Constructed Vegetated Soils from Waste to Preserve the Natural Soil Resource

This study assesses the physical and hydrodynamic properties of constructed soils made from organic and mineral wastes and their impact on urban plant growth. Two experiments were conducted since 2005 in 500-L lysimeters planted with trees: the first evaluated growth media containing 40% volume organic inputs (green waste compost or sludge/wood chip co-compost) mixed with topsoil, while the second tested support soils with up to 70% stony waste (chalcedony, demolition rubble, or used railway ballast). Results highlight that compost type and maturity critically influence macroporosity and microporosity, aiding root aeration and water retention, and that soil-stone mixtures reduce compaction risk and support robust root development.