Biochar‐Based Urea Enhances Yield and Quality of Lady's Finger ( Abelmoschus esculentus L.): A Pathway Towards Sustainable Nitrogen Management

Low nitrogen‐use efficiency (NUE) and excessive application of nitrogen fertilizers pose serious threats to sustainable agriculture, causing severe soil fertility depletion, environmental degradation, and economic losses. Biochar‐based nitrogen fertilizers (BBNFs) offer a promising strategy to enhance NUE through controlled nutrient release and improved soil quality. However, the effect of BBNFs on lady's finger ( Abelmoschus esculentus L.) production is still limited. Therefore, this study was conducted to evaluate the effects of BBNFs on the growth, yield, and nutritional quality of lady's finger. Seven treatments were employed, including conventional urea, biochar‐mixed urea (BMU), and biochar‐coated urea (BCU). Results demonstrated that BCU (T7) significantly ( p ≤ 0.05) outperformed all other treatments, producing the highest number of leaves, leaf area, plant height, photosynthetic rate, biomass accumulation, and pod yield (13.62 t ha −1 ), representing a 65.9% increase over conventional urea. BCU also achieved the greatest agronomic nitrogen‐use efficiency (24.27 g g −1 ), harvest index (55.41%), and cost‐income ratio (2.63). Nutritional quality traits, including TSS, ascorbic acid, total flavonoids, protein, etc., were also significantly enhanced under BCU. The findings highlight the potential of BCU as a sustainable fertilizer management strategy that improves yield, fruit quality, and economic returns in lady's finger, while providing actionable approaches to enhance NUE and mitigate environmental degradation.