Nitrogen use efficiency in modern wheat cultivars affected by sowing dates

To enhance wheat productivity through advancements in crop production technology and breeding methodology, it is necessary to improve our understanding of the physiological processes associated with biomass accumulation, nitrogen uptake and nitrogen use efficiency. Therefore, a field trial with six winter wheat cultivars grown under conditions of four different sowing dates during two growing seasons was conducted to quantify the influence of cultivars and sowing date on variation in nitrogen use efficiency traits, biomass accumulation and nitrogen uptake, and their role in grain yield and nitrogen yield determination. Results showed that delaying sowing from October to November reduced grain yield by 1.49 t ha −1 on average per sowing date, and also caused a reduction of 14.6 and 14.3 kg ha −1 in nitrogen uptake at anthesis and maturity, respectively. Late sowing negatively impacted both grain yield and nitrogen grain yield in winter wheat cultivars, which was attributed to changes in biomass accumulation and nitrogen uptake at anthesis and maturity, as well as a decrease in nitrogen use efficiency and nitrogen uptake efficiency. The decrease in nitrogen use efficiency under late sowing was primarily due to a decrease in nitrogen uptake efficiency, as the increase in nitrogen utilization efficiency could not compensate for the nitrogen uptake efficiency decrease. The study findings suggest that midearly cultivars produced the highest average grain under different sowing conditions, mainly due to greater biomass accumulation during the pre-anthesis period, which provided additional nitrogen storage capacity. Therefore, under conditions of the Pannonian Plain wheat producers should be focused on the medium early cultivars characterized by increased pre-anthesis biomass accumulation.