Phosphorus solubilization by microorganisms and plants at different stages of soil development

Investigator Names and Contact Info:

• Marie Spohn (Soil Ecology). University of Bayreuth, Department of Soil Ecology, Germany

Chilean Collaborators Involved:

• Felipe A. Aburto. (Pedology, Biogeochemistry). Facultad de Ciencias Forestales, Universidad de Concepción, Chile

Soil ecological and soil chemical study of phosphorus solubilization by microorganisms and plants at different stages of soil development.

PhD-Student:

• Emanuel Brucker. University of Bayreuth, Germany

Supervisor: Dr. Marie Spohn

Phosphorus solubilization in the rhizosphere in soils of the Chilean Coastal Cordillera.

BSc-Student:

• Isabell Zeißig. University of Bayreuth, Germany

Supervisor: Dr. Marie Spohn

Project Summary:

Phosphorus (P) solubilization in soils is a crucial process for ecosystem nutrition and ecosystem development. Previous research on biogenic P solubilization focused on single microbial strains, but little is known about P solubilization as a process of soil formation and ecosystem development. The general objective of the project is to gain understanding on how microbial and plant mediated P solubilization and silicate weathering influence the formation of soil and its P forms. For this purpose, we will quantify the rates of P solubilization and of silicate weathering in a sequence of soils on granites of different stages of development in the coastal range of Chile. We aim at determining mechanisms of microbial P solubilization such as the release of protons and organic acid anions, the factors controlling P solubilization, and the abundance of P-solubilizing bacteria at different stages of soil development. The rates of P solubilization and silicate weathering will be related to soil P fractions (Hedley fractions) that have formed during pedogenesis. We will test the hypothesis that mechanisms, rates, controlling factors and abundances of P-solubilizing bacteria strongly change during soil development. The main value of the project will be that it relates microbial P solubilization taking place at a time scale of several weeks to the development of soils and P fractions taking place over hundreds of years.