Sustainable eggplant cultivation: Distinct effects of foliar and root applications of alkaline-extracted bioproducts from digestate

Increasing crop yields and quality, and reducing the doses of mineral fertilizers are two main concerns to counteract the environmental negative effects. The present study reports the use of bioproducts (BPs) extracted by alkaline hydrolysis from food waste anaerobic digestate in the cultivation of eggplants in a cold greenhouse, aiming to reduce chemical inputs in agricultural practices. Two application methods, root and foliar, were compared. The effect of solid BPs was also evaluated, reducing by 40% the regular fertilization used for the common production of eggplants in Sicily. The results suggested that BPs allow reducing up to 40% mineral fertilization, without critically affecting the plant performance, fruit yield, and even ameliorating the quality of the fruits. These findings suggest that BPs can act as sustainable biostimulants providing evidence for integrating bioproducts into circular bioeconomy strategies, reducing fertilizer dependency, and contributing to environmentally friendly agriculture.