Synergistic Bio-Organic Fertilization Enhances Tobacco Antioxidative Defense and Soil Health for Sustainable Agriculture

The extensive use of chemical/inorganic fertilizer application over the past few decades has significantly enhanced global food production potentials. However, the excessive application of these fertilizers has resulted in environmental issues, soil nutrient imbalances, and poor quality of food. The study aimed to evaluate the impact of various blends of bio-organic fertilizer, farm manure, and compound fertilizer on soil health, focusing on soil nutrient content, soil enzymatic parameters, physio-biochemical attributes, and quality traits of tobacco. The experimental treatments incorporated different combinations of conventional compound fertilizer with organic and bio-organic fertilizers. The findings revealed that the application of these bio-organic fertilizers with various combinations to the soil significantly improved tobacco growth, photosynthetic traits, antioxidant enzyme activity, and soil enzymatic activities. These amendments significantly improved the tobacco leaf quality by limiting the proline accumulation (62.17 and 77.31%) and malondialdehyde content (35.33 and 41.91%) at the reefing and flowering stages, respectively. Soil treated with a combination of bio-organic fertilizer, farm manure, and compound fertilizer (B₄) showed an increased soil enzyme activities with acid phosphatase improving by 19.91%, urease by 40.00%, and catalase activity by 7.41%, which results in enhanced soil nutrient status compared with other treatments. Based on these findings, it can be concluded that combined application of organic amendments resulted in better growth, improved antioxidative defense system, and improved quality of tobacco by reducing the use of compound fertilizer (10%) and activating soil enzymatic attributes, thereby boosting the tobacco productivity in agricultural systems.