Low-value production residues from the cork industry: potential raw materials for the growing-media industry?

The cork industry produces several low-value production residues unsuitable for high-end applications due to properties like high density and mineral contamination. This study explores the potential use of two residues: high-density cork granulates (CG) and cork inner bark (CI) as components in growing-media for soilless culture. Their physical and chemical properties were characterised following European Standards. Both materials showed high porosity and low water retention, making them suitable for improving aeration and drainage in substrates. They also contributed essential nutrients, which may reduce the need for additional fertilisation. These results highlight the potential of these raw materials as sustainable, renewable alternatives in growing-media, supporting circular economy strategies and enhancing resource efficiency.