Trends in nitrogen use efficiency in a historical set of wheat cultivars in Serbia

Optimization of nitrogen (N) fertilizer use is a crucial factor for achieving high wheat yields while simultaneously improving the economic efficiency of production and reducing negative environmental impacts. The aim of this study was to determine the effect of two nitrogen fertilization levels on nitrogen use efficiency (NUE) and its components: nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE) in wheat varieties developed between 1930 and 2015. The research was conducted at the experimental field of the Institute of Field and Vegetable Crops, Rimski Šančevi, Serbia on haplic chernozem (Aric). The results showed that analyzed traits (NUE, NUpE and NUtE) were significantly affected by variety, fertilization and their interaction. Fertilization had the greatest effect on the variability of the examined traits. Application of N resulted in a NUE of 49.1 kg grain / kg available N in soil per ha, while in the control treatment it reached 81.6 kg grain / kg available N in soil per ha. The lowest values of the analyzed traits in both treatments were observed in the oldest cultivar Banatka, while modern cultivars showed higher values. Under the control treatment without N application, the mean NUpE increased by 0.42 N in biomass / kg N available in soil. The cultivar Simonida had the highest NUtE in the control treatment, while nitrogen application it resulted in a 15 kg grain / kg N in biomass lower value. A positive linear relationship was established between the year of variety release and all three investigated traits, particularly under the control treatment. These results indicates that modern cultivars demonstrate improved NUE, NUpE and NUtE under conditions of low nitrogen availability compared with older cultivars.