The use of posidonia-based compost as peat substitute for transplant production

Peat is a non-renewable resource and its extraction contributes to the degradation of wetland ecosystems. In order to reduce the peat use in nursery, two composts prepared from yard wastes were evaluated as a substrate component for producing vegetable seedlings for transplantation. Two experiments with tomato (Solanum lycopersicum L.) cultivars ‘Naxos’ and ‘TCP 9147’ and pepper (Capsicum annuum L.) cultivars ‘Solero’ and ‘Logos’ were set up in a greenhouse. In each experiment two composts were tested: “Cp”, obtained from yard wastes + beached residues of marine plant posidonia [Posidonia oceanica (L.) Delile – 20% of total fresh weight], and “C”, obtained only from yard wastes. Each compost was mixed with commercial peat in the amount of 0 (control), 25, 50, 75 and 100% (v/v). Results from the study suggest that, for both species, the best yield was obtained with the substrate prepared by mixing the peat with 25% of Cp.