Determination of the effects of bi̇ogas waste application on fruit and oil yield of olives (Olea europaea l.) grown in irrigated and dry conditions

The aim of the study was to investigate the effects of applying two different doses of biogas waste fertilizer obtained from fermentation to irrigated and non-irrigated trees of the Gemlik olive variety at different periods on yield per tree, fruit quality parameters, and oil quality. The study investigated yield and 100-berry weight, fruit flesh and weight, fruit flesh/seed ratio, dry matter analysis, oil yield, and fatty acid composition of fertilization and irrigation treatments. The experiment was conducted in a farmer's Gemlik olive orchard (36'80' N, 35'61' E, 516 m) in Adana province, under Mediterranean climate conditions during the 2024 vegetation period. At the end of the study, it was investigated whether biogas waste, an agricultural input, could be used in solid form as an alternative organic fertilizer alongside other organic fertilizer materials in olive cultivation under irrigated and dryland conditions in the Yuregir region of Adana. Consequently, it was determined that applying 14 kg of biogas waste fertilizer under irrigated conditions was significant and recommendable in this context, considering all the investigated parameters.