The field experiment was conducted in the Kharif season spanning 2022-23 to determine the most effective nutrient management practice via foliar application in Mungbean (Vigna radiata L.) in a guava (Psidium guajava L.) cv. Lalit based agri-horti system. The studies were conducted at Agroforestry Research Farm, Banaras Hindu University campus in Randomized Block Design (RBD) with ten treatments and three replications. The guava fruit orchard of size 7x7 m was established in 2007. The orchard had an average height of 5.85 m, canopy diameter of 5.60 m, stem girth of 0.97 cm and crown length of 4.93 m. Mungbean cv. Samrat, a short duration (60-65 days) and yellow mosaic virus resistant variety were used for the study. The plot size was 9 m2 (gross) and 4.80 m2 (net) with an inter-row spacing of 30 cm and an intra-row spacing of 10 cm. The seeds were sown at the rate of 15 kg ha-1. The plants were raised till 64 days and the treatments with different concentrations of recommended fertilizer foliar were given when most of the (80 %) pods turned brown. The results revealed that treatment T₁₀ in which recommended fertilizer dose (18:48:24 kg ha-1 N:P₂O₅: K₂O) along with foliar applications of Nano urea (4 mL L-1), 0.5 % ZnSO₄ and 0.2 % Boron at pre-flowering and pod development stages gave high yield. The plants subjected to this treatment showed significantly low mortality but increased plant height, branching, leaf production, yield and improved economic returns (gross return, net return and benefit-cost ratio). The second most effective treatment was T₉ in which recommended fertilizer dose was supplemented with 0.5 % ZnSO₄ and 0.2 % boron applied twice, at pre-flowering and pod development stages. Integrating optimized fertilization and foliar nutrient applications to enhance mungbean yield while maintaining sustainable practices in agri-horti systems.