Winemaking is one of the most relevant socio-economic activities in the world, particularly in countries such as Portugal, generating substantial amounts of by-products across its various phases. Managing these by-products presents significant environmental, ecological, and economic challenges. Vermicomposting, the use of earthworms to process and transform organic wastes into nutrient-rich end-products, provides a viable alternative for waste management within the wine sector. This bioprocess also produces vermicompost that enhances soil health and fosters optimal conditions for plant growth, thereby promoting resilient and sustainable viticulture practices. This review explores the various by-products produced by the vine and wine industry, highlighting the potential of vermicomposting. Remarkably, grape marc, the primary solid waste of the winemaking process, has been the most commonly vermicomposted material. In contrast, other vineyard and wine cellar by-products have been comparatively underutilized and understudied in this context. However, we hypothesize that all vine and wine industry by-products have vermicomposting potential, allowing for the production of fertilizers and soil amendments. This approach aligns with the principles of the circular economy, ensuring that all materials stemming from viticulture and wine production are valued and reused, thereby contributing to enhanced sustainability and the preservation of resources like soil.

Sewage sludge (SS) is a by-product of wastewater treatment processes (WWTPs) and is rich in organic matter and essential nutrients like nitrogen, phosphorus, and potassium, making it a potential fertilizer for agricultural use. However, its application is often limited due to the presence of pathogenic bacteria, viruses, metals, and organic contaminants that can accumulate in soils and crops, raising concerns about food safety. Sewage sludge is additionally challenging to handle due to its high moisture content, low density, and odor emission. To mitigate environmental risks and enhance its usability as a soil fertilizer, SS must be stabilized. Various techniques, including chemical, physical, and biological, can be used to stabilize SS. The addition of lime and composting has received particular attention among these techniques owing to the benefits they offer. Both methods effectively control and eliminate pathogens and reduce metal bioavailability, thus improving their agricultural utility. This review emphasizes the importance of using SS for agricultural purposes, placing particular focus on the procedures of composting and liming to stabilize and enhance the quality of SS, hence promoting its safety.

Vermicomposting aims to convert organic residues into valuable end products within a circular economy-based framework. Vineyards generate significant amounts of by-products, namely vine prunings (VPs), typically landfilled or incinerated, and rotten grape clusters (RGCs), which stay on the vines until removed by pruning. This pilot-scale study aimed to explore the role of two earthworm species (Eisenia fetida and Eisenia andrei) in transforming VP and RGC substrates by evaluating their physicochemical properties, phytotoxicity, and polyphenolic content before and after vermicomposting and the microbial activity at the end of the process. The substrates were vermicomposted in 2 L containers with coconut fiber (1:1 ratio) and 7.5 g of each earthworm species (clitellated and non-clitellated) per container for 100 days, with the earthworm biomass monitored every other week. Phytotoxicity was assessed using garden cress (Lepidium sativum L.) and lettuce (Lactuca sativa L.) seeds, and biological stability was assessed by microbial activity and polyphenolic content evaluation using the Folin–Ciocalteu method. The results showed that differences in the vermicompost properties were primarily substrate-dependent. The RGC-based vermicomposts exhibited higher electrical conductivity and P, K, S, and B levels, while the VP-based composts had higher C/N ratios. E. fetida produced vermicomposts with significantly higher K, Ca, and Mg contents and consistently lower phytotoxicity in germination assays with garden cress and lettuce, compared with E. andrei. Vermicomposting led to a decrease in polyphenolic content for both species. This study highlights the importance of earthworm species selection for vermicomposting vineyard residues. Further research should explore how these species perform with other residues to understand their suitability for producing high quality vermicomposts.

Recycling vineyard pruning residues into compost and vermicompost represents a sustainable strategy to reduce viticulture’s reliance on chemical fertilizers. Nonetheless, their effects on plant performance remain poorly understood. This study evaluated the effect of vine pruning residues compost and vermicompost on the physiological, biochemical, and growth performance of Vitis vinifera L. cv. Touriga Franca, in comparison with mineral fertilization and an unfertilized control. A pot experiment was conducted from April to September 2024 in northern Portugal under Mediterranean climate conditions, using one-year-old grapevines and subjected to four fertilization treatments. Leaf gas exchange, chlorophyll a fluorescence, photosynthetic pigments, antioxidant and osmoprotective metabolites, and shoot and root development were assessed at three sampling dates during the growing season. Organic amendments enhanced photosynthetic performance and root growth relative to the unfertilized control. Vermicompost promoted higher CO₂ assimilation, stomatal conductance, and shoot and root elongation, whereas compost increased intrinsic water use efficiency, photochemical regulation, and root biomass. Biochemical analyses indicated that compost favored protein and carotenoid accumulation, while vermicompost increased proline and later protein levels, alongside reduced phenolic and flavonoid contents. Despite their similar chemical composition, compost and vermicompost induced distinct physiological responses driven by differences in biological activity and nutrient dynamics. These findings demonstrate that pruning-derived organic amendments can match mineral fertilization in supporting grapevine performance while offering additional benefits for stress regulation and sustainable vineyard management.

The replacement of peat in horticultural substrates is a priority for sustainable plant production. This study evaluated compost and vermicompost, derived from vine pruning and sewage sludge, as partial peat substitutes in cucumber (Cucumis sativus L.) seedling production. Germination, early growth traits, growth efficiency indices, and leaf nutrient contents were assessed, and the relationships among variables were explored using correlation analysis and principal component analysis. Five substrates were tested: peat-perlite alone (control) and mixtures containing 10%, 20%, or 40% compost or vermicompost as peat replacements. Results showed that incorporating 10% vermicompost significantly improved germination, seedling vigor, and biomass accumulation, with performance comparable to, or exceeding, the control. In contrast, higher proportions of compost or vermicompost negatively affected germination and seedling quality. Nutrient analysis revealed that 10% vermicompost enhanced Ca and K accumulation, traits positively correlated with growth, whereas 20% compost and 20% vermicompost were associated with higher P and Mg contents but reduced seedling performance. Overall, these promising findings demonstrate that a low proportion of vermicompost (10%) is sufficient to successfully partially replace peat in cucumber seedling production, benefiting both performance and sustainability, whereas higher compost or vermicompost levels disrupt nutrient balance and limit this species’ growth.

Invasive alien species are one of the main threats to global biodiversity, and pose significant management challenges in several areas outside their natural range. In southern Mediterranean Europe, the invasion of Acacia species is particularly severe and its control requires costly and often ineffective actions. The use of vermicompost derived from these species to replace peat-based substrates in horticulture offers a promising alternative to mitigate their economic and environmental impacts while enhancing the sustainability of their control. This study explored the potential of vermicompost produced from the fresh aboveground waste biomass (leaves + stems + flowers) of Acacia dealbata and Acacia melanoxylon (75:25 w/w), two of the most aggressive Acacia species in the Mediterranean, using Eisenia fetida over twelve weeks. In essence, this study aimed to evaluate the quality of the produced vermicompost and its suitability as a partial substitute for potting substrate in the production of cucumber (Cucumis sativus) seedlings for transplant. Four substrate mixtures containing 0%, 10%, 30%, and 50% of Acacia vermicompost (w/w), combined with commercial peat-based potting substrate and perlite (20%) were tested in polystyrene seedling trays. Seedling emergence, growth, and leaf biochemical parameters (photosynthetic pigments, phenolics, soluble sugars and starch, and total thiobarbituric acid-reactive substances—TBARSs) were evaluated. The results showed that the addition of Acacia vermicompost to the commercial substrate did not affect its germination but significantly enhanced seedling growth, particularly in mixtures containing 30% and 50% Acacia vermicompost. In addition, the absence of accumulation of TBARSs also reflected the superiority of these two treatments. These findings suggest that vermicompost derived from A. dealbata and A. melanoxylon biomass can be a viable peat-based substrate alternative for horticultural production, with the dual benefit of promoting sustainable agricultural practices and contributing to invasive species management.