Direct characterization of soil P and fertilizer-soil reactions of recycling P-fertilizers by microspectroscopic methods

• Applicant: Dr. Christian Vogel
• Subject Area: Soil Sciences ; Plant Cultivation, Plant Nutrition, Agricultural Technology
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 286220554

For sustainable soil fertilization, information about the chemical state and quantities of soil phosphorus (P) is necessary. The chemical state determines the plant-availability of the P species and is a critical parameter in fertilizer efficiency. Currently, there is no single analytical method that can detect inorganic and organic P phases directly in the soil. In the proposed project microspectroscopic methods (X-ray absorption near-edge structure (XANES), deep UV Raman and infrared microspectroscopy) will be developed and optimized for correlative soil analysis. The combination of these analytical approaches will shed new light on soil P states, and will be used to investigate P-fertiliser-soil reactions. One focal point will be the analysis of novel recycling P-fertilisers and their behaviours in soil-plant systems. The project will be conducted in close collaboration with institutions such as ETH Zürich (Plant Nutrition Group), University of Gießen (Institute of Plant Nutrition), University of South Australia (Centre for Environmental Risk Assessment and Remediation) and the Institute of Agricultural and Urban Ecological Projects affiliated to Berlin Humboldt University (IASP). Agricultural pot experiments will be accompanied by these structural analysis methods. In addition, DGT (Diffusive Gradient in Thin Films) and extraction experiments will be carried out to determine the bioavailable P and immobile P in fertilisers and soil samples. Therefore, the chemical form of P will be determined directly on the DGT binding layer or the extraction residues with spectroscopic methods. The results of this extensive research will be analysed in close cooperation with the agricultural partners to explain the transformation mechanism of the P-fertiliser-soil-plant system and to enable an efficient use of P-fertilisers.

• DFG Programme: Research Grants