Pedology, Soil Science

The lectures are designed to introduce the basic concepts for describing, classifying, and characterizing soils: their various components (minerals, clays, organic matter, living organisms); their physical properties (particle size distribution, texture, structure); chemical properties (clay-humic complex, CEC, redox), and biological properties (soil horizons and humus, root systems, plant nutrition, the role of bacteria, C/N ratio, soil fauna). We will study the factors involved in soil formation (climate, bedrock, living organisms, topography, time), the various processes of soil formation and evolution (weathering, humification, leaching, podzolization, pedoturbation, ferrallitization, etc.), the major soil classification systems, and the distribution of soils around the world. This scientific foundation will enable students to address current societal issues related to soils in the lab sessions: soil degradation (erosion, pollution, land conversion, compaction, etc.) and soil restoration (decontamination, phytoremediation, agroecology).

The field trip will provide an opportunity to apply the concepts covered in class.

Hourly volumes:

CM: 12:00 p.m.

TD: 9 a.m.

Land: 6 hectares

The objective of this module is to establish a foundation of knowledge in pedology and soil science in order to describe, classify, and characterize soils, their physical, chemical, and biological properties, as well as their formation and evolution in various environments.

First-year-level knowledge of general geology: IGN mapping and geological mapping; the external geodynamic cycle (weathering, erosion, transport, and deposition).

• Ongoing Assessment
• Final Exam

Brief description of the concepts covered in fourth grade:

1. Introduction

• Definitions of “soil” (colloquial, literary, scientific)
• The origin of soil: the three stages of formation—weathering, incorporation of organic matter, and nutrient transfer
• Examples of soil diversity (thickness, color, etc.) on a global vs. local scale

2. The building blocks of the floor system

• mineral constituents (from rock minerals to soil minerals; mineralogy of clays)
• organic components (humus-rich litter)
• living organisms (bacteria, fungi, fauna); molecular ecology; cultivable/visible diversity

3. Soil Properties

a) A Physicist's Perspective

• 3 phases: solid, liquid, gas
• grain size (sand, silt, clay)
• structure, porosity, and air
• soil and water (water supply)

b) A Chemist's Perspective

• clay-humic complex
• CEC, pH,
• redox

c) A Naturalist's Perspective

• Profile and Outlook
• Type of humus (O horizon)
• Color and spots, texture, structure, roots, coarse elements, …

4. Soil and Plant Nutrition

• the root system
• Plant Nutrition: From Deficiency to Toxicity, Total vs. Available Nutrients
• Role of microbes: catalyzing decomposition, fate of organic matter, recycling, humification > carbon, nitrogen, and phosphorus cycles
• soil symbioses (mycorrhizae, nitrogen-fixing bacteria)
• Role of soil fauna (earthworms, ants, termites, etc.): soil disturbance, upwelling of mineral elements, incorporation and transformation of organic matter
• In conclusion:
  -- functional feedback on types of humus

-- soil and vegetation distribution (azonality, zonality)

5. Formation, Evolution, Classification, and Global Distribution of Soils

• Factors in soil formation: climate, bedrock, living organisms, topography, time (soil age)
• some processes involved in soil formation and development: weathering, humification, leaching, podzolization, pedoturbation, ferrallitization, …
• Soil classification: diagnostic horizons; major classification systems (CPCS, Référentiel pédologique, Soil Taxonomy, WRB)
• soil distribution on a global scale (climate), national scale (bedrock), and local scale (topography)
• Mediterranean soils

6. Soil Biodiversity and Metal Pollution. Phytoremediation. 

7. Soil Biodiversity and Hydrocarbon Pollution (DNAPL and LNAPL). Phytoremediation

Summary description of the tutorial sessions and the number of hours associated with each session

Six 1.5-hour tutorial sessions will address current issues in soil science and environmental science. Students will be required to analyze scientific articles using the concepts learned in class. The articles will be selected from the following topics:

Session 1: Description of a soil (color, texture, macrofauna, etc.)

Session 2: Soils and the Water Cycle (runoff vs. infiltration, water reserves, evapotranspiration)

Session 3: Soil Degradation – 1: Erosion and Flooding, Land Cover Change, Compaction, and Decline in Organic Matter Content

Session 4: Soil Degradation – 2: Pollution of agricultural soils (pesticides: chlordecone, copper, etc.) and industrial soils (mining sites, hydrocarbons, etc.)

Session 5: Remediation of Contaminated Soils (Decontamination, Phytoremediation)

Session 6: Restoration of Agricultural Soils: Alternatives to Conventional Agriculture (agroecology, agroforestry, permaculture, no-till farming, intercropping, legumes, terra preta)

Description of the topics/hands-on activities covered during your field trip(s) and details on the destinations/sites

• Description of a Typical Mediterranean Soil Profile
• Study of the spatial variability of soils along a toposequence, as a function of topography and bedrock.

Basic knowledge of pedology and soil science

Identification, Characterization, and Specific Functions of the Most Common Soils