关键词: 小麦, ¹⁵N示踪, 缓释氮肥, 土壤调理剂, 氮累积转运, 产量

Abstract: To improve the nitrogen fertilizer use efficiency in wheat production，a two⁃factor split⁃plot field experiment was conducted from 2022 to 2024 using the ¹⁵N isotope tracing technique. The main factor was nitrogen fertilizer type，including conventional nitrogen fertilizer（X） and slow⁃release nitrogen fertilizer（Y）. The sub⁃factor was soil conditioner type，including no conditioner（A），biochar（B），zeolite（C），and vermiculite （D）. The effects of different nitrogen fertilizers and soil conditioners on wheat yield，nitrogen accumulation and translocation，and nitrogen utilization were analyzed. The results showed that the YB treatment exhibited significantly better performance in yield increase and improvement of nitrogen accumulation，translocation and utilization than all other treatments. Compared with the XA treatment，the wheat yield of YB was increased by 31.29%；the nitrogen accumulation amounts in stem and sheath，rachis and glume，leaves，and grains were increased by 54.54%，52.23%，42.51%，and 19.43%，respectively. This treatment optimized the source proportion of fertilizer nitrogen and soil nitrogen，resulting in a 38. 42% increase in total plant nitrogen accumulation. The uptake of fertilizer nitrogen was increased by 44.66%，while the residual amount and loss amount of fertilizer nitrogen were decreased by 4.95% and 56.61%，respectively. The nitrogen transport capacity，transport efficiency，transport contribution rate were increased by 26.63%，15.79%，and 19.16%，respectively. The nitrogen use efficiency，nitrogen uptake efficiency，and partial factor productivity of nitrogen fertilizer were increased by 27.12%，36.84%，and 26.78%，respectively.Correlation analysis indicated that each index had varying degrees of influence on wheat yield，total nitrogen accumulation，and nitrogen use efficiency.Principal component analysis verified that the combined application of slow⁃release nitrogen fertilizer and biochar was the optimal treatment. In conclusion，the combined application of slow⁃release nitrogen fertilizer and biochar could significantly promote nitrogen uptake，accumulation，translocation and distribution in wheat plants，reduce fertilizer nitrogen loss，and synergistically improve nitrogen fertilizer use efficiency and wheat yield. It is the optimal fertilization and soil improvement scheme to balance grain yield increase and efficient nitrogen fertilizer utilization under the experimental conditions.

Key words: Wheat, ¹⁵N tracing, Slow?release nitrogen fertilizer, Soil conditioner, Nitrogen accumulation and transport, Yield