International Journal of Plant & Soil Science

The present investigation evaluated biogenically synthesised nanosulphur as a foliar nutrient source for improving soybean growth and yield during the Kharif season of 2023–24 at Dr Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra. Sulphur nanoparticles were synthesised under controlled laboratory conditions using sodium thiosulphate as the sulphur precursor and neem (Azadirachta indica) leaf extract as a reducing and stabilising agent. Analytical characterisation confirmed high purity, stability, nanoscale size and suitable morphological, structural, elemental and biomolecule-mediated surface characteristics. The field experiment was conducted in a randomised block design with six treatments and four replications. The treatments comprised the general recommended dose of fertilisers (GRDF; 30:60:30 kg N:P₂O₅:K₂O ha⁻¹), GRDF supplemented with foliar applications of 25, 50 or 75 ppm biogenically synthesised nanosulphur at 30 and 45 days after sowing, GRDF supplemented with 30 kg S ha⁻¹ through bentonite sulphur, and an absolute control. GRDF combined with 75 ppm nanosulphur significantly improved plant height, branches plant⁻¹, dry matter accumulation plant⁻¹, chlorophyll SPAD value, seed yield and stover yield. This treatment produced 2,551 kg ha⁻¹ seed yield and 3,342 kg ha⁻¹ stover yield and was statistically comparable with GRDF supplemented with 30 kg S ha⁻¹ through bentonite sulphur for most growth and yield attributes. Nodule number was not significantly affected by the sulphur treatments. These findings indicate that foliar application of 75 ppm biogenically synthesised nanosulphur can support soybean growth and yield under the conditions of this experiment.