212-306 Processes in the Soil Environment

Credit Points

Coordinator

Prerequisites

212-201 Soil Resources

Semester

Contact

Subject Description

By the completion of the subject, students should have developed an appreciation of the dynamic nature of the soil resource; have acquired detailed knowledge of chemical, physical and biological processes in the soil environment, particularly those which impact directly on plant growth; and have gained an understanding of how soils can be managed to optimise plant growth and minimise adverse effects on the environment.

Topics to be covered include:

Soil-plant relationships - Concepts in plant nutrition, mechanisms of nutrient uptake by roots, nutrient interactions; the rhizosphere, diffusion and mass flow, redox, carbon and nutrient dynamics; soil as a medium for plant growth, processes controlling nutrient availability with particular reference to nitrogen, phosphorus, potassium, sulphur and the micro-nutrients; assessment of nutrient availability including quantity/intensity relationships; processes of soil acidification and amelioration of soil acidity.

Soil contamination - Contaminants in urban and agricultural systems, reactions and mobility in soil, soil remediation.

Soil biotechnology - Symbionts and their role in plant nutrition, microbially-derived plant growth regulators, inoculation, soil enzymes and biological inhibitors.

Soil physical processes - Soil structure classification and effects on water and solute movement, leaching and model descriptions of solute transport.

Assessment

Up to three hours of written examination. Tests on the practical component of the subject may be given during the semester. Marks will also be allotted for assignments and practical reports. The weighting of each component will be published at the beginning of the semester.

Prescribed Texts

• White, R E, Principles and Practice of Soil Science. Blackwell Science, Oxford (3rd ed), 1997.