Comparative Analysis of Biofertilizers and Chemical Fertilizers on Yield Components and Nitrate Accumulation in Sante Potato Cultivar

Background: In the context of sustainable agriculture, reducing chemical fertilizer use is crucial to protect environmental and human health.This study aimed to evaluate the effects of various fertilizer regimes and tuber inoculation with beneficial bacteria on the quality traits of the potato cultivar Sant.Methods: A field experiment was conducted during the 2016-2017 growing seasons at the Agricultural Research Farm of Hamadan Islamic Azad University.Treatments included five fertilizer regimes: no fertilizer (control), 100% nitrogen (N), 66% N + 33% organic fertilizer, 33% N + 66% organic fertilizer, and 100% organic fertilizer.Further, tubers were inoculated with Azospirillum, Pseudomonas, or a combination of both.Results: In 2017, the lowest nitrate content (16.67 mg/kg) was observed with 33% N + 66% organic fertilizer treatment combined with Pseudomonas inoculation.The highest protein content (7.05%) was recorded under the 100% organic fertilizer treatment with dual bacterial inoculation.The highest starch content (19.76%) and protein yield (1861 kg/ha) were obtained in 2016 under combined fertilizer and bacterial treatments.Yield components improved with partial nitrogen replacement by organic fertilizer, particularly when Pseudomonas was applied.Conclusion: While biofertilizers alone may not fully replace chemical fertilizers, their integration with organic inputs can significantly enhance potato quality and yield while reducing nitrate accumulation.These findings support the adoption of integrated fertilization strategies as a viable approach toward more sustainable potato production systems.