Optimized drip fertigation frequency improves yield and water-nitrogen use efficiency of winter wheat with different yield potentials in the Huang-Huai-Hai region
摘要
In order to investigate the best water and nitrogen cultivation measures for winter wheat under drip fertigation in the Huang-Huai-Hai region, two winter wheat cultivars were selected in this experiment: no irrigation throughout the growth period, with 120 kg·ha− 1 of nitrogen top-dressed at the jointing stage (W0); two irrigations (120 mm total, 60 mm each) at the jointing and anthesis stages, with 60 kg·ha− 1 nitrogen applied per irrigation (W2); and four irrigations (120 mm total, 30 mm each) at the jointing, booting, anthesis, and grain-filling stages, with 30 kg·ha− 1 nitrogen per irrigation (W4). Results showed that both cultivars performed best under the W4 treatment. This water-nitrogen frequency optimized pre- and post-anthesis water use, shaped an optimal leaf area index (LAI), delayed flag leaf senescence, increased biomass post-anthesis, and achieved the highest yield and water-nitrogen use efficiency. Yannong 999 outperformed Jimai 22 in these aspects, with a 9.1% higher yield. Compared with W2 and W0, grain yield under W4 increased by 7.6% and 31.1% for Jimai 22, and by 4.9% and 37.3% for Yannong 999, respectively. Similarly, nitrogen use efficiency (NUE) increased by 2.9% and 13.7% for Jimai 22, and by 1.9% and 15.9% for Yannong 999 while water use efficiency (WUE) improved by 12.0% and 15.7% for Jimai 22, and by 8.2% and 18.5% for Yannong 999, respectively. In summary, four drip fertigation frequencies at the jointing, booting, anthesis, and grain-filling stages constitute higher yield and resource-efficient strategy for drip-fertigated winter wheat in the Huang-Huai-Hai region.