Work Package 3

Agriculture remains fundamental to global food production; however, the sector is increasingly challenged to reduce greenhouse gas emissions, improve resource efficiency, and promote the transition towards more circular and sustainable production systems. Within livestock farming, manure management represents a critical aspect, as manure can either serve as a valuable resource or become a major source of environmental impacts depending on the management practices applied. In this context, the University of Santiago de Compostela is leading WP3 of the NUTRITIVE project, focusing on the life cycle assessment (LCA) of manure management technologies. The objective of this work package is to evaluate and compare the environmental performance of different manure treatment pathways, ranging from conventional management practices to innovative circular solutions. Through the application of LCA methodologies, WP3 provides a comprehensive and scientifically robust framework for assessing environmental impacts across the entire system boundary and identifying the most sustainable strategies for manure valorisation.

One of the principal achievements to date has been the development of a zero-emission farm concept based on anaerobic digestion integrated with steam methane reforming. This integrated approach enables the conversion of manure into hydrogen and biofertilizer, thereby transforming an agricultural residue into two high-value products. The hydrogen produced can contribute to meeting on-farm energy requirements, while the biofertilizer facilitates nutrient recycling and reduces dependency on synthetic fertilizers. Consequently, anaerobic digestion is positioned not only as a waste treatment technology, but also as a key component in the implementation of circular and resource-efficient agricultural systems. In parallel with the development of the zero-emission farm concept, a comparative assessment has also been conducted to evaluate the environmental impacts associated with untreated manure management. The results obtained thus far demonstrate that untreated manure generates environmental impacts that are approximately 50–66% higher than those observed under the zero-emission farm scenario. These findings clearly highlight the environmental advantages of integrating manure treatment and resource recovery technologies within livestock production systems.

Overall, the progress achieved within WP3 demonstrates the potential for manure management to evolve from a disposal challenge into a strategic pillar of sustainable agriculture. Through the NUTRITIVE project, valuable scientific evidence is being generated to support informed decision-making, improve environmental performance, and accelerate the transition towards low-emission and circular farming systems.