Effect of irrigation regimes and nano-urea based nitrogen management on yield attributes, productivity, nutrient acquisition and use efficiency of wheat in Eastern Plateau region of India

Wheat (Triticum aestivum L.) production is vital for India's food security, with projections indicating a substantial 70-104 % increase in demand by 2050. However, Eastern Plateau regions face challenges of warmer climate leading to aberration in irrigation regimes (IRs) and nutrient, especially nitrogen (N) management resulting in lower productivity. Study revealed that IRs significantly influenced yield attributes viz., spikelets/spike and 1000-grain weight, with moisture stress during grain filling stages adversely impacting grain development, resulted in 29 % yield reduction. The 100 % recommended dose of nitrogen (RDN) resulted in significantly superior yield attributes; surpassing nano-urea based nitrogen application. The grain yield with 100 % RDN leading with the highest yield and grain N content of 7.0 and 14.5 % more compared to nano-urea based 50 % RDN+2 NUS (nano-urea spray) treatment respectively. Interaction effect of 3-irrigation regimes with 100 % RDN on grain yield was significantly superior over NUS nullifying the synergistic effect of NUS with IRs. However, 50 % RDN+2 NUS reported significantly (p=0.05) superior N content (0.42 %) and N uptake (31.30 kg/ha) in straw. Additionally, five irrigations exhibited significantly higher grain and total N uptake by 30.9 and 25.78 % compared to two irrigations, respectively. Apparent nitrogen recovery and agronomic nitrogen use efficiency were the highest in 50 % RDN+2 NUS due to better N acquisition and less amount of N application through NUS. Thus 3-irrigation regimes and 100 % RDN can be recommended as an agronomic management practice for maximising wheat productivity in Eastern Plateau region of India.