88374 - Soil Chemistry and Carbon Cycle

Academic Year 2022/2023

  • Teaching Mode: Traditional lectures
  • Campus: Bologna
  • Corso: Second cycle degree programme (LM) in Low Carbon Technologies and Sustainable Chemistry (cod. 9246)

Learning outcomes

Soil component and chemistry of the finest fractions: clay minerals, oxy-hydroxides, humic substances. Cycles of organic carbon and nitrogen. Strategies to increase C sink: recycling of agricultural, forest, agro- industrial and urban biomasses. Behavior of pollutants in the soil-water-plant ecosystem according to their chemical-physical characteristics. Adsorption, accumulation and biotic and abiotic transformations of pollutants at rhizosphere level and vegetable absorption.

Course contents

A) Pre-skills

Students attending this course should possess a background on environmental chemistry and soil chemistry. Students should gain familiarity with the use of electronic spreadsheets for data handling before the course.

B) Didactic units

The course is divided into four didactic units.

UNIT 1. Introduction to soil chemistry (2 hours)

The soil environment. Chemical reactions in the soil. Soil biogeochemical cycling. Soil and environmental health.

Knowledge gained in Didactic Unit 1:

  • Soil definition
  • Soil interaction with other environmental compartments

UNIT 2. Soil components and properties (14 hours)

2.1 Characteristics of chemicals in soil. Occurrence of elements in soil. Essential elements. Inorganic contaminants. Anthropogenic organic chemicals. Properties of the elements in soil.

2.2 Fluid phases. Soil water chemistry: components in the soil solution, acids and bases, gas dissolution, precipitation and dissolution reactions, cation hydrolysis, complexation - Soil air chemistry: components in the soil air, soil redox processes, redox potential limits in natural systems.

2.3 Solid phase. Inorganic (mineral) components: minerals (common soil minerals, crystal chemistry of minerals, silicates, carbonates, phosphates), chemistry of soil clays. Organic components: components in soil organic matter (SOM), ecosystem carbon storage and fluxes, SOM formation factors, function of organic matter in soil.

2.4 Surfaces’ properties of soil colloids. Permanent charge, pH-dependent charge, adsorption processes (outer-sphere, inner-sphere, non-charged chemicals, desorption), cation exchange, predicting sorption processes in soils.

Knowledge gained in Didactic Unit 2:

  • Main mineral and organic soil components
  • Main soil water reactions
  • Main redox reactions in soils
  • Main surfaces’ properties of soil colloids

UNIT 3. The carbon cycle (12 hours)

3.1. The biogeochemical cycle of carbon. The global carbon inventory and cycle. Long-term and short-term carbon cycle. Connections between carbon and the nitrogen and oxygen cycles.

3.2 The carbon sink in the soil. The carbon sequestration in soils. Soil organic carbon (SOC) stocks. SOC increasing and protecting measures. Recycling of agricultural, agro-industrial and urban biomasses (animal manure, compost, sewage sludge, biochar) as organic amendments.

Knowledge gained in Didactic Unit 3:

  • Global carbon inventory dimensions and fluxes
  • Main measures to increase the soil organic carbon
  • Recycling of organic biomasses in agriculture

UNIT 4. Seminars and exercises (14 hours)

4.1 Seminars. A cycle of seminars with invited speakers focused on key topics of the course will be organized.

4.2 Exercises. Individual and/or group exercises will be held in the classroom. During the exercises, practical tasks on key topics of the course will be assigned to be solved individually or in group.

Readings/Bibliography

The didactic material will be provided by the teacher and made available on-line (IOL), specific readings will be indicated during the course.


Suggested textbooks:


Blume et al. (2016), SOIL SCIENCE, Springer (chapters: 1-3, 5 and 10).


Strawn et al. (2020), SOIL CHEMISTRY 5th edition, Wiley.

Teaching methods

The course is divided into three parts:


1. Frontal lessons: through didactic unit explanations, students should gain knowledge of the main instruments available on key topics of soil chemistry and carbon cycle.


2. Seminars: invited speakers will hold seminars on key topics of the course. At the end of each seminar an interactive activity (peer instruction) will be carried out with the aim of stimulating discussion and strengthening the understanding of the topics covered during the seminar.


3. Exercises: Individual and/or group exercises will be held in the classroom. During the exercises, practical tasks on key topics of the course will be assigned to be solved individually or in group.

Assessment methods

Assessment will be based on performance in the participation at in-class activities (seminars, exercises) and a final oral examination.

The final examination consists in a technical conversation on the course contents. In this occasion, the teacher will also ask two questions aiming at the verification of knowledge acquisition about the theoretical part of the course. The final exam will last approximately 20 minutes.

The final quotation of the Course " SOIL CHEMISTRY, AGRONOMY AND HERBACEOUS BIOMASS" will be the mean of this quotation and that obtained for the Course of "Agronomy and herbaceous Biomasses".


Teaching tools

Frontal lessons: blackboard, projector, movie, videotutorial and learning platform.

Exercises will be held in the classroom and/or in ICT laboratory: use of software for computing and graphics.

Office hours

See the website of Marco Grigatti