Institute of Fluid-Flow Machinery
Polish Academy of Sciences

CiNURGi

CiNURGi - Circular nutrients for a sustainable Baltic Sea Region

Programme: Interreg Baltic Sea Region 2021 - 2027

Total budget: 6 537 861,04 €

ERDF funding: 400 300,99 €

Project website: https://interreg-baltic.eu/project/cinurgi/

The CiNURGi project, implemented between 2023 and 2026, has fostered a symbiosis between enterprises, enabling the conversion of nutrient-rich biomass—sourced from agricultural, municipal, and industrial origins—into safe fertilizers. Furthermore, the project has provided public authorities with strategies to facilitate the further reduction of nutrient losses in the future.

THE ROLE OF IMP-PAN

SUPPORT CENTRES FOR NUTRIENT RECOVERY TECHNOLOGIES

As part of the project, support centres were established—coordinated by the Institute of Fluid-Flow Machinery of the Polish Academy of Sciences (IMP PAN), RISE (Research Institutes of Sweden), and LUKE (Natural Resources Institute Finland)—in collaboration with industrial partners such as SF-Soepenberg GmbH (Germany), Green Circle (Lithuania), and VA SYD (Sweden). The project partners assisted various enterprises—including water and wastewater utilities, waste management entities, biogas plants, and small and medium-sized enterprises (SMEs)—in testing diverse fertilizer production methods, encompassing mechanical, thermal, and chemical processing of various feedstocks. This exchange of knowledge and resources created a vital feedback mechanism between experts and target groups, supporting the objective of scaling up nutrient recovery processes. These concepts are outlined in a report titled: "Circular Nutrients for a Sustainable Baltic Sea Region: Piloting nutrient recovery (NR) through knowledge and processing support centres to produce recycled nutrient fertilizers (RNF)." Drawing on experience gained from collaborating with various economic entities, the project partners have developed a collection of case studies—the *Case Studies Report*—which showcases practical, operational technologies for producing fertilizers from recovered nutrients, as well as the business models applied in this field. This report complements previous studies by presenting mature technological solutions categorized by sector: agricultural, industrial, and municipal. The document illustrates diverse methods for transforming biomass—sourced from agriculture, municipal waste management, and industry—into fertilizers containing recovered nutrients. Although these technologies vary in terms of maturity, chemical composition, regulatory status, and market readiness, they collectively demonstrate that RNF-type fertilizers hold immense potential for supporting circular economy systems in the realm of nutrient management.

ASSESSING THE AGRONOMIC EFFICIENCY OF CIRCULAR FERTILIZERS THROUGH GREENHOUSE TRIALS

Agronomic efficiency reflects a fertilizer's effectiveness in terms of plant growth and crop yields. A common criticism of fertilizers derived from recovered nutrients—referred to as "recycled nutrient fertilizers" (RNFs)—is that they are less effective than mineral fertilizers. Consequently, evaluating the agronomic efficiency of various types of RNFs is a key component of the work undertaken within the CiNURGi project. Six project partners—METK (Estonia), the Institute of Fluid-Flow Machinery of the Polish Academy of Sciences (IMP-PAN), the Julius Kühn Institute (JKI), the Natural Resources Institute Finland (LUKE), Linnaeus University (LU), and the Swedish University of Agricultural Sciences (SLU)—conducted soil incubation studies and greenhouse pot experiments to assess the agronomic value of different RNFs. The incubation experiments provided insights into how nutrients are released from RNFs into the soil, as well as the stability of the carbon they contain. Meanwhile, the pot experiments made it possible to examine the impact of these fertilizers on plant growth, crop yields, and nutrient uptake. The greenhouse studies also served to verify and supplement the findings from the incubation experiments, enabling the calculation of a phosphorus use efficiency index for the RNFs. To standardize the research and ensure the comparability of results, the CiNURGi project developed common research protocols. The data obtained allowed for a comprehensive assessment of the potential for RNFs to replace mineral fertilizers and support sustainable crop production. More information can be found on the project website (https://interreg-baltic.eu/project/cinurgi/) and in a video by our partner, RENDBEN Sp. z o.o., which showcases the implementation and testing of a pilot line for producing pelleted fertilizers from waste—a product we subsequently tested in a research greenhouse: https://www.youtube.com/watch?v=Y2AK7AqtPuU

Publications produced as part of the project to date:

1. Ksawery Kuligowski, Ewa Wojciechowska, Nicole Nawrot, Joanna Strycharz, Jacek Kluska, Adam Cenian. 2025: Recycling organic waste to biochar amended soils stabilizes Miscanthus x giganteus growth. Renewable and Sustainable Energy Reviews, Volume 215, June 2025, 115581. https://doi.org/10.1016/j.rser.2025.115581
2. Kuligowski Ksawery, Quoc Ba Tran, Chinh Chien Nguyen, Piotr Kaczyński, Izabela Konkol, Lesław Świerczek, Adam Cenian, and Xuan Cuong Nguyen. 2025. "Analyzing and Predicting the Agronomic Effectiveness of Fertilizers Derived from Food Waste Using Data-Driven Models" Applied Sciences 15, no. 11: 5999. https://doi.org/10.3390/app15115999
3. Kuligowski, K., Woźniak, A., Strycharz, J., Nawrot, N., Wojciechowska, E., Cordeiro, C. M., Sindhøj, E., & Pantelopoulos, A. (2026). Yield-efficiency trade-offs for pelleted recycled nutrient fertilizers with a fermented microbial amendment: integrating nitrogen use efficiency and agronomic effectiveness. Journal of Environmental Quality, 55, e70324. https://doi.org/10.1002/jeq2.70324
4. Ksawery Kuligowski, Adrian Woźniak, Joanna Strycharz, and Nicole Nawrot. 2026. "Agronomic Performance of Pelleted Multi-Ingredient Organic-Mineral Recycled Nutrient Fertilizers, Enhanced with Seafood-Waste-Containing Chitosan" Applied Sciences 16, no. 21: 10478. https://doi.org/10.3390/app162110478