Journal of Experimental Agriculture International

Aims: To assess the impact of nano-fertilization of nitrogen and sulphur on the growth, yield attributes, productivity, quality, nutrient uptake, post harvest soil nutrient status and economics of sunflower grown in clay loam soil.

Study Design: Randomized block design.

Place and Duration of Study: The field experiments were conducted during the kharif (July – October, 2024) and rabi (January - April, 2025) seasons at the Experimental Farm, Department of Agronomy, Faculty of Agriculture, Annamalai University, Annamalai Nagar.

Methodology: The experimental methodology employed was randomized block design incorporating eleven treatment combinations, with three replications. The treatments comprised different combinations of nitrogen (30, 45, 60 and 90 kg ha^-1) application through urea and nano urea and sulphur (45 kg ha^-1) application through gypsum.

Results: Among the treatments imposed, T₁₁ (45 kg N ha^-1 through urea + 45 kg N ha^-1 through nano urea + 45 kg S ha^-1 through gypsum) recorded the highest growth and yield attributes, seed yield (2722 kg ha^-1) and stalk yield (4828 kg ha^-1) and quality parameters in both crop seasons. This treatment also showed significantly greater uptake of N, P, K, and S by the crop in both crop seasons. With respect to soil nutrient status after harvest, T₅ recorded the highest available nitrogen, T₃ showed the maximum available phosphorus and potassium, while the highest available sulphur was observed in T₈ in both crop seasons. With regard to economic returns, T₁₁ recorded the highest net return and benefit cost ratio in both crop seasons.

Conclusion: The findings indicate that integrated application of conventional and nano-fertilized nitrogen, along with sulphur, enhances sunflower performance and improves nutrient uptake and soil fertility under heavy textured soils.