Healthy soils containing sufficient mineral nutrition for plants are the basis for our natural ecosystems and food production. Nevertheless, a great proportion of our European soils are subjected to erosion and are infertile. For a better management, we need to better understand the mechanistic processes happening in soils at a nanoscale. Symbiotic arbuscular mycorrhizal fungi (AMF) are important for both soil aggregate built-up via their extensive hyphal network and protein production; and supply their host plants with nutrients, especially phosphorus (P). I will study the dynamics of soil aggregation with a rare earth element labelling approach, and the protein structure of AMF derived soil macroaggregates with the help of synchrotron radiation based microscopy. AMF produce a protein called glomalin which is highly correlated with soil stability, but we do not know the microscale role of this protein in soil aggregation yet. Concerning a sustainable P nutrition of plants, I will examine the role of AMF in acquisition of P from minerals and biochar. For this, I will apply Fourier-transformed infrared microscopy, with which I will measure removal of phosphate out of a thin surface layer on the Goethite and biochar. Concluding, I will evaluate possible consequences for soil management and soil ecosystem functioning.