Innovative solutions to sustainable Soil Phosphorus management

, Universität BonnProject number: 031B0509A
Contact: Prof. Dr. Peter Leinweber, University of Rostock
Mail: peter.leinweber@uni-rostock.de
Project team: University of Rostock, Julius-Kühn-Institute, Technische Universität München, Brandenburgische Technische Universität Cottbus, Forschungszentrum Jülich, Bergische Universität Wuppertal (BUW), University Bonn
Link Website: www.innosoilphos.de
Duration: 01/03/2018 – 28/02/2021

Project aim 
InnoSoilPhos intents to optimize the soil-P-fertility in order to lower the dependency on phosphate rock-derived P-fertilizers. The P use efficiency in the soil-plant-water-system will be improved by developing new technologies and pro­ducts. Furthermore, the socio-economic and political/legal frame­work will be developed. 
Motivation 
Phosphorus (P) is essential for all life on earth and soils are central in providing P to microorganisms and agricultural crops. While todays agriculture depends on external inputs of non-renewable mineral P fertilizers, a long-term bioeconomy strategy requires to lower the dependency on finite, rock-phosphate derived P fertilizers. A more efficient use of P in crop production is also essential for conserving or improving the freshwater quality. The research is directed to a better understanding of the P transformations across all scales from the atomic and molecular through plot/field/catchment up to the societal scale. The investigations utilize the great potential of novel physical (e.g. quantum-chemical modelling, synchrotron-based spectroscopy), chemical and micro- & molecular-biological methods. 
Expected results 

New evidence in all aspects of P-speciation and P–transformations in the system soil-crops-environment will result in improved P-fertilizer recommendations, approaches to mobilize unavailable P-stocks in subsoils, application guidelines for innovative P-recycling products, novel concepts for “smart” P-fertilizers with by-effects as well as recommendations for policy makers. InnoSoilPhos will provide the BonaRes-center with all P-specific soil data, pedotransfer functions and concepts for web-based soil-function-models. 

 

Project results from phase 1

 

Quantum-chemical modelling revealed the binding energy of phosphate and organic P-compounds (e.g. glyphosate) on reactive soil surfaces. Enzymatic and molecular-biological investigations on rhizosphere showed mechanism of P-mobilization under the influence of different management strategies. Data analysis of long-term field experiment resulted in crop-specific phosphorus supply as well as fertilizer policy. Improved and decreased P fertility classes were derived from data sets, which could lead to saving potentials in fertilizer application. Reduction of P-losses in waters necessitate the control of peak discharges in drained areas. P return of bones by means of pyrolysis and interim use of bone char as absorber material is targeting the conservation of geogenic P resources by recycling. P management derived by the project can be improved due to regulatory and economic control instruments.

 

Expected results from phase 2

 

In phase 2 we complete the quan­tum-­chemical modelling of the most important P-binding mecha­nisms in soil including surface modifications by organic matter. Soil biological/­micro­biological investigations will result in better understanding of rhi­zo­­sphere P-mobilization, especially if initiated by intercrops. Novel field experiments will establish diagnostic criterial for P starvation in crops and the effects of P recycling products. Furthermore, the P transformations under the influence of varying redox potentials will be studied at different scales. Meta data evaluations will result in improved P-fertilizer recommendations compiled as computer application. The P-fertilization patterns at farm scale in typical agricultural regions in Northern Germany will be disclosed and serve as a basis for economic evaluations and governance options.