Physical and Chemical Properties of Limestone Quarry Technosols Used in the Restoration of Mediterranean Habitats

The lack of topsoil is frequently a limiting factor in limestone quarry restoration. This implies that new technosols for maintaining target habitats must be created using mining wastes as the main components. We designed three different technosols using different combinations of mineral materials (mining wastes, excavated soils and topsoil), organic amendment types (compost and digestate) and doses for the restoration of target habitats. Moreover, we monitored the main physicochemical indicators of the quality of the technosols. We observed not only an increase in soil organic carbon and plant nutrients related to the application of any type of organic amendment, but that the digestate mostly increased the soil resistance to erosion by improving soil aggregation even before the emergence of vegetation. Soil-water-retention capacity only improved in technosols built with organic amendments and topsoil. The combination of mining wastes, organic amendments and a superficial horizon of topsoil resulted in the most optimal technosol for the restoration of limestone quarries in the Mediterranean climate.