Molecular characterization and fertilizer optimization in soybean to maximize productivity and minimize environmental impact

Climate change and deteriorating soil conditions have exacerbated water resource challenges, significantly limiting soybean yield. The molecular characterization and correlation analysis of germplasm elucidates its genetic potential, while productivity is contingent upon the essential macronutrients supplied in the form of NPK fertilizers. However, indiscriminate use of excessive NPK fertilizers, devoid of strategic optimization, compromises soil vitality and accelerates environmental damage. Under PEG-induced drought stress screening experiment, T2 showed slight reductions (5–45%) while T3 faced moderate losses (23–89%) and T4 displayed significant declines (43–90%) across all evaluated growth parameters such as SL, RL, FSW, FRW, DSW and DRW. SSR markers were employed to assess genetic diversity, with principal component analysis (PCA) accounting for up to 73.8% of the variation. The response surface statistical model predicts the optimal conditions, which include the application rates of nitrogen, phosphorus, and potassium (65, 40, and 20 kg/ha), while maintaining soil moisture levels between 100 and 150 mm. In a validation experiment, eleven out of forty-eight soybean accessions demonstrated productivity improvements, specifically SPS45, PGRB58, GP40032, GP40067, and GP40136, in comparison to control plants. This study illustrated that integration of molecular characterization with fertilizer optimization enhances sustainable soybean cultivation by boosting nutrient-use efficiency, thereby reducing fertilizer losses, and the overall environmental impact.