Vol. 7, Issue 7, Part A (2025)

Nitrogen is a vital nutrient that often limits crop productivity, making its efficient use crucial for agricultural sustainability. Nitrogen Use Efficiency (NUE) is a key metric that gauges a crop ability to absorb and utilize applied nitrogen. Effective nitrogen uptake and utilization are essential for maximizing crop yields while reducing environmental footprint. A field experiment titled "Evaluating the Impact of Conventional Urea and Nano Urea on Nitrogen Uptake and Nitrogen Use Efficiency of Tomato (Lycopersicon esculentum)" was conducted at the University of Horticultural Sciences, Bagalkot, during 2022-23. The study used a randomized complete block design (RCBD) with 12 treatments, replicated three times, and evaluated different nitrogen levels (100%, 75%, and 50%) applied through urea and nano urea (2 ml L^-1). The results showed that the treatment receiving 100% recommended dose of nitrogen (RDN) through 50% basal dose of urea and foliar application of nano urea at 30 and 45 days after transplanting (DAT) recorded the highest nitrogen content in leaves (3.33%) and fruits (0.36%), as well as higher nitrogen uptake (136.04 kg ha^-1) thereby increased the dry matter yield (3687.19 kg ha^-1). Moreover, the treatments receiving two sprays of nano urea showed significantly higher NUE (up to 149.52%) compared to conventional urea treatments (48.44%). Nano urea improves nitrogen management in tomato cultivation, reducing losses and promoting sustainability. However, careful consideration of soil health is crucial. Excessive nitrogen uptake may indicate soil mining and degradation. Judicious application and long-term soil fertility management are essential.