Nitrogen Accumulation, Use Efficiency, and Productivity of Wheat ( <i>Triticum aestivum</i> L.) as Influenced by Different Rates of Nitrogen in Lalitpur, Nepal

Appropriate application of nitrogen (N) not only increases wheat production but also results in optimum N use efficiency (NUE). An experiment was conducted to determine the N concentration, uptake, use efficiency, and performance of wheat in response to N fertility levels at Khumaltar, Lalitpur, Nepal, during 2019/20 and 2020/21. The experiment involved 7 treatments; 6 levels of N (0, 50, 75, 100, 125, and 150 kg ha −1 ) with application of P 2 O 5 :K 2 O in 50:50 kg ha −1 , and zero plot (no fertilizer application), which was laid out in randomized complete block design and replicated three times. The varying N had a significant influence on grain yield, N concentration, its uptake, NUE, and the economics of wheat production. Two years of pooled grain yield showed significantly ( p ≤ 0.001) higher grain yield (6.52 Mg ha −1 ) with a B: C ratio of 2.6, observed from the application of 150 kg N ha −1 , which was at par with the use of N @ 125 kg ha −1 (6.32 Mg ha −1 ). The 2‐year mean N concentration in grain and straw of wheat was 13.98 and 3.49 g kg −1 , respectively. The data revealed that 4.9 Mg ha −1 grain yield plus 5.56 Mg ha −1 dry straw yield removed 81.7 kg N ha −1 . Likewise, the N partition in wheat grain and straw was 75% and 25% respectively. The mean partial factor productivity, internal efficiency, physiological efficiency, recovery efficiency, and agronomic efficiency of N in wheat were found to be 61.8 kg kg −1 , 59.1 kg kg −1 , 53.1 kg kg −1 , 45.0%, and 22.5 kg kg −1 , respectively. N was a limiting nutrient as added N fertilizer had a considerable impact on wheat production and the use of 125 kg N ha −1 was recommended under similar soil properties and ecology.