Microbial functions in soil nutrient dynamics
Plant Nutrition
A good understanding of biological cycling of P in terrestrial ecosystems is important in view of both decreasing mineable P reserves and eutrophication with P.
To study biologically mediated P cycling in soils poses analytical problems due to P sorption, buffering processes and indirect determination of organic P by wet chemistry. In my work, I am often combining different analytical techniques. For example, the importance of soil P uptake by microorganisms following substrate additions was shown by a combination of radioisotope techniques with chemical and biochemical methods. Two approaches of measuring gross organic P mineralization and microbial P uptake were combined to derive net organic P mineralization rates. Studies in a long-term field experiment suggested a close linkage between carbon and organic P dynamics and a relationship between microbial community composition and forms of organic P characterized by solution 31P NMR.
We are currently developing enzyme additions as a tool to assess the bioavailability of organically bound P. In addition, I am starting to work on molecular tools to quantify the role of microorganisms in soil P cycling and to identify the main actors.
Research topics
Mineralization and immobilization of phosphorus in soils
Characterization and bioavailability of soil organic phosphorus
Role of bacteria and fungi in soil phosphorus dynamics
Enzymatic processes and diversity of functional genes in soil phosphorus dynamics
Soil phosphorus dynamics under drying-rewetting conditions
Interdisciplinary
Plant phosphorus acquisition strategies
Phosphorus cycling and climate change
Soil fauna, microbes and phosphorus dynamics in the rhizosphere
