Abstract: To investigate the effects of staged nitrogen （N） application combined with the nitrification inhibitor 3，4-dimethylpyrazole phosphate （DMPP） on nitrogen uptake， utilization， and yield of forage oat （Avena sativa L.）， a field experiment was conducted with seven N fertilizer treatments： no N application （CK）， conventional N application （105 kg·hm^-2， N₁₀₅； 210 kg·hm^-2， N₂₁₀； 300 kg·hm^-2， N₃₀₀）， reduced-staged optimized N application （168 kg·hm^-2， O₁₆₈）， and reduced-staged optimized N application combined with DMPP （O₁₆₈+D， O₁₄₄+D） The results showed that compared with conventional N application， the O₁₆₈+D treatment achieved the highest yield of 7412.13 kg·hm^-2， which was significantly higher than that of under conventional N application （P<0.05）. Compared to the N₂₁₀ treatment， the oat plant nitrogen uptake， nitrogen agronomic efficiency， and nitrogen use efficiency increased by 4.90%， 48.51%， and 6.44% in O₁₆₈+D treatment， respectively. Therefore， under the condition of Horqin aeolian sandy soil， the optimized treatment-combining reduced-staged application of N with DMPP can increase the yield and improve the N use efficiency of forage oat. These findings provide a theoretical basis for enhancing the yield of forage oat and optimizing N fertilizer application in the Horqin Sandy Land.

Key words: Forage oats, Nitrification inhibitor, Nitrogen fertilizer application rate, Nitrogen use efficiency, Yield

摘要： 为探讨分期施氮和添加硝化抑制剂（3，4-Dimethylpyrazole Phosphate，DMPP）对饲用燕麦（Avena sativa L.）氮素吸收利用和产量的影响，本研究以饲用燕麦为试验材料，设置7个处理：不施氮（CK）；常规施氮105 kg·hm^-2（N₁₀₅），210 kg·hm^-2（N₂₁₀）和300 kg·hm^-2（N₃₀₀）；减量优化施氮168 kg·hm^-2（O₁₆₈）；减量优化施氮配施DMPP（O₁₆₈+D、O₁₄₄+D），测定饲用燕麦氮肥利用特征及影响因素。结果表明，相较于常规施氮处理，O₁₆₈+D处理下的产量最高，为7412.13 kg·hm^-2，显著高于常规施氮处理（P<0.05），燕麦植株氮素吸收量、氮肥农学效率和氮肥利用率相比N₂₁₀处理分别提高了4.90%，48.51%和6.44%。因此，在科尔沁风沙土条件下，通过氮肥减量分期施用结合DMPP进行优化处理，能够起到增产和提高饲用燕麦氮肥利用率的作用，研究结果为科尔沁沙地饲用燕麦增产和氮肥合理施用提供了理论依据。

关键词: 饲用燕麦, 硝化抑制剂, 氮肥施用量, 氮肥利用率, 产量