The project Circular NP – Better nutrient cycle for animal manure is coming to an end. But even though the project is about to end, the search for the biofertiliser of the future will continue – and on a larger scale. We spoke to Helena Aronsson, Senior Lecturer at the Swedish University of Agricultural Sciences and Coordinator of Circular NP, for an update on the project’s latest progress.
It has been five eventful years since the launch the project Circular NP – Better nutrient cycle for animal manure. The project started in 2020 with the overall goal of reducing the dependency on mineral fertilisers as a step in the chain of reducing nutrient leakage from agriculture, which is the single largest source of eutrophication of the Baltic Sea.
– We wanted to develop methods to recycle nutrients in agriculture by developing new effective biological fertiliser products, says Helena Aronsson, Senior Lecturer at the Department of Soil and Environment.
Developing a circular alternative to mineral fertilisers has been a major technical challenge. But the scope of the project has gone beyond that.
– For farmers to want to use them, the products need to be at least as effective as mineral fertilisers. But at the same time, they need to be produced and transported in a sustainable and cost-effective way, she says.
– It’s been important to take a holistic approach to developing products that actually work in practice, Helena explains.
Agricultural specialisation has created a nutrient imbalance
Agriculture around the Baltic Sea has become specialised, with some regions focused on intensive crop production and others on large-scale livestock farming. This has created an imbalance where animal-dense areas have a surplus of nutrients in the form of manure, while crop-intensive regions have a nutrient deficit. Despite the potential to recycle nutrients from animal manure, transport is heavy and costly, leaving crop-growing areas in need of mineral fertilisers. At the same time, excess nutrients in animal-dense areas risk leaching out and contributing to eutrophication of the Baltic Sea.
Final trials before tying up the project
The Circular NP project is now in its final year and will end in March 2025. Although the project is coming to an end, some practical work is still in full swing. Researchers have been working intensively to develop and test different technologies to produce two types of fertiliser products: a wet, nitrogen-rich version and a drier, phosphorus-rich version. These products have been evaluated through a series of trials to examine their plant nutrient efficiency.
At the moment, there are still a few trials underway where phosphorus-rich biofertiliser products are being tested through various pot trials, says Helena.
Developing the products has been an extensive endeavour in many stages and when the last trials have been completed, Helena’s task will be to stitch together all the parts of the project into a final report.
– The project has made significant progress and we will be able to demonstrate the technical possibilities of developing nutrient-efficient circular fertilisers as an alternative to mineral fertilisers, she says
But Helena points out that there are still some challenges to overcome.
Above all, it’s about creating good market opportunities for these products. There is more work to be done here in collaboration with stakeholders from the food industry and farmers.
Method development in focus
In the search for the biofertiliser of the future, the researchers have investigated and tested a number of different techniques for separating phosphorus and nitrogen from both animal manure and digestate from the More Biogas plant. After separation, different methods have been applied to increase the fertiliser value in each fraction to obtain a dry phosphorus-rich product and a wet nitrogen-rich product.
Want to read more about the methods tested in the project? Read more here.
A springboard for large-scale work at EU level
The journey towards circular food production is long and winding, but with the results of Circular NP, several important steps are being taken in the right direction. And the journey does not end here – quite the opposite. With new knowledge under its belt, the project team is now taking the work further in an extensive international collaboration.
-The CiNURGi project, led by the Research Institutes of Sweden, focuses, like Circular NP, on enabling the efficient use of nutrients and promoting recycled fertiliser products – but this time in the entire Baltic Sea region, says Helena.
– Circular NP has been a crucial foundation for the new project and we will build on the results and products we developed in Circular NP, she explains.
CiNURGi brings together 24 partners and 13 associated organisations from eight countries around the Baltic Sea and has been granted EUR 6,5 million in funding from the EU Interreg programme.
– To reduce the nutrient load to the Baltic Sea, it is important that the change takes place throughout the region. Therefore, it feels extra important that we can take the work further on an even larger scale, she concludes.
We are looking forward to the results of Circular NP and are eagerly following CiNURGi’s work going forward!
About Circular NP
The project Circular NP – Better nutrient cycle for animal manure is carried out by BalticWaters in close collaboration with the Swedish University of Agricultural Sciences (SLU ) and the Research Institutes of Sweden (RISE).
The project aims to develop techniques to fix nitrogen and extract phosphorus from animal manure and to produce new manure products that are easier to transport over longer distances, from areas with a surplus of phosphorus to areas with a deficit.
More information on Circular NP is available on the project page.
