The environmental sustainability of bio-based fertilisers produced via integrated nutrient recycling technologies

Bio-based fertilisers (BBFs) have been promoted by the EU as an emerging and promising solution to help manage bio-waste problems (by converting organic wastes to nutrient-rich products) and simultaneously substitute or reduce the use of mineral fertilisers. They are also considered as an effective tool for improving soil health conditions in Europe. By taking a full life cycle perspective, this paper investigates whether valorising biological waste streams to recover valuable components for the production of BBFs is indeed environmentally justified and can bring benefits to the soil and the environment. The environmental aspects of BBF were inves tigated by undertaking a Life Cycle Assessment (LCA) and supplemented with additional agronomic results from field trials. The LCA results indicate that the large difference in application rates (up to 35 times more by weight BBFs were applied than conventional fertilisers) disfavours waste-derived BBFs compared to mineral and organo-mineral fertilisers. On the other hand, the inclusion of biochar as a component of BBFs has a pronounced effect on the climate change and thus overall environmental performance of BBFs significantly increasing their attractiveness. Although associated with uncertainties, this paper provides useful insights to farmers, academics, policymakers and other stakeholders whether (and under what conditions) the production and application of waste-derived BBFs can enhance soil health, improve nutrient availability, and reduce reliance on synthetic fertilisers. It also provides LCA data for new biomass treatment technologies and materials, which is highly valuable for other researchers interested in recycling of organic wastes for sustainable BBF production and farming.