Valorisation of production residues from the cork stoppers industry: potential use as a growing-media component for potted plants

This study highlights the valorisation of two production residues from the cork stoppers industry, as components of peat-reduced growing-media (substrate) for potted plants. “High-density cork granulates” (CG) and “Terras residue” (TR) were studied, and their physical and chemical properties and their effect on plants growth (Cress, Chinese cabbage, Stone pine and Maritime pine) were evaluated. For this purpose, the residues were mixed with peat at 0, 25, 50, 75 and 100 % (vv^-1). Substrates containing 25 % (vv^-1) of CG and TR showed an adequate air content and water availability, no phytotoxicity (Cress germination test), a satisfactory growth and no nitrogen immobilisation (Chinese cabbage trial) and a good performance of Pine seedlings (Stone pine and Maritime pine trial). Results suggest that production residues from the cork stoppers industry can replace peat up to 25 % (vv^-1), resulting in significant savings in substrates for production nurseries without affecting the growth and performance of plants.