Reusing greenhouse growing media

The disposal of used growing media represents one of the weak points for the application of hydroponic technology to greenhouse and nursery production. In many cases, especially mineral wools, exhausted substrates are disposed to landfill. However, landfill costs are increasing and landfill sites are becoming ever more unavailable. Thus, substrate reutilization must be strongly encouraged along with the reduction of substrate volume applied per plant. The paper reports a literature survey on the biological, technological and environmental implications of the reuse of exhausted substrates in soilless culture.