【摘要】 为探明油菜秸秆还田条件下，棉花对油菜源和化肥源氮素吸收利用的差异，以湘FZ031为试验材料，于2022—2023年在湖南省常德市开展大田微区试验，采用氮同位素(¹⁵N)示踪技术，设置单施标记尿素(FN^15N)、标记尿素和秸秆还田普通油菜(FN^15N+RS^14N)、单秸秆还田标记油菜(RS^15N)、普通尿素和秸秆还田标记油菜(FN^14N+RS^15N)、不施氮对照（Untreated）5个处理，研究其对棉花各器官氮素来源于肥料氮的比例（Ndff）、¹⁵N回收率、¹⁵N肥料利用率和籽棉产量的影响。结果表明，两年间，FN^15N+RS^14N处理下各器官氮素来源于肥料氮的比例（Ndff）、¹⁵N回收率、¹⁵N肥料利用率分别较FN^15N处理提高4.80和4.78、5.56和5.24、0.78和0.33个百分点；FN^14N+RS^15N处理棉株各器官氮素来源于肥料氮的比例、¹⁵N回收率、¹⁵N肥料利用率分别较RS^15N处理降低5.15和4.67、30.25和24.92、40.05和42.94个百分点。2022和2023年的籽棉产量分别在FN^14N+RS^15N和FN^15N+RS^14N处理下最高。本研究初步说明油菜秸秆还田与化肥氮配施可以促进棉花对肥料氮的吸收，进而提高肥料氮的利用率。在不超过常规施氮量(180 kg·hm^-2)的条件下，棉花群体来源于油菜秸秆氮的比例为1.41%～7.31%；在油菜秸秆还田量不超过60 000 kg·hm^-2的条件下，棉花群体来源于肥料氮的比例为34.10%～40.94%。本研究为油菜秸秆利用和棉田的优化施肥提供了科学依据。更多还原

【Abstract】 To investigate the differences in nitrogen absorption and utilization by cotton from sources of rape straw and chemical fertilizer under rape straw incorporation, field micro-plot experiments were conducted using Xiang FZ031 as the test material in Changde City, Hunan Province, from 2022 to 2023. Nitrogen isotope(¹⁵N) tracer technique was used to set up five treatments: single application of labeled urea application(FN^15N), labeled urea and common rape straw returning(FN^15N+RS^14N), single application of labeled rape straw returning(RS^15N), common urea and labeled rape straw returning(FN^14N+RS^15N), no nitrogen application（Untreated）. The treatments were studied for the effects on the proportion of nitrogen derived from fertilizer nitrogen（Ndff） in various cotton organs, ¹⁵N recovery rate, ¹⁵N fertilizer use efficiency, and seed cotton yield. The results showed that during the two years, the Ndff, ¹⁵N recovery rate and ¹⁵N fertilizer utilization rate of cotton population under the FN^15N+RS^14N increased by 4. 80 and 4. 78, 5. 56 and 5. 24, 0. 78 and 0. 33 percentage points compared to the FN^15N, respectively. In contrast, the Ndff, ¹⁵N recovery rate and ¹⁵N fertilizer utilization rate of cotton population in the FN^14N+RS^15N increased by 5. 15 and 4. 67, 30. 25 and 24. 92, 40. 05 and 42. 94 percentage points compared to the RS^15N treatment, respectively. The highest seed cotton yields in 2022 and 2023 were observed under FN^14N+RS^15N and FN^15N+RS^14N, respectively. This study preliminary demonstrated that the combined application of rape straw and chemical fertilizer could enhance the absorption of fertilizer nitrogen by cotton, thereby improving the utilization efficiency of fertilizer nitrogen. Under the condition of not exceeding the conventional nitrogen rate(180 kg·hm^-2), the proportion of nitrogen derived from rape straw in the cotton population ranged from 1. 41% to 7. 31%. When the amount of rape straw incorporated did not exceed 60 000 kg·hm^-2, the proportion of nitrogen derived from fertilizer in the cotton population ranged from 34. 10% to 40. 94%. This study provide a scientific basis for the utilization of rapeseed straw and optimized fertilization in cotton fields.更多还原