Nutrient Communities for Sustainable Agriculture - Project at ISWA

The collaborative project RUN (Rural Urban Nutrient Partnership) has started its work. Coordinated by the Institute for Sanitary Engineering, Water Quality and Solid Waste Management (ISWA) of the faculty, scientists from various disciplines are developing system solutions together with practical partners with the aim of closing nutrient cycles between urban and rural areas.

The world needs the efficient use of resources. Agriculture, too, must break new ground in resource-conserving food production. This applies not only to agricultural methods of production and management, but also to changes in the consumer behaviour of urban residents and innovative recycling methods for biowaste and domestic wastewater. In the RUN project, researchers, together with two industrial partners and an associated practical partner, are developing a concept for closing the cycle through nutrient communities between urban residents and farmers. RUN is one of eight projects of the research project "Agricultural Systems of the Future" within the framework of the "National Research Strategy Bioeconomy 2030". The Federal Ministry of Education and Research (BMBF) is supporting the three-year project with a good 4.2 million euros.

Real Laboratory - Socio-technical Experiment under Real-Time Conditions

The structure of the project partly resembles a real laboratory, a pilot plant and an experience room are to be set up. There, the new technologies can be tested under real-time conditions and with the participation of real actors. Project coordinator Prof. Martin Kranert from the Chair of Waste Management and Emissions at ISWA: "RUN links technologies, material flow models, systemic scenario analysis and social science participatory methods".

Recycling products and their environmental impact under the magnifying glass

In a sub-module, the project members develop concepts and technologies to develop nutrients from bio-waste and domestic wastewater into a safe and effective design fertilizer for agriculture. It is planned to build a large-scale pilot plant in an urban residential area in Heidelberg to demonstrate the implementation of nutrient recycling from the city into agriculture in a short cycle. Future recycled products must ensure safe use. Methods of recovery will therefore be tested in laboratory experiments, nutrient balances calculated and products such as fertilizers, biogas (for energy generation), thermally produced vegetable charcoal and bioplastics produced. In addition, the nutrient availability of the fertilizers produced for plants will be investigated and their usability in agriculture assessed. With the help of life cycle assessments, RUN partners assess the environmental impact of the new technologies in parallel. The development and investigation of the new technologies are being carried out by the water and waste management experts from the University of Stuttgart (ISWA), as well as scientists from the Technical University of Kaiserslautern, the University of Hohenheim and the Thünen Institute in Braunschweig. Further project partners are the engineering offices Björnsen Beratende Ingenieure GmbH and iat-Ingenieurberatung für Abwassertechnik GmbH.

Modeling the use of fertilizers at a specific location

The task of a further partial module is a systemic analysis for the use of new technologies and concepts. Scientists from the Institutes of Farm Management and Crop Plant Sciences at the University of Hohenheim and the Thünen Institute (TI-AT) will initially assess the profitability of possible concepts, draw up life cycle assessments to identify conflicts of objectives and model regional nutrient management. Using scenario analyses, employees of the Institute for Landscape Planning and Ecology (ILPÖ) at the University of Stuttgart, the ISWA and the KIT Institute for Technology Assessment and Systems Analysis also produce models that depict favoured areas as well as the effects on local infrastructure, the economy and the environment. The scenario analyses will culminate in a system model that holistically shows the type and quantities of the expected material flows. With the help of the system model, the researchers assess whether there are conflicts of use or objectives between the actors, for example. This also makes it possible to examine transfer possibilities to other regions.

Using user perspectives for the best possible design of cycles

A third module is dedicated to possible needs, requirements, experiences or obstacles to the recycling of waste and wastewater in agriculture from the users' point of view. Scientists from the University of Heidelberg and the KIT research traditions of thought and behaviour as well as relevant previous experience with similar projects at other locations, organise focus groups, conduct surveys and derive factors from these that influence the psychosocial handling of the collection, treatment and recycling of waste among the central user groups "farmers" and "urban residents". Through the empirical studies, the researchers want to identify possible reservations of urban dwellers about changed user interfaces (e.g. in the form of vacuum toilets) and learn more about farmers' preferences for fertilisers. The sociologists from Heidelberg are working together with Hohenheim agricultural economists to find out how design fertilisers must be designed from their point of view and under what logistical and business conditions they find buyers. The findings are incorporated at an early stage into the development of concepts, spatial scenarios and the design of the pilot plant, including the space for experience. The experience space will make all steps in nutrient recycling visible, from the production of nutrients in households to their return to agricultural production.
Integration and communication of the results

Guarantee integration and communication of results

In the core module, the RUN partners combine the results and develop sustainability criteria in close cooperation with the submodules and stakeholders. They then evaluate the developed solutions on the basis of the previously determined data. The aim is to ensure the sustainability of the nutrient communities. The Research Centre for Global Food Security and Ecosystems at the University of Hohenheim supports the exchange of results within the scientific community, improves the information and decision-making basis for decision-makers and sensitises the population to nutrient cycles between urban and rural areas. It is important, for example, that urban residents see themselves not only as consumers, but also as producers of valuable secondary nutrients. By thinking all components together, RUN serves as a beacon project. This enables researchers to check whether the recycling and utilisation concepts can also be transferred to other larger regions such as the Rhine-Neckar metropolitan region.