Hydroponic Cultivation of Vine Leaves with Reduced Carbon Footprint in a Mediterranean Greenhouse

Vine leaves are considered a delicacy food however they are only produced as a byproduct for a short harvest period due to grape cultivation practices and numerous chemical applications. In this work, vine plants were cultivated hydroponically in a greenhouse, to extend the cultivation period and along with high plant density, maximize fresh leaves yield. Four different substrates were tested—Perlite, Perlite-Attapulgite, Perlite-Zeolite, 1.7Perlite-higher density planting—with soil treatment as a control, and the experimental cultivation lasted a total of about seven months in the year 2021. Quantitative and qualitative characteristics such as leaves number and weight, color of leaves, nitrates, photosynthetic parameters, total phenols, and plant nutrient concentrations were assessed, while the product’s environmental impact was calculated. The 1.7Perlite treatment produced a 1.6–2.0 times higher number of leaves per hectare than the other hydroponic treatments and 8.7 times higher than the soil treatment, while no statistically significant differences were found regarding qualitative characteristics. Consequently, the 1.7P treatment resulted in a 1.4 to 7.6 times lower product carbon footprint compared to the other treatments. In future research, substrates water and nutrient retention will be further studied along with year-round production in a heated greenhouse with full climate control so that plants are kept evergreen.