The environmental drawbacks of chemical phosphate fertilizers have heightened interest in biofertilizers as sustainable alternatives. However, their efficacy is frequently genotype-dependent, a factor often neglected in broad recommendations. This study investigated the interaction between the phosphate-solubilizing biofertilizer Barvar 2® and different lentil (Lens culinaris Medik.) cultivars to develop a genotype-specific strategy for sustainable production. A field experiment was conducted in 2024 in semi-arid western Iran using a factorial randomized complete block design with three phosphate sources (control, Barvar 2®, and triple superphosphate) and three lentil cultivars (local Abdanan, Sasken, and Sepehr). Results revealed a significant Cultivar × Fertilizer interaction for most agronomic traits. The Sasken cultivar inoculated with Barvar 2® consistently outperformed others, yielding the highest plant height, branch number, pod number, and thousand-grain weight. This combination produced the maximum biological yield (154.66 g m⁻²) and grain yield (68 g m⁻²), matching or surpassing chemical fertilizer performance. Conversely, the local Abdanan cultivar showed the poorest response, especially under unfertilized conditions. In conclusion, Barvar 2® is not universally effective but demonstrates exceptional synergy with responsive modern cultivars like Sasken. These findings underscore the critical importance of genotype-specific nutrient management over generic fertilization approaches. The Sasken + Barvar 2® combination presents a viable and sustainable strategy for enhancing lentil productivity while reducing reliance on chemical phosphate fertilizers.
