Waste utilization in sustainable agriculture and CO2 fertilization: a case study of tomato cultivation

This study was conducted to investigate the effects of CO₂ gas obtained from compost on the growth and yield of tomato plants under greenhouse conditions as part of sustainable agriculture practices. The research was carried out in three separate greenhouses located on the campus of Alanya Alaaddin Keykubat University. In Greenhouse 1 and Greenhouse 2, CO₂ gas generated from compost tanks was applied, while Greenhouse 3 was evaluated as the control group. The CO₂ gas produced in the tanks was introduced into the greenhouse environment for 50 days, five times daily in 10-minute intervals. During this period, the average CO₂ concentrations were measured as 558.46 ppm for Greenhouse 1, 544.52 ppm for Greenhouse 2, and 469.18 ppm for the control group (Greenhouse 3). Compared to the control greenhouse, the CO₂-applied greenhouses achieved an approximate 17.54 % increase in CO₂ concentration. At the end of the application, significant differences were observed in terms of plant height, stem diameter, and yield. Compared to the initial values, plant height reached 104.50 cm in Greenhouse 2, 80.67 cm in Greenhouse 1, and remained at 79.75 cm in the control group. The average stem diameter was measured as 14.44 mm in Greenhouse 1, 15.01 mm in Greenhouse 2, and 13.70 mm in the control greenhouse. Over seven harvesting periods, the total tomato yield was recorded as 5.381 t/ha in Greenhouse 1, 4.774 t/ha in Greenhouse 2, and 3.268 t/ha in the control greenhouse. Based on these results, Greenhouse 1 achieved 64.63 % higher yield, and Greenhouse 2 achieved 45.15 % higher yield compared to the control greenhouse. The findings of the study revealed that compost-based CO₂ gas applied in greenhouse conditions had a positive and statistically significant effect on the growth parameters and total yield of tomato plants.