P-Campus Lecture Series 2023

The lecture has to be cancelled at short notice on 20.04.2023 due to illness.
New date: 27.04.2023

Abstract
Coastal ecosystems are exposed to multiple stressors due to their use and transboundary position between the sea and terrestrial realm, which can decrease ecosystem integrity and subsequent ecosystem services. For example, the catchment area of rivers transports large amounts of nitrogen and phosphorus into coastal waters, which subsequently suffer from eutrophication. Countermeasures have had limited success to date, as decreased nutrient inputs have also altered phytoplankton communities. The altered community, often consisting of picophytoplankton, is able to maintain a high biomass and turbidity despite little freely available phosphorus, which prevents the establishment of e.g. macrophytes. In this talk, ecological aspects of the phytoplankton communities of the southern Baltic Sea in relation to phosphorus will be examined in more detail. Results will be presented on seasonal, long-term, and spatial data of phosphorus, physiological, population biology and biomanipulation studies using mesocosms. It will be discussed what other management options could be pursued (or not) to reach again a clear water state in German coastal waters.

Date/Time
20.04.2023 / 15:00 - ca. 15:45 h (excl. questions)

Location
online via Webex

Lecturer
Dr. Maximilian Berthold (Phytoplankton Ecophysiology, Mount Allison University, Canada)

Language
German / slides of the presentation in English

Participation Fee
free of charge

Abstract
The availability and cycling of phosphorus in soils are significantly influenced by soil aggregates, which range in their size from large macroaggregates to smallest nanoparticles. The assembly of aggregates of different sizes creates a 3D structure with interconnected voids and pores of different shapes, sizes, and geometries. This network of pores acts as a dynamic biogeochemical interface that facilitates the movement of gases and water within the soil. The architecture and stability of soil aggregates, and thus their ability to provide niches for water storage and microbial nutrient metabolism, depend largely on the spatial arrangement of the individual structural units, their elemental composition, and the distribution of metal oxides and organic matter. In particular, soil colloids (particles smaller than 1000 nanometers) are increasingly recognized as important nutrient carriers in ecosystems because of their unique composition and large specific surface area. They are highly mobile in soils, and the transport of elements facilitated by colloids is closely linked to water movement in the soil. As a result, loss of P and other nutrients through particulate transport has become a growing concern. In this talk, we will take a closer look at the composition and stability of soil aggregates and their controls on phosphorus turnover by organisms. We will discuss the impact of land use change on the phosphorus turnover and examine analytical techniques for characterizing nanoparticles and colloids in soil, including their size and elemental composition. By means of a case study, we specifically examine subsurface transport of particulate phosphorus to adjacent surface waters. By understanding the complex interactions between soil aggregate architecture, elemental composition, and biogeochemical processes, we can control nutrient cycling in ecosystems and mitigate the loss of phosphorus and other nutrients through particulate transport.

Date/Time
01.06.2023 / 15:00 - ca. 15:45 h (excl. questions)

Location
online via Webex

Lecturer
Dr. Nina Siebers (Forschungszentrum Jülich)

Language
English

Participation Fee
free of charge

Abstract
Raman spectroscopy is an established technique for simple, non-destructive and molecule-specific analysis in many applications, e.g. the assessment of phosphate species. However, fluorescence interference can potentially mask weak Raman signals thus limiting the information content. Here, we present selected concepts to address the fluorescence issue. Confocal Raman microscopy can focus on small sample regions in the micrometer range while shielding out fluorescence from out-of-focus regions. For highly fluorescent samples, shifted excitation Raman difference spectroscopy (SERDS) can provide a suitable way to separate Raman signals from interferences using a physical approach with two slightly shifted laser wavelengths.
Detailed knowledge about soil composition is of global importance to determine fertilizer demands and to enable efficient nutrient management. Results show the spatially-resolved imaging and identification of calcium phosphates amended to three different soils. Moreover, using soil collected from an agricultural field, the identification of 13 different soil minerals and the capability for quantitative analysis, e.g. to predict the organic matter or carbonate content was demonstrated.
Molecule-specific bone analysis has implications in many areas including medicine, animal health and forensics. Measurements conducted on bone tissue (chicken thigh and pork metacarpal) demonstrate the identification of mineral (calcium phosphate) and organic (collagen) bone constituents despite strong fluorescence interference. It was shown that the mineral-to-collagen ratio is higher in chicken bone compared to pork bone thus being a suitable indicator to distinguish between these two bone types.
A portable SERDS system has been developed in-house and on-site pilot investigations on an agricultural field will be presented as application example.

Date/Time
22.06.2023 / 15:00 - ca. 15:45 h (excl. questions)

Location
online via Webex

Lecturer
Dr. Kay Sowoidnich (Ferdinand-Braun-Institut (FBH), Leibniz-Institut für Höchstfrequenztechnik)

Language
English

Participation Fee
free of charge

Abstract
The Baltic Sea is an encapsulated sea with only limited water exchange with the North Sea, but substantial riverine inflow. Those transport contaminants from agricultural and industrial uses in the catchment area. Therefore, the Baltic Sea is affected by pollution since the onset of industrialization in the late 19th century. IOW is conducting Baltic Sea long term observations on legacy pollutants; within the German EEZ on behalf of the Federal Maritime and Hydrographic Agency. The data series show continuously reducing concentrations of a number of these contaminants in the Baltic Sea. In parallel, a variety of new substances enter the Baltic Sea where they might influence marine life. Aiming the analysis of such emerging contaminants and further Baltic Sea relevant substances, method development is a continuous and substantial part of our work. In this regard and as part of our research within the PCampus, we developed methods for the analysis of two very polar compounds – the globally used broad spectrum herbicide glyphosate and the natural compound methyl phosphonate which is discussed as potential substrate for methane formation in oxic water. The interplay between the chemical properties of these substances and the saline seawater matrix hampered their analysis in seawater with common methods. Our work within the PCampus finally enabled us to report on glyphosate and methyl phosphonate concentrations for the Baltic Sea.

Date/Time
14.09.2023 / 15:00 - ca. 15:30 h (excl. questions)

Location
online via Webex

Lecturer
Dr. Marion Kanwischer (Leibniz Institute for Baltic Sea Research (IOW))

Language
English

Participation Fee
free of charge

Abstract
The P taken up by organisms cannot be synthesized from any other element. In 2014, the only source of an increasing P demand for feeding the growing global population was mineable rock phosphate, upgraded to mineral P fertiliser. Concerns about the global reserves of rock phosphates, expressed in terms of “peak phosphorus” (demand > production) alarmed the public and policy makers. Possibly, there is no other basic commodity in developed economies that compares with P in terms of vital importance and foreseeable limitations on the one hand and regional over-consumption with adverse environmental effects on the other. The European Union (EU) relies nearly exclusively on imports of phosphate rock and therefore inserted phosphate rock into the European list of critical raw materials in 2014.
Anyhow, by 2014 great achievements had been made in recycling P from wastewater, sewage sludge and other materials. In fact, a range of P recycling products had been developed and tested; e.g., ashes, chars and struvites. However, these products had been evaluated mostly by short-term laboratory, pot or plot experiments. The knowledgebase at this time was considered insufficient to overcome marked barriers for such new products. In the framework of the BMBF funded project InnoSoilPhos (2015-2024) multi-year field experiments were established evaluating the agronomic efficiency of such newly developed P fertilisers. Results of these experiments as well as from some pot experiments will be presented.
In 2016, calculations revealed that recovered P in the EU could replace about 40 % of the actually applied P fertilisers. Unfortunately, none of these newly developed fertilisers could be marketed due to national and EU wide regulations. At about the same time, a new EU Regulation (Regulation (EU) 2019/1009) was developed laying down rules on the making available on the market of EU fertilising products repealing Regulation (EC) 2003/2003. Purpose of this new regulation was to provide rules for fertilising products that will be made available CE marked on the EU market. With the newly emerging secondary P fertilisers from recycling processes it was realised that amendments to Regulation (EU) 2019/1009 would be necessary in the future. Consequently, a sub-group (STRUBIAS) of the Commission Expert Group on Fertilisers were set up to develop possible process and product criteria for struvite, biochar, and ash-based products for use in fertilising products in 2016. Between 2016-2019 detailed criteria were compiled and lead finally to the amendment of Regulation (EU) 2019/1009 with three further component material categories (CMCs) by 16th of July 2022 for precipitated phosphate salts (CMC 12), thermal oxidation materials (CMC 13), and pyrolysis and gasification materials (CMC 14). Fertilisers from these materials can now be marketed with a CE label after running through a conformity assessment procedure.

Date/Time
28.09.2023 / 15:00 - ca. 15:30 h (excl. questions)

Location
online via Webex

Lecturer
Dr. Kerstin Panten (Julius Kühn-Institut)

Language
English

Participation Fee
free of charge

Abstract
Rice serves as a fundamental dietary staple for over half of the global population. Especially in upland agricultural systems, its growth faces frequent challenges due to low phosphorus (P) availability, stemming from P-fixing soils and a scarcity of P fertilizers. Consequently, it is vital to comprehend the processes responsible for achieving high Phosphorus acquisition efficiency (PAE) to ensure sustainable crop yields in low-input farming systems. Previous research has indicated that varying PAE among upland rice varieties cannot be solely attributed to root morphological parameters (such as root system size and root hairs) or root physiology (P depletion efficiency). Therefore, we propose that biogeochemical processes occurring at the root-soil interface, known as the rhizosphere, play a pivotal role in rice PAE.
In this lecture, we will present findings related to the significance and interactions of biogeochemical processes in the rhizosphere of diverse rice genotypes exhibiting differing PAE characteristics. Our investigation involves assessing the capacity of distinct rice genotypes to acquire phosphorus from both fertilizer sources and native soil sources. Additionally, we evaluate various soil phosphorus fractions using a Hedley sequential fractionation method. To deepen our understanding of the processes underlying enhanced PAE in these rice genotypes, we conducted a separate pot experiment to analyze the quantity and composition of root exudates, with the results to be shared.
Furthermore, we will introduce a methodological innovation that enables the tracking and quantification of 33P uptake from specific root regions over time. This pioneering approach empowers future research endeavors, facilitating the quantification of 33P uptake from diverse root regions and types across varying plant growth conditions. It also aids in the assessment of the importance of different phosphorus sources for plant nutrition, ultimately advancing our models of plant phosphorus uptake from the soil.
Collectively, the results we present aim to shed light on the rhizosphere processes responsible for high P acquisition efficiency in upland rice. This knowledge will enable the integration of rhizosphere traits into breeding programs for upland rice varieties and enhance the selection of crops with exceptionally efficient phosphorus acquisition, thereby ensuring robust yields in low-input agricultural systems.

Date/Time
05.10.2023 / 15:00 - ca. 15:40 h (excl. questions)

Location
online via Webex

Lecturer
Dr. Maire Holz (Leibniz Centre for Agricultural Landscape Research (ZALF))

Language
English

Participation Fee
free of charge

Abstract
Global fish production, which includes finfish as well as invertebrates such as mollusks and crustaceans, increased substantially over the last 50 years, particularly due to the development of aquaculture. The harvest today is about 180 million tons, of which about 90 million tons are aquaculture. In particular, inland freshwater aquaculture of finfish accounts for a very large part of this, with nearly 50 million tons. Over the years, this resulted in a strong anthropogenic landward phosphorus (P) flux, which was initially positive, but which has been negative since about 2004 due to an ongoing decline in phosphorus use efficiency. Only about 20% of the supplied P is used today. Therefore, the contribution to eutrophication, among other things, is correspondingly high. By 2050, about 50% of the applied P should also be harvested. Since our research is conducted at the cellular, molecular, and genome levels, we will first seek to better understand fish P metabolism, then develop appropriate breeding approaches, and contribute to species-specific adaptation of fish diets for some of the 500 fish species currently in aquaculture. The presentation will try to bridge the gap between global P usage in fish production and molecular details of P metabolism in fish in aquaculture.

Date/Time
19.10.2023 / 15:00 - ca. 15:30 h (excl. questions)

Location
online via Webex

Lecturer
Prof. Tom Goldammer (Research Institute for Farm Animal Biology (FBN))

Language
English

Participation Fee
free of charge

Abstract
Long-distance transport of aerosol-derived nutrients is known to contribute valuable nutrients to open ocean marine ecosystems, however, our understanding of the sustained nutrient flows, essential for assessing their spatiotemporal variation and availability, remains incomplete. During transport, these particles may undergo atmospheric aging through interactions with aerosol gaseous species (e.g. NO_X, HO_x, O₃, SO_x) that may modify their surface properties and influence the bioavailability of the nutrients they carry. This study will delve into the highlights of the PHOSDMAP "Phosphorus Speciation in Mineral Dust and Marine Aerosol Particles" project that was executed in the regions of the northeastern and southeastern tropical Atlantic oceans at the CVAO (Cabo Verde) and NDAO (Namibia) respectively. The long-term phosphorus fluxes in its different forms and the impact of atmospheric processes on the aerosol derived soluble phosphorus budgets will be presented. Additionally, the effects of the nutrient deposition, including nitrate fluxes, on the local marine ecosystem in the Cabo Verde region will be highlighted.

Date/Time
16.11.2023 / 15:00 - ca. 16:00 h (excl. questions)

Location
online via Webex

Lecturer
Dr. Khanneh Wadinga Fomba (Leibniz Institute for Tropospheric Research (TROPOS))

Language
English

Participation Fee
free of charge