31278 - Soil Fertility Management

Learning outcomes

By the end of the course, students will have acquired knowledge of soil structure and properties and of the main biochemical and chemical processes governing soil fertility. They will be able to independently apply the conceptual and technical tools required for the study and analysis of soil and its physicochemical and biochemical properties, with particular reference to viticultural pedoclimatic conditions.

Course contents

A) Prerequisites

Students enrolling in this course are strongly advised to have a solid background in the fundamentals of mathematics, physics, chemistry, plant biology, and agricultural microbiology. These prerequisites are provided by the basic courses delivered during the first year of the degree programme.

B) Teaching Units

The course is divided into two teaching units.

Unit 1 – Soil Chemistry (Total: 18 hours)

1.1 Soil formation and evolution

Pedogenesis: chemical, physical, and biological processes, and the factors governing soil formation and evolution.

Classification: the soil profile and diagnostic horizons; basic principles of soil classification.

1.2 Soil phases

Mineral solid phase: silicates and phyllosilicates, allophanes, oxides and hydroxides, carbonates.

Organic solid phase: organic matter. Mineralization and stabilization. Structure, properties, and functions. Characterization of soil organic matter. Soil organisms: composition and functions. Soil enzymes: composition, properties, and functions. The rhizosphere: composition, properties, and functions. Organic matter: composition, physicochemical properties, dynamics, and agronomic functions.

Liquid phase: composition, matric potential, water retention, and movement.

Gaseous phase: composition of soil air and gas exchange.

1.3 Physicochemical properties of soil

Physical properties: texture, structure, bulk density, and porosity. Aspects related to soil erosion, with particular reference to vineyard systems.

Chemical properties: specific surface area of soil particles, origin of surface charges, cation and anion adsorption and exchange, exchange models, thickness and potential of the electrical double layer, exchangeable bases, characteristics of ion exchange, affinity, lyotropic series, exchange equations, dilution effects. Anion adsorption and exchange: soil anions and specific adsorption. Specific adsorption of phosphates, dissolution and precipitation mechanisms. Soil reaction: pH and its measurement, actual and potential acidity, soil classification according to pH, relationships between pH and plant nutrients, pH and soil biological activity, major buffering systems and mechanisms regulating soil pH. Basic concepts of statistics applied to the physicochemical composition of soil.

1.4 Anomalous soils

Acid soils: formation, physicochemical characteristics, and corrective measures.

Saline soils: formation, physicochemical characteristics, and corrective measures.

Sodic soils: formation, physicochemical characteristics, and corrective measures.

Knowledge acquired in Unit 1

The student:

• understands the processes of soil formation, the structure of its main constituents, and the principal physicochemical characteristics of the mineral and organic phases;
• understands the main properties of the liquid and gaseous phases;
• understands the parameters defining the principal physical properties of soil and their relationships with chemical properties;
• understands the processes and theories governing exchange phenomena on the surfaces of the solid phase and their relationships with soil fertility, the mechanisms determining soil reaction and buffering systems, the relationships between soil reaction and fertility, as well as the characteristics and corrective techniques for problematic soils;
• understands the roles and functions of living organisms in soil, the functional and ecological roles of extracellular soil enzymes, the processes leading to rhizosphere formation, and the main aspects of rhizosphere functionality.

Unit 2 – Soil Fertility (Total: 18 hours)

2.1 Mineral nutrition of plants

Introduction to plant nutrition. Absorbed, essential, and toxic elements. Mobility of elements in soil: mass flow, diffusion, and root interception. Uptake, metabolism, and biochemical functions of nutrients in plants. Nutrient transport systems: passive transport, primary active transport, and secondary active transport. The rhizosphere.

2.2 Nutrient cycling in soil

Nitrogen, phosphorus, potassium, sulfur, secondary macronutrients (Na, Ca, Mg), and micronutrients (B, Co, Cu, Fe, Mn, Mo, Zn). Mineral nutrition and productive/physiological responses. Ionic equilibria in soil. Liquid phase. Solubility of mineral phases: the role of pH and redox conditions. Metal complexation reactions: stability constants. Chemical soil analysis for determining the plant-available fraction of nutrients. The rhizosphere: root exudates and biological activity. Root iron uptake: Strategy I and Strategy II. Soil fertility assessment.

2.3 Fertilizers and related legislation

Fertilizers. Italian legislation (Legislative Decree No. 75/2010) and European legislation (EC Regulation No. 2003/2003). Organic farming (EC Regulation No. 889/2008) and low environmental impact agriculture. Use of municipal and agro-industrial biomasses as fertilizers.

Competencies acquired in Unit 2

The student:

• understands the essential and toxic elements involved in plant nutrition, with in-depth knowledge of their uptake and biochemical functions;
• understands the nutrient cycles within the soil system and their importance in determining crop productivity;
• understands the principles and practices of soil fertility management;
• understands the main national and European regulations governing fertilizers.

Unit 3 – Cooperative Learning and Final Assignment (Total: 24 hours)

At the end of each teaching unit, an informal assessment of the acquired knowledge will be carried out, with the opportunity to review topics that may have remained unclear. At the same time, volunteer students will be given the opportunity to explain one of the unit topics to the class. An outstanding performance by a volunteer student will be rewarded during the final examination.

At the end of both teaching units, students will be offered the opportunity to prepare a short group assignment (maximum four students per group). Particularly high-quality work will be rewarded during the final examination.

Readings/Bibliography

Mengel K. and Kirkby E.A. (2001). Principles of Plant Nutrition. 5th Edition. Pages 849. Kluwer Academic Publishers, Dordrecht, Boston, London.

Teaching methods

Lessons, Units 1 and 2: Through classroom delivery of the teaching units, students acquire the knowledge necessary to understand the chemical, biochemical, and microbiological processes underlying the functioning of the soil–plant (grapevine) system. The acquisition of knowledge and the development of understanding will be continuously monitored throughout the lectures by means of ongoing interaction between the instructor and the students.

Cooperative lessons and workgroup, Unit 3:

• At the end of each teaching unit, students will complete an anonymous survey indicating the topics they understood best and those they found most challenging. Beginning with the following class session, students will have the opportunity to explain to the class a topic that was not fully understood. The instructor will intervene, where appropriate, to supplement or clarify the explanation.
• Groups of students will have the opportunity to prepare an optional group assignment, choosing one of the following:
  1. Interview with a professional oenologist or viticulturist on the effects of fertilization on vineyard management and wine quality, including the collection of professional experiences and anecdotes; or
  2. Winery visit report, in which at least three students visit wineries producing wine from the same grape variety but grown under markedly different soil conditions. (At least one student in the group must serve as the designated driver.)

Assessment methods

Learning is assessed exclusively through a final oral examination, which evaluates the acquisition of the expected knowledge and skills by means of an interview lasting approximately 30 minutes. During the examination, students' learning outcomes will be assessed. As a rule, students will be asked three questions covering the topics addressed during lectures and practical sessions.

With regard to assessment, the use of artificial intelligence (AI) is strictly prohibited. Any use of AI constitutes a violation of academic integrity.

To take the examination, students must register through the online examination booking system within the prescribed deadlines. Students who are unable to register by the deadline are required to notify the instructor promptly, and in any case before the registration lists are closed.

Teaching tools

Overheads projector, Video projector, PC, Slides projector

Office hours

See the website of Enrico Buscaroli