Soil degradation caused by anthropogenic disturbance compromises essential ecosystem functions, including nutrient cycling, soil biological activity, and plant productivity, making restoration of degraded soils a major ecological challenge. This study, conducted within the EMBRACE project (PRIN PNRR 2022), evaluated the potential of a novel lumbricompost derived from Posidonia oceanica residues to promote the ecological restoration of a limestone quarry substrate in Padula (Southern Italy). The experimental field comprised 15 plots in a randomized block design, including treatments with lumbricompost, lumbricompost + zeolite, stabilized sludge, stabilized sludge + zeolite, untreated control. Natural zeolites were added to improve amendment quality and enhance soil restoration efficiency. Over a one-year period, vegetation recovery was monitored seasonally through aerial imaging and phytosociological surveys, while soil samples were analyzed for physicochemical properties, phytotoxicity, enzymatic activities, and community-level physiological profiles (CLPP).

Amended plots showed higher revegetation than controls, particularly during summer and autumn. Plots with zeolite exhibited greater plant biomass production six months after treatments, suggesting a positive role of zeolite in improving amendment performance. Soil organic matter increased in all amended plots, while microbial indicators highlighted a rapid activation of edaphic community. Hydrolase and β-glucosidase activities were higher in treated soils, and CLPP analyses revealed enhanced microbial metabolic activity under lumbricompost application, especially for carbohydrate and carboxylic acid utilization. In contrast, control soils maintained low microbial activity and distinct functional profiles.

Results indicated that marine lumbricompost rapidly stimulates soil microbial activity and promotes vegetation establishment, supporting a bottom-up recovery process from microbial activation to plant colonization. The results were comparable to that observed with stabilized sludge, an organic amendment commonly used in remediation practices. However, the partial return of microbial indicators toward initial conditions over time suggests mainly short-term effects, highlighting the need for repeated amendments and long-term monitoring to ensure stable rehabilitation of degraded substrates.