Project Details
Projekt
Towards a Molecular Level Understanding of Phosphorous-cycling in Forest Ecosystems
Applicants
Dr. Ashour Ahmed, Ph.D.; Professor Dr. Oliver Kühn
Subject Area
Soil Sciences
Term
from 2016 to 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 320387705
Facing the projected peak phosphorus (P) scenario, novel P research platforms have been established and substantial research activities have been triggered to improve the knowledge towards a more efficient and sustainable use of P resources. The SPP 1685 priority program has its focus on processes controlling P acquisition and P cycling for the forest ecosystems. The present project extends the efforts of the SPP consortium by investigating P-sorption/desorption processes at the molecular level using methods from Computational Chemistry. Whereas the experimental works are directed to find out which components are abundant in the different study areas, and which reactions may be prevalent, computational chemistry and quantum chemical modeling have the potential to better explain the experimental findings. Our goal is to unravel the basic mechanisms and influencing factors of P-binding. Specifically, molecular models mimicking P-processes in forest soils will be developed and cast into a numerical simulation protocol. Thereby, we will build on and extend our previous work on soil from agro-ecosystems. In cooperation with experimental partners within the SPP and at the University of Rostock the following questions will be addressed: (i) What are the binding motifs and energies of organic and inorganic phosphates at reactive soil mineral surfaces? How this binding is influenced by environmental conditions such as the pH value? (ii) For a given phosphate specie, how does its binding to a mineral surface depend on the properties of that surface, e.g. the alkaline Ca-containing vs. acidic Al- and/or Fe-oxide character found at the different central field sites of the SPP? (iii) What is influence of mineral surface coverage with organic material, typical for forest soil, i.e. resulting from the dissolved organic matter or deriving from microbial activity? (iv) How does the binding to mineral surfaces compare with the binding to reactive surfaces of nanometer-sized macromolecular soil organic matter particles?
DFG Programme
Priority Programmes
