88374 - SOIL CHEMISTRY AND CARBON CYCLE

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

The Course contents are divided into two subunits: one dealing with general concepts related to soil as a biosystem and the other one related to the evaluation of case studies

1. General concepts (25 hours)

1.1 Soil Chemistry (7 hours)

Soil components. Chemical and physical characteristics of the soil finest fraction: clay minerals, oxy-hydroxides components and humic substances. Cementing agents.

1.2. The biogeochemical carbon cycle (6 hours)

Sources of soil organic matter. Composition of plant residues. Decomposition of organic matter. Humic substances: genesis, nature and colloidal characteristics. The biogeochemical nitrogen cycle. Carbon/nitrogen ratio. Factors affecting soil organic matter and nitrogen.

1.3. Strategies to increase C sink (6 hours)

Recycling of agricultural, forest, agro-industrial and urban biomasses. Animal manures: significance, quantity, chemical composition, storage , treatment, management, long-term effects on soil. Urban and industrial wastes. Sewage effluent and sludge. Composts

1.4. Soil as a biofilter against pollution (6 hours)

Behavior of (in)organic pollutants in the soil-water-plant biosystem according to their chemical-physical characteristics. Adsorption and (a)biotic transformations of pollutants at rhizosphere level. Root accumulation at the root and plant uptake.

2. Case studies (17 hours)

2.0 Carbon cycle (5 hours)

2.1 Modelling soil carbon and nitrogen cycles during land use change (6 hours)

2.2 Erosion, deposition and soil carbon: Process-level controls, experimental tools and models to address C cycling in dynamic landscapes (6 hours)

Readings/Bibliography

Handouts

Text Book: The Nature and Properties of Soils (Ray R. Weil and Nyle C. Brady) 15th edition (Chapters 8th, 12th, 13th, 16th, 17th and 18th)

Recent Reviews on global carbon cycle

Teaching methods

During the classroom teaching activities, the students will acquire the main concepts on soil chemistry, how to preserve the carbon sink and how to limit soil pollution introduced by amendment activities.

The knowledge acquisition and the comprehension of students will be monitored along the entire teaching period through a continuous interactions between the teacher and students through a problem solving approach.

The teacher-student and student-student interactions are also finalized to improve the development of the evaluation skills and to increase the communication ability of the students. For this reason, students in small groups (2-3 people possibly with different formation background) will be asked to work together to produce a report on global carbon cycle and carbon sink. The report presentation will furnish an excellent occasion to publicly discuss and deepen the Course contents.

Assessment methods

Oral examination with positive marks from 18/30 to 30/30L. 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 "Herbaceous Biomasses"

Teaching tools

Blackboard, Projector, Handouts, slides, Periodic Table of the Element, scientific websites

Office hours

See the website of Ilaria Braschi