Optimizing spinach germination and quality with <i>Azotobacter</i> inoculation and synthetic nitrogen fertilization

Agricultural production is increasingly shifting toward more sustainable and environmentally friendly practices. These approaches are designed to enhance the quality and yield of crops and vegetables. Spinach is among the most widely consumed leafy vegetables globally, valued for its health-promoting nutritional values. A greenhouse experiment was conducted to evaluate the effects of Azotobacter vinelandii (AV) inoculation and urea application rates (0, 25, 50, 75, and 100 kg/ha) on spinach seed germination and yield quality, using a randomized complete block design (RCBD) with five replications. The co-application of AV and urea (&lt;50 kg/ha) significantly enhanced the key attributes examined in the study. AV inoculation enhanced seed germination energy, leaf dry biomass, total antioxidant activity (TAA), and potassium content. However, applying urea at rates exceeding 75 kg/ha had a negative impact on seed germination, yield, and quality. The integrated use of AV inoculum and urea provided sufficient nitrogen to the plants, thereby promoting growth and development. This study presents a sustainable and cost-effective approach for farmers to enhance vegetable quality and yield through conventional methods.