关键词: 冬小麦, 氮肥减施, 腐植酸肥料, 产量, 氮素利用效率, 氮积累量, 黄褐土

Abstract: Based on a 3‑year field experiment，this study reduced nitrogen application by 20% compared with the conventional nitrogen application rate，combined with the application of slow/controlled‑release fertilizer and humic acid fertilizer. Five treatments were designed，including no application of nitrogen fertilizer（T1），conventional nitrogen application rate（T2），reducing nitrogen by 20%（T3），reducing nitrogen by 20% combined with slow/controlled‑release fertilizer（T4），and reducing nitrogen by 20% combined with humic acid fertilizer（T5）. The effects of different treatments on dry weight，nitrogen content and accumulation of aboveground part，grain yield，nitrogen use efficiency，and soil nutrient content were studied，so as to clarify the synergistic effects and suitable application conditions of these fertilizers under nitrogen reduction，and provide a scientific basis for enhancing soil fertility and ensuring sustainable development in yellow‑cinnamon soil farmland.The results showed that，compared with T1 treatment，in 3 a T2—T5 treatments generally significantly increased dry weight，nitrogen content and accumulation of aboveground part，grain yield of winter wheat，and soil nutrient content at mature stage.Compared with T2 treatment，in 3 a T3 treatment showed no significant difference in dry weight，nitrogen content and accumulation of aboveground part，and grain yield of winter wheat at mature stage；T4 treatment increased dry weight of aboveground part，grain nitrogen content，nitrogen accumulation of aboveground part，and grain yield at mature stage，however，there was no significant difference；T5 treatment significantly increased dry weight of aboveground part，grain nitrogen content，nitrogen accumulation of aboveground part，and grain yield at mature stage by 7.90%—12.78%，4.38%—7.67%，14.59%—22.33%，and 5.78%—8.73% respectively.Compared with T2 treatment，T3 treatment had no significant difference in nitrogen use efficiency；nitrogen use efficiency，agronomic use efficiency of nitrogen fertilizer，and partial factor productivity of nitrogen fertilizer significantly increased by 37.10%—43.19%，23.39%—29.97%，and 24.77%—26.41% under T4 treatment，and 75.88%—93.25%，60.49%—71.80%，and 32.19%—35.88% under T5 treatment，respectively.Regarding soil nutrients，in 3 a T3 and T4 treatments showed no significant difference in soil organic matter and available nitrogen contents compared with T2 treatment，while T5 treatment increased soil organic matter and available nitrogen contents by 5.32%—9.90% and 1.80%—5.52%，respectively.There were significant positive correlations between yield，nitrogen use efficiency and straw nitrogen content，aboveground nitrogen accumulation，and effective spike number at mature stage.In conclusion，the comprehensive performance order of different treatments is T5>T4>T2>T3>T1；compared with conventional nitrogen application rate，nitrogen reduction combined with slow/controlled‑release fertilizer significantly enhances nitrogen use efficiency；reducing nitrogen by 20% combined with humic acid fertilizer significantly increases dry weight and nitrogen accumulation of aboveground part of winter wheat，promotes nitrogen use，and improves grain yield.

Key words: Winter wheat, Nitrogen reduction, Humic acid fertilizer, Grain yield, Nitrogen use efficiency, Nitrogen accumulation, Yellow?cinnamon soil