Circular Economy Chains Based on Agricultural, Livestock and Food By-products in Crete

Crete is a key agricultural region in Greece, characterized by smallholder farms, greenhouse cultivation, and extensive livestock farming, especially sheep and goats. Despite its rich agri-food production, the region faces serious environmental, economic, and climatic challenges. Large volumes of valuable biomass—such as sheep wool, legume crop residues, and food processing by-products—are discarded due to the absence of processing infrastructure and circular economy mechanisms. This results in environmental degradation, lost resources, and missed economic opportunities.

At the same time, local agriculture remains heavily reliant on imported synthetic inputs, which are costly, often unsuited to local conditions, and contribute to soil and water degradation. Water scarcity, intensified by the Mediterranean climate, further stresses agricultural systems and highlights the urgent need for improved soil moisture retention and reduced input dependency. Existing circular economy trials remain isolated, lacking systemic application or stakeholder engagement.

The CSSBoost demonstrator was launched to address these agro-environmental, hydrological, and socio-economic challenges through three circular value chains. By converting waste into value-added products and aligning with the Water-Food-Ecosystem pillars of the WEFE Nexus, the initiative aims to strengthen resilience, reduce environmental impact, and create scalable, sustainable solutions tailored to Crete’s conditions. 

The main aim of the CSSBoost demonstrator is to implement three interconnected circular value chains that valorize underutilized biomass in Crete's agri-food sector. These include:

• Transforming sheep wool waste into biodegradable soil enhancers that improve water retention and support organic fertilization.
• Converting agricultural residues, particularly from fava beans, into green manure enriched with bio-stimulants, reducing the need for chemical fertilizers.
• Repurposing oat and carob processing by-products into enriched dough for healthier bakery products with improved nutritional profiles and low glycaemic index.

These interventions directly contribute to three pillars of the WEFE Nexus: Water, Food, and Ecosystems. Water is addressed through improved soil moisture retention, food through the creation of sustainable and nutritious products, and ecosystems through reduced waste, chemical inputs, and enhanced soil health.

The project’s short-term goal is to establish these value chains through pilot implementation, stakeholder training, and field trials in Crete. The long-term goal is to scale and replicate the model across other Mediterranean regions facing similar challenges. Stakeholder consultations, including farmers, researchers, food producers, and retailers, have been integral in co-designing the solutions to ensure technical relevance, economic feasibility, and adoption at the local level. The timeline spans from 2024 to 2027, with measurable impact already underway through early implementation activities. 

The CSSBoost demonstrator has progressed from design to implementation across all three targeted value chains, combining technical installations with stakeholder engagement:

1. Sheep Wool Valorisation: Over 100 tons of lamb wool were collected from local farms. A low-energy pelletizing system was deployed to produce biodegradable wool-based soil enhancers, designed to improve water retention and gradually release nutrients. These pellets were tested in agricultural plots for effectiveness on soil moisture and crop yield.
2. Green Manure Production: A biostimulant-enhanced green manure system was introduced using fava bean residues, following an intercropping protocol where fava beans are grown first and incorporated into the soil to enrich it before planting tomatoes. This regenerative approach increases soil fertility and reduces dependency on synthetic fertilizers.
3. Food By-product Transformation: By-products from oat and carob processing were repurposed into enriched dough for bakery products, in collaboration with Mills of Crete. The dough, high in fiber and with a low glycaemic index, was used to produce healthier baked goods aligned with circular nutrition goals.
4. Digital Monitoring Tools: To support smart agriculture practices, LoRaWAN-based sensors were installed in selected plots to monitor soil moisture, temperature, and other environmental parameters, enhancing data-driven decision-making for farmers.
5. Soft Interventions: More than 20 stakeholders, including farmers, researchers, SMEs, and retailers, were engaged through co-design workshops, training sessions, and field demonstrations. These activities ensured that technical solutions met local needs and increased adoption potential.

The project followed a structured implementation sequence: initial material mapping and collection, pilot system setup (wool processing, intercropping, food formulation), followed by stakeholder training and field deployment. These actions collectively address key WEFE pillars: reducing water stress, improving soil ecosystems, and supporting sustainable food systems through circular bioeconomy practices. 

The CSSBoost demonstrator has achieved tangible results across multiple dimensions of the WEFE Nexus through the implementation of circular value chains:

• Water & Ecosystem Impact: Over 100 tons of lamb wool were processed into biodegradable pellets and successfully used in agricultural trials. These wool pellets demonstrated significant improvement in soil moisture retention, helping farmers reduce irrigation frequency and improve drought resilience.
• Food System Innovation: A new intercropping protocol was piloted, where fava beans were cultivated and incorporated as green manure prior to planting tomatoes. This method enhanced soil organic content and improved tomato yields without the use of synthetic fertilizers. It also supported soil biodiversity and nutrient cycling, reinforcing ecosystem health.
• Circular Nutrition: In partnership with Mills of Crete, by-products from oat and carob processing were repurposed into enriched bakery dough. The resulting low glycaemic index bakery products offer higher nutritional value and cater to growing consumer demand for functional, sustainable foods.
• Cross-sectoral Collaboration: The project fostered strong collaboration among research institutions, agri-processors, farmers, and retailers. Over 20 stakeholders participated actively through co-design sessions, technical workshops, and field trials, building capacity for circular innovation.
• Visibility and Awareness: The demonstrator significantly raised awareness of the potential for circular economy practices in the agri-food sector. It served as a practical example of how locally available materials can be transformed into marketable, sustainable products, stimulating interest among policymakers, agricultural cooperatives, and innovation hubs in the Mediterranean region.

Collectively, these outcomes confirm that the project is on track to meet its objectives, with high relevance to regional sustainability goals and strong potential for replication and scaling in similar agricultural contexts. 

The CSSBoost demonstrator offers several valuable lessons for implementing WEFE Nexus-based circular interventions in Mediterranean agri-food systems. A key insight is that early and continuous involvement of farmers in the co-design and testing of solutions significantly increases local ownership, adoption, and contextual adaptation. Farmers not only provided input on practical feasibility but also acted as multipliers within their communities, improving dissemination and peer learning.

The initiative has the potential to demonstrate strong scalability and replicability, especially in regions with small-scale farming, diversified crops, and livestock systems, similar to Crete. Its low-tech and relatively low-cost innovations, such as wool-based soil enhancers and green manure protocols, require minimal infrastructure and can be easily adapted to local conditions and biomass availability. These features make the approach highly transferable across rural Mediterranean areas.

However, the project also revealed the importance of early regulatory planning, particularly in areas involving organic inputs and food products. For example, the transport and processing of lamb wool required HACCP-aligned procedures, which caused delays when not addressed in advance. Future replication should include a proactive regulatory roadmap from the outset.

The CSSBoost model aligns strongly with EU priorities for a circular bioeconomy, sustainable food systems, and the WEFE Nexus, making it an attractive case for both regional and national policy scaling. Its integrated, cross-sectoral design, bridging agriculture, food, water, and ecosystems, provides a practical and adaptable template for sustainable transformation in other parts of Southern Europe, North Africa, and the broader Euro-Mediterranean region. 

CSSBoost demonstrates how low-tech, circular solutions can effectively reduce environmental impact and improve resource efficiency in agriculture. These real-world results can guide policy design by highlighting the benefits of supporting on-farm biomass valorisation and biobased soil inputs. The project’s regulatory experience, especially with HACCP compliance for wool processing, can inform frameworks that streamline approval processes for circular products. Additionally, the pilot showcases the value of investing in small-scale infrastructure (e.g., pelletizers, sensors) and capacity building for farmers, which can be integrated into rural development funds, green transition strategies, or EU Common Agricultural Policy (CAP) instruments. It serves as a blueprint for evidence-based regulations and investment planning that support the WEFE Nexus and the EU Green Deal.