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.

The valorization of agro-industrial residues and sewage sludge into value-added products through vermicomposting represents a promising strategy for nutrient recycling and waste reduction. This study evaluated the effects of aqueous extracts obtained from five vermicomposts (VC1-VC5) produced from different mixtures of vineyard and winery residues and sewage sludge on cucumber (Cucumis sativus L.) seedlings grown under in vitro conditions. The aqueous extracts (10%, w/v) were characterized in terms of pH, electrical conductivity, and total polyphenolic content, and applied to cucumber seedlings cultivated for 30 days under sterile and controlled in vitro conditions using commercially available peat pellets (Jiffy-7^®). Seedling development was monitored throughout the experiment, and morphological and biochemical parameters were assessed at the end of the 30-day assay. All extracts supported seedling development, with no evidence of phytotoxicity. The application of VC2 and VC4 extracts resulted in significant increases in fresh and dry weight, while VC2 led to higher chlorophyll and carotenoid contents. Conversely, VC3 and VC5 extracts were associated with slight reductions in growth parameters and photosynthetic pigment content. Correlation analysis suggested positive associations between biomass accumulation and chlorophyll content, and negative association between total polyphenolic content and stem growth. Overall, the results indicate that aqueous vermicompost extracts were not phytotoxic under the tested conditions, although their effects appear to depend on extract composition, highlighting the importance of feedstock selection for sustainable horticultural applications.

Winery residues generated by the wine industry represent an important sustainability challenge but also a valuable resource for producing vermicompost-derived products with potential agricultural applications through vermicomposting. This study evaluated the effects of aqueous vermicompost extracts produced from winery residues on the early in vitro development and physiological performance of garden cress (Lepidium sativum L.) and cucumber (Cucumis sativus L.) seedlings. Seedlings were cultivated on peat-based pellets (Jiffy-7^®) under controlled conditions and treated with two extract concentrations (10% and 20%, w/v) or distilled water (control). After 30 days, morphological traits (shoot height, leaf number and biomass) and biochemical parameters (photosynthetic pigments and total phenolics) were assessed. Both species showed high survival rates (>85%) and no phytotoxic symptoms. Compared with the control, VE20% increased chlorophyll a, chlorophyll b, and total chlorophyll contents in garden cress by 40.3%, 35.9%, and 38.9%, respectively, whereas VE10% increased chlorophyll a, total chlorophyll, and carotenoid contents in cucumber by 15.7%, 11.5%, and 25.0%, respectively. Total phenolic content did not differ significantly among treatments in either species (p > 0.05). These findings indicate that vermicompost extracts produced from winery residues exhibited low phytotoxic potential under the experimental conditions tested and influenced photosynthetic pigment accumulation without adversely affecting seedling growth. These responses warrant further investigation under ex vitro and field conditions to determine whether the observed physiological changes translate into relevant agronomic effects.

The sustainable management of organic residues remains a major challenge in agriculture. Vermicomposting offers an environmentally friendly strategy to convert organic waste into nutrient-rich, biologically stable biofertilizers. This exploratory study evaluated the effects of vermicompost and its leachate, produced from sewage sludge and vineyard pruning residues, on cucumber (Cucumis sativus L.) germination and 25-day early seedling growth. Treatments included a control (peat and perlite, CNT), two vermicompost doses, 20 g kg⁻¹ and 40 g kg⁻¹ (VC_D1 and VC_D2, respectively) and a 5% (v/v) vermicompost leachate (VC_L) applied as the sole irrigation source. Foliar nutrient contents and physicochemical properties of the substrate and leachate were determined. Germination was not significantly affected (p > 0.05), but VC_D1 promoted slightly faster and more uniform seed emergence. Growth responses were dose dependent, with VC_D1 significantly enhancing shoot biomass (approximately 15% than the CNT and VC_D2) and providing a balanced foliar nutrient profile, whereas VC_D2 significantly reduced growth, promoted excessive foliar K and P, and lower Ca, Fe, and Mn contents. VC_L enhanced foliar N accumulation but did not significantly (p > 0.05) increase biomass. Both vermicompost and its leachate were pathogen-free, with metal concentrations below regulatory limits. Overall, these findings suggest that, under the tested conditions, vermicomposting these residues can generate potentially safe amendments for cucumber seedling growth, though dose optimization is essential. This exploratory approach supports residue valorization and contributes to circular economy principles and sustainable agriculture goals.