues addressed by INRA are at a national and international level. Most of the research employees are scientists and engineers. INRA cooperates closely with universities, giving lectures mostly in master degrees and with internships. INRA consists of several research unities all around France, organized in 14 research divisions:

    - Nutrition, Chemical Food Safety and Consumer Behavior - Plant Biology - Science and Process Engineering of Agricultural Products - Forest, Grassland and Freshwater Ecology - Environment and Agronomy - Animal Genetics - Plant Breeding and Genetics - Applied Mathematics and Informatics - Microbiology and the Food Chain - Animal Physiology and Livestock Systems - Animal Health - Plant Health and Environment - Science for Action and Development - Social Sciences, Agriculture and Food, Rural Development and Environment

    The laboratory of Soil and Water Geochesmitry (GSE) is part of the division "Environment and Agronomy" and contributes to the Pole "Adaptation to Global Change" of INRA’s research center Provence-Alpes-Cote d'Azur.

    GSE is located in the techno-environmental cluster Technopôle de l’environnement Arbois- Mediteranée, in Aix en Provence. It was founded in 2001 and nowadays it employs 9 people among scientists and technicians, secretary staff and PhD students. Their research activities are mainly focused on

    biogeochemical processes in agrosystems and ecosystems and their thermodynamic and

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    kinetic modeling with the aim of predicting and assessing on the impact of human activities and climate change on soil quality. The research approaches include isotopic tracing of soil carbon at a molecular level and continuous analysis of geochemical properties of soil and water. During my internship, I was able to see how a research unity works from the interior and to have a first contact with the scientific research world.