SSOIL

The SSOIL project is a forward-looking initiative aimed at increasing the sustainability of the agri-food sector by designing and deploying compact, robust solid-state fermentation (SSF) equipment for the on-site valorization of agri-food wastes, including pruning residues. The core concept is to transform organic waste streams into high-value, compost-like materials enriched with macronutrients, organic carbon, and biostimulants, thereby closing nutrient loops and reducing environmental impact.

SSF technology is recognized as an efficient and environmentally friendly approach for converting solid organic waste into marketable products such as biostimulants. Among these, the fungus Trichoderma harzianum has demonstrated robust production of indo-3-acetic acid (IAA), a potent plant biostimulant, when grown on green waste substrates rich in biodegradable organic matter and nutrients. The SSOIL project builds on the successful validation of SSF for green waste valorization in previous European projects like DECISIVE, SCALIBUR, and ReLEAF.

A unique aspect of SSOIL is its use of both unprocessed and nutrient-enriched wood as bulking agents in the SSF process. Unprocessed pruning wastes, such as grape stalks, are first employed as wood-based adsorbents to capture nutrients from Wastewater Treatment Plant (WWTP) effluents. Once saturated, these wood wastes are incorporated into the SSF process, where they contribute to the production of a functionalized compost-like material. This approach not only valorizes two waste streams—agri-food and pruning residues—but also provides a novel route for the reuse of nutrient-laden wood, which has previously lacked a well-established valorization pathway.

The project will optimize the selection of wood granulometry and operational SSF conditions at laboratory scale using real samples. The optimized process will then be scaled up to a 22-liter SSF reactor capable of producing up to 150 kg of functionalized compost-like material, which will be subjected to agronomic testing to validate its efficacy as a biofertilizer and biostimulant.

SSOIL is led by AERIS, an SME with a strong track record in developing and commercializing environmental technologies and turnkey solutions. The project also benefits from the expertise of leading technology developers such as Leitat (coordinator of ReLEAF) and UAB (partner in DECISIVE and SCALIBUR), ensuring a high level of scientific and technical innovation. The involvement of the experimental farm Sa Canova and the CLIQIB cluster guarantees that the technology is validated under real-world conditions and aligned with the needs of end-users.

To accelerate the adoption of SSOIL technology, the project will explore intellectual property protection strategies and exploitation routes, aiming to increase the incomes of both AERIS (as technology provider) and Sa Canova (as waste owner and end-user). By providing a clear pathway for technology transfer and commercialization, SSOIL positions itself as a transformative solution for sustainable waste management in the agri-food sector.

In summary, SSOIL will deliver a science-backed, scalable, and user-friendly SSF system for the on-site conversion of agricultural and pruning wastes into valuable compost-like materials, supporting circular economy goals, enhancing soil health, and boosting the economic resilience of stakeholders in the agri-food value chain