Chemical Nature of Nutrients and their Availability to Plants: The Case of Phosphorus
The lectures will spread over nine Friday mornings in the autumn semester. The lecture will be organized in Eschikon, in the Group of Plant Nutrition at the Experimental station Eschikon, 8315 Eschikon-Lindau. The location of the experimental station Eschikon is given at http://www.ias.ethz.ch/researchstation/eschikon.
The course will present the principles underlying the use of radioisotopes in soil/plant systems. It will present how the introduction of an isotope into a system can be done to get some information on the structure of the system. Case studies will be presented to determine element availability. Finally, published studies from other groups will be analyzed and presented by the students.
Objective
At the end of this course the students are familiar with the principles on which radioisotope works are based and they have learned from case studies how radioisotopes can be used to obtain meaningful data. They are aware of the advantages of using radioisotopes in element cycling studies, but also of the risks and open questions related to isotope work.
Content
Radio-isotopes are extensively used at the soil/plant or ecosystem level to quantify the fluxes of elements (phosphorus (P), heavy metals, radionuclides) within a given system and to assess the importance of processes controlling these fluxes (e.g. exchange reactions between the soil solution and the soil solid phase, element turnover through the microbial biomass, organic matter mineralization etc.). The course will first present the principles, the basic assumptions and the theoretical framework that underlay the work with radioisotopes. It will present how the introduction of an isotope into a system can be done so as to get information on the structure of the system (e.g. number and size of compartments). Secondly, case studies on isotopic dilution and tracer work will be presented for instance on the isotopic exchange kinetics method to determine nutrients or pollutants availability. The case studies will be adapted to the ongoing research of the group of plant nutrition and will thus give an insight into our current research. In addition, published studies will be analyzed and presented by the students. Finally, the advantages and disadvantages of work with radioisotopes will be analyzed and discussed critically.
Performance assessment as a semester course