Abstract:

To clarify the optimal nitrogen fertilizer application which could simultaneously achieve high grain yield and high nitrogen use efficiency (NUE), the two winter wheat cultivars with strong gluten, ‘Jimai 20’ and ‘Zhouyuan 9369’, were used as materials. Five nitrogen levels included 0, 120, 180, 240, 300 kg N/hm ² were set. The dry matter accumulation and nitrogen content were measured through drying method and Kjeldahl method, and the relevant NUE indices were calculated subsequently. The results showed that with the increase of the nitrogen input, the yield increased first and then declined. ‘Jimai 20’ had the highest yield at N180 (7.28 t/hm ²) and N240 (7.26 t/hm ²), mainly due to the balanced yield components and higher dry matter accumulation (averaged at 18.54 t/hm ²). While ‘Zhouyuan 9369’ reached the highest yield (7.75 t/hm ²) at N180, mainly resulting from higher spikes per unit area (970.65×10 ⁴/hm ²), kernels per spike (30.83 kernels/spike), dry matter accumulation (20.77 t/hm ²) and harvest index (37.33%). Although the PFP_N markedly reduced along with the improved nitrogen level, the RE_N, AE_N and PE_N reached the highest value (62.67%, 5.71 kg/kg, 9.11 kg/kg for ‘Jimai 20’ and 63.65%, 7.33 kg/kg, 11.55 kg/kg for ‘Zhouyuan 9369’, respectively) under the condition of N180 level. In terms of the grain yield and NUE, the suitable nitrogen level which could simultaneously achieve high grain yield and high NUE is 180 kg N/hm ² in the region.

Key words: winter wheat with strong gluten, grain yield, nitrogen use efficiency, nitrogen level, coordination in yield and NUE