Constructed Technosols are human-designed soil-like substrates created by combining mineral, organic, and/or synthetic components to deliver specific functions (e.g. water retention, contaminant immobilisation, plant growth, structural stability) where natural soils are absent, degraded, or unsuitable. They address the shortage of space for nature development and degradation in industrial or dense urban sites. Key characteristics: designed structure and composition to meet the specific requirements of the future land use; assembled either ex situ and placed on site or created in situ.
Constructed technosols should be formulated from appropriately tested secondary mineral and organic resources (excavated soils, compost, green waste, suitable industrial by-products, dredged sediments and recycled mineral materials). Their composition, depth and functional horizons should be designed according to the intended land use and required soil performances (vegetation establishment, root development, water infiltration and storage, carbon storage, pollutant retention and urban cooling). Where appropriate, biochar and engineered soil–aggregate mixtures can be incorporated to enhance specific soil functions, provided that their environmental quality and compatibility with the intended use are demonstrated. Land-use applications may include urban parks, street-tree systems, bioswales, green and biosolar roofs, and the requalification of suitable brownfield and post-industrial sites for non-food biomass production.