Nitrogen fertilizer influence on wheat yield and use efficiency under different environmental conditions

Managing N inputs in wheat production systems is an important issue in order to achieve maximum profitable production, and minimum negative environmental impact. The aim of this investigation carried out in dry land farming in the Vojvodina province (Serbia) was to estimate the effects of different N fertilization levels (0, 75, and 150 kg N ha(-1)) on some quantitative traits, rain-use efficiency (RUE), N agronomic efficiency (NAE), and N use efficiency (NUE) in two Serbian winter wheat (Triticum aestivum L.) cultivars 'Pobeda' and 'Renesansa'. 'Pobeda' had higher grain yield (4437 kg ha(-1)) and RUE (8.32 kg ha(-1) mm(-1)) than 'Renesansa' (4265 kg ha(-1) and 8 kg ha(-1) mm(-1), respectively). Grain yield (4652 kg ha(-1)) and NUE (31.46 kg kg(-1) N) were higher in the 2010-2011 season (favorable weather conditions) than in the 2011-2012 (4050 kg ha(-1) and 27.59 kg kg(-1) N, respectively). The highly significant effect on grain yield (4396 and 4494 kg ha(-1)), RUE (8.24 and 8.45 kg ha(-1) mm(-1)), NAE (3.11 and 2.21 kg kg(-1) N) and NUE (58.62 and 29.96 kg kg(-1) N) had levels of 75 and 150 kg N ha(-1). NAE and NUE declined at high N rates. Based on the results of this study, farmers should be advised that the use of large amounts of N increases production costs and reduce the economic benefits. The increase in wheat production is possible by selecting adapted genotypes with improved NUE