Prospects for the agroecological use of digestate after anaerobic digestion of coffee production waste

This study investigated the anaerobic biodegradation of coffee production waste as a method for producing a high-quality biofertilizer. The resulting digestate was characterized in terms of trace element concentrations, amino acid profile, phytohormone and fulvic acid content, microbiological composition, and heavy metal levels. Bioindication experiments were conducted using ryegrass (Lolium perenne L.), a category I monocotyledonous indicator plant. Dark gray podzolized soil, digestate, and a natural sorbent (natural zeolite from the Sokyrnytskyi deposit) were used as experimental substrates. Comprehensive quality assessment demonstrated that the digestate meets the criteria for a high-quality organic fertilizer, exhibiting a rich chemical composition and environmentally safe properties. The highest mean values of plant growth and development parameters were recorded in treatments containing zeolite, indicating a synergistic effect of digestate and zeolite application on plant performance.