Nitrogen uptake and water consumption for achieving high yield of winter wheat upon nitrogen addition at different doses

Nitrogen nutrition is a critical determinant of agricultural productivity. Field experiments were conducted to investigate the effects of different nitrogen application rates on the growth, development, nitrogen absorption, yield, and protein content of winter wheat, with the aim of determining the optimal nitrogen fertilization regime for high yield. The experiment included seven nitrogen levels: 0 (N0), 90 (N90), 180 (N180), 210 (N210), 240 (N240), 270 (N270), and 300 (N300) kg ha⁻¹. Results demonstrated that nitrogen application significantly improved key growth parameters. The N210 and N240 treatments were particularly effective, promoting water consumption during the growth period, increasing the number of tillers at each growth stage, and enhancing overall nitrogen accumulation, which ultimately led to higher yield. Soil water consumption and water use efficiency (WUE) during the growth period were highest in the N210 and N240 treatments, respectively. Regarding yield components, the number of spikes, grains per ear, 1000-grain weight, and final grain yield were all superior in the N210 and N240 treatments compared to other levels. While the number of spike grains was highest under N240, it was not significantly different from N210. In contrast, the N300 treatment showed a significant reduction in spike grains compared to the N90 and N270 treatments. In conclusion, the application of nitrogen at rates of 210 kg ha^-1 and 240 kg ha^-1 optimizes yield components by promoting productive water consumption, tillering, and nitrogen accumulation, thereby achieving the highest grain yield in winter wheat.