Vegetative Growth Response of Spinach (Spinacia Oleracea L.) to the Transition from Conventional to Nano Urea

Spinach is a nutrient rich leafy vegetable with high nitrogen demand. Its growth and productivity are strongly influenced by the availability of nitrogen. This study evaluated the effect of foliar-applied nano urea on the vegetative growth, chlorophyll content, and soil nutrient status of spinach in Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh. The pot experiment was conducted in open-field conditions during the Rabi season, from mid-February to March 2025, using a completely randomized design (CRD) with six treatments and three replications. Treatments included T0 = Control (only soil), T1 = 100% RDF, T2 = Only Nano Urea (4 times) + 100% RDF (without Urea), T3 = 4 Times Nano Urea + 50% RDF (No Urea), T4 = 2 Times Nano Urea + 50% RDF, and T5 = No Nano Urea + No Urea + 100% Rest RDF. The results demonstrated that nano-urea treatments, especially the T3 treatment, significantly enhanced vegetative growth, such as plant height (12.81 cm and 17.47 cm at 30 and 45 DAS), number of leaves per plant (4.67 and 6.67 at 30 and 45 DAS), root length (6.90 cm), shoot length (17.47 cm), fresh plant weight (64.31 g), and chlorophyll content like chlorophyll a (11.22 mg g-1 FW), chlorophyll b (3.06 mg g-1 FW), and carotenoid (2.67 mg g-1 FW) compared to conventional fertilizer treatments. Soil nutrient analysis revealed improved availability of N, P, K, and S under nano-fertilizer treatments. The study highlights the potential of nano-urea to improve nitrogen use efficiency, enhance growth, and optimize soil fertility in spinach cultivation, suggesting its suitability as a sustainable nutrient management strategy.