Learning objectives
The course will introduce the student to chemical features of natural systems (freshwater, aquifer, soils and plants) in order to understand the concepts of geochemical anomalies and natural background. The knowledge of principles and methods of applied geochemistry (sampling, validation of the geochemical data, and conceptual models) will provide the student:
i) the fundamental knowledge of water, soil and plant geochemistry from an elemental and isotopic point of view;
ii) the knowledge of key geochemical technologies to study the soil formation and evolution and the interactions occurring between natural environment and food production activities;
iii) the ability in geochemical data elaboration, in order to understand the interactions between soil - plants – atmosphere systems and their relations with climate change, in the perspective of a sustainable agriculture and of countering the ongoing climate crisis.
iv) The knowledge of near infrared spectroscopy (NIRS), microraman, high-performance liquid chromatography (HPLC), elemental analysis (EA) isotope ratio mass spectrometry (IRMS), ion cromatography (IC), Kjeldahl digestion and inductively coupled plasma-mass spectrometry (ICP-MS) and other techniques to detect the elemental and isotopic fingerprints in order to investigate food origin and its authenticity.
The course will also allow the students to have a new, modern vision on agro-food geochemistry in relation to territory, to the bio-geochemical cycles and to the human impacts. It will also deals with the application of environmental isotopes (13C, 2H, 37Cl, 15N, 18O, 34S and 11B) for tracing studies on:
- freshwater and groundwater pollution from agricultural sources and human activities;
- influence of C3 and C4 plants, soil texture, seasonal changes and soil microbial communities on the assimilation and cycling of Carbon and Nitrogen.
The topics comprise the geochemical analyses of soil–atmosphere carbon exchanges and the isotopic balance of the soil organic matter stocks to quantify the perturbations due to climate or land use changes.
The class will be a path of knowledge starting from the Biosphere (intended as the ensemble of the life-hosting areas of the Earth: the upper part of the lithosphere, the hydrosphere and the first strata of the atmosphere) and its dynamics, passing through the various human agro-food production activities and ending with the bearings (interactions, modifications and adverse effects) that these activities have on the Biosphere itself. The student will learn practices, means and strategies to reduce the impacts of agriculture as well as the analytical methods and data processing applicable to hydro-agro-food materials.
The student will also learn the principles of food security and production protection (with focus on territoriality and traceability of agro-food products) and the relationships between soil, climate, agricultural practices and geochemical “footprint” of the various cultivars.
Great emphasis will be given to the knowledge of causes and effects of the climate change, in particular the contribution of the agro-food sector in the GHG emissions, with the aim of interpreting the on-going climate emergency and stimulating the finding of innovative and effective solutions to one of the biggest challenges for the modern society.
Prerequisites
The knowledge of fundamental concepts of chemistry, geology and biochemistry at secondary school level are required. No prerequisites are needed.
Course unit content
- Introduction. Principles and methods of applied geochemistry.
- Basic knowledge of rocks composition, their alteration due to weathering and hydrolysis processes.
- Bio-geochemical cycles of the elements and their anthropogenic modifications.
- Genesis and physical characteristics of soils; geochemical and petrographic features of soil at different observation scales.
- Trace elements and their mobility in low P_T conditions.
- Geochemistry of circulating solutions; interactions between environment factors, temperature, humidity and climate.
- Basic knowledge of rock and sediment chemical composition in relation to water, soil and plants bio-geochemistry.
- Water-gas-rock- plants interactions.
- Bio-geochemical features and soil biodiversity: microfauna, mesofauna, macrofauna and their role in the soil ecosystem.
- Geochemistry of radioactive isotopes.
- Application of radioactive isotopes to geographical authentication of food.
- Stable isotopes geochemistry and isotope fractionation.
- Carbon cycle; mentions on soil organic matter formation and dynamics.
- Geochemistry of soil–atmosphere carbon exchanges and isotopic balance of the soil organic matter stocks.
- Fractionation of carbon isotopes in oxygenic photosynthesis: C3, C4 and CAM plants.
- Nitrogen cycle; methods to measure N species in soils and to quantify N transformation rates.
- Other stable isotopes and their applications to characterize the soil habitat (2H, 37Cl, 18O, 34S).
- Application of stable isotope geochemistry to hydro-agro-food systems and geographical authentication of food.
- Geochemistry of the water cycle and its contaminations.
- Phosphorus cycle.
- Application of geochemical prospecting to environmental issues (soil contamination; composition of the atmosphere and its short and long term variations; impacts of agricultural practices on the environment).
- Organic and inorganic conditioners to improve the properties of soil and cultivation substrata. Use of minerals with exchange capacity (natural zeolites) as agricultural soil conditioners, their effects on the water/air/soil system. Examples of good practices involving natural zeolites application (ZeoLIFE and ZEOLIVA projects).
- Natural zeolites for agri-food effluents treatment: adsorption isotherms, adsorption models and their interpretations.
- Traceability of agro-food products, geochemical characterization of cultivars. Soil-plant assimilation, territorial geochemical and isotopic markers and their variation in correlation to climatic conditions and rainfall regimes.
Full programme
The class is divided into 24 lessons of 2 hours, for a total of 48 hours:
- Introduction. Principles and methods of applied geochemistry.
- Basic knowledge of rocks composition, their alteration due to weathering and hydrolysis processes.
- Bio-geochemical cycles of the elements and their anthropogenic modifications.
- Genesis and physical characteristics of soils; geochemical and petrographic features of soil at different observation scales.
- Trace elements and their mobility in low P_T conditions.
- Geochemistry of circulating solutions; interactions between environment factors, temperature, humidity and climate.
- Basic knowledge of rock and sediment chemical composition in relation to water, soil and plants bio-geochemistry.
- Water-gas-rock- plants interactions.
- Bio-geochemical features and soil biodiversity: microfauna, mesofauna, macrofauna and their role in the soil ecosystem.
- Geochemistry of radioactive isotopes.
- Application of radioactive isotopes to geographical authentication of food.
- Stable isotopes geochemistry and isotope fractionation.
- Carbon cycle; mentions on soil organic matter formation and dynamics.
- Geochemistry of soil–atmosphere carbon exchanges and isotopic balance of the soil organic matter stocks.
- Fractionation of carbon isotopes in oxygenic photosynthesis: C3, C4 and CAM plants.
- Nitrogen cycle; methods to measure N species in soils and to quantify N transformation rates.
- Other stable isotopes and their applications to characterize the soil habitat (2H, 37Cl, 18O, 34S).
- Application of stable isotope geochemistry to hydro-agro-food systems and geographical authentication of food.
- Geochemistry of the water cycle and its contaminations.
- Phosphorus cycle.
- Application of geochemical prospecting to environmental issues (soil contamination; composition of the atmosphere and its short and long term variations; impacts of agricultural practices on the environment).
- Organic and inorganic conditioners to improve the properties of soil and cultivation substrata. Use of minerals with exchange capacity (natural zeolites) as agricultural soil conditioners, their effects on the water/air/soil system. Examples of good practices involving natural zeolites application (ZeoLIFE and ZEOLIVA projects).
- Natural zeolites for agri-food effluents treatment: adsorption isotherms, adsorption models and their interpretations.
- Traceability of agro-food products, geochemical characterization of cultivars. Soil-plant assimilation, territorial geochemical and isotopic markers and their variation in correlation to climatic conditions and rainfall regimes.
OPTIONAL: Practical exercises on sampling techniques for rocks, soils, interstitial waters and gaseous emissions from soils. Chemical analyses of hydro-agro-food materials. Lab analyses of some physical-chemical parameters of the samples. Database creation, data processing and elaboration. Introduction to statistical analyses (parametric and non-parametric tests, ANOVA, Kruskal-Wallis, Tukey and Fisher multiple comparison tests, correlation matrixes).
Bibliography
The student will be provided of the slides used during the course (in pdf format), of scientific papers and of audio-video files; all materials and links will be put in the teacher website.
Recommended texts are:
- Faure G., 1998. "Principles and Applications of Geochemistry", 2nd ed., Prentice Hall.
- Dazzi C., 2003. “Fondamenti di Pedologia”, Edizioni Le Penseur.
Teaching methods
The course is divided into a series of classroom lessons and may eventually include a series of practical exercises both in open-field, in lab and with the use of softwares.
Classroom lessons will be carried out using video presentations, always updated, that will be provided to the students at the end of each teaching module. The students unable to attend the lessons in presence will follow them in streaming (by videoconference).
Assessment methods and criteria
The final exam will consist in an oral examination, of about 30 minutes, aimed to evaluate the knowledge level of the student on theoretical and methodological contents.
Other information
Attendance is not mandatory but it's strongly recommended
