Nano-urea driven improvements in nitrogen efficiency and wheat productivity: trade-offs, synergies, and climate resilience pathways

Efficient nitrogen (N) management remains a major challenge in wheat production, where low N use efficiency (NUE) contributes to reduced yields and environmental degradation. Although nano-urea has emerged as a promising complements to conventional urea, its optimal dose and integration with basal N applications under field conditions remain insufficiently explored. This study evaluated eight N management strategies combining basal N levels with foliar applications of NPPL liquid nano-urea, NPPL powdered nano-urea, and IFFCO nano-urea in a randomized block design [(N 0 PK + 2 ml NPPL nano urea, N 0 PK + 4 ml NPPL nano urea, N 50 PK + 2 ml L −1 NPPL nano urea, N 50 PK + 4 ml L −1 NPPL nano urea, N 0 PK + 0.625 g L −1 NPPL powered nano urea, N 50 PK + 0.625 g L −1 NPPL powered nano urea, N 75 PK + 4 ml L −1 IFFCO nano urea and 100% Recommended Dose of Fertilizer (RDF), i.e., 150–60–50 kg N-P 2 O 5 -K 2 O/ha)]. The results indicated that the N 50 PK + 4 mL L −1 NPPL liquid nano-urea treatment produced wheat yield comparable to those obtained with N 75 PK + 4 mL L −1 IFFCO nano-urea. However, yield under N 50 PK + NPPL liquid nano-urea remained lower than the recommended dose of fertilizers (RDF), whereas N75PK + IFFCO nano-urea was statistically at par with the RDF. Biochemical assessments indicated that N 50 PK + 4 ml L −1 NPPL liquid nano-urea enhanced grain quality and improved NUE more effectively than other treatments, whereas RDF produced superior morphological and physiological traits leading to maximum yield. These findings suggest that while nano-urea can enhance NUE and reduce potential N losses, achieving yields equivalent to RDF may require optimized basal N levels. Overall, the study provides new insights into dose optimization and the complementary role of nano-urea in sustainable nitrogen management for wheat production in the Indo-Gangetic Plains.