【目的】在烟-稻复种连作系统中，探讨烟后作水稻茎鞘物质转运及其产量对减氮配施生物炭处理的响应，以期为复种连作土壤改良提供科学依据。【方法】以杂交水稻甬优1540为材料，常规施氮栽培为对照(T0)，在烤烟收获后全土层施用30 t/hm²生物炭的前提下，设置纯氮不减施(T1)、纯氮减施10%(T2)、纯氮减施20%(T3)和纯氮减施30%(T4)处理，分析了水稻产量变化与茎鞘同化物积累、转运的关系及其调控机制。【结果】结果表明，2年田间试验各处理产量均表现为T1>T2>T3>T0>T4，其中减氮10%~20%处理(T2和T3)与未减氮处理(T1)之间差异不显著，但均显著高于T0和T4，T2与T3处理2年平均实际产量分别比对照提高了13.94%和13.46%。收获指数方面，T2和T3处理均显著高于其他处理，各处理谷草比表现为T3>T2>T4>T1>T0。生物炭处理并适当减氮下抽穗期叶片净光合速率及SPAD值均显著高于对照。T1处理分蘖数峰值最高，但其分蘖成穗率却显著低于T2和T3处理。在茎鞘物质输出率和茎鞘物质转化率上，T3与T2处理差异不显著，但均显著高于其他处理；茎鞘非结构性碳水化合物(Non-Structural Carbohydrate，NSC)转运量、转运率及籽粒贡献率与茎鞘物质输出率和茎鞘物质转化率表现一致。茎鞘蔗糖相关酶活性分析表明，T3和T2处理水稻灌浆早中期α-淀粉酶、β-淀粉酶、蔗糖合成酶(SS)、蔗糖磷酸合成酶(SPS)活性均最高，但抽穗后20 d这些酶活性则以T1处理最高。【结论】生物炭可改善水稻灌浆期叶片光合性能，减施10%~20%氮肥有利于提高水稻抽穗期茎鞘蔗糖合成与转运酶活性，促进茎鞘物质的积累与转运，提高水稻收获指数，实现“减氮保产”的栽培目标。

【Objective】In the tobacco-rice multiple and continuous cropping system, the responses of the translocation of stem and sheath assimilates and the yield of rice were explored to lay a scientific basis for soil improvement. 【Method】The hybrid rice “Yongyou 1540” was used as the material, with conventional nitrogen application as the control (T0). Under the premise of applying 30 t/hm² biochar in the whole soil layer after the harvest of flue-cured tobacco, the relationships between rice yield and the accumulation and translocation of assimilates in stem and sheath and their regulatory mechanisms were analyzed by setting treatments of no reduction in nitrogen (T1), 10% reduction in nitrogen (T2), 20% reduction in nitrogen (T3), and 30% reduction in nitrogen (T4).【Result】The results revealed that the yield of treatments showed a trend of T1>T2>T3>T0>T4 in the 2-year field trial. The differences between the T2 and T3 treatments with 10%, 20% nitrogen reduction and the T1 treatment without nitrogen reduction were not significant, but they were all significantly higher than that of the T0 and T4 treatments. The average actual yield of T2 and T3 treatments increased by 13.94% and 13.46%, respectively compared with the control in 2 years. In terms of harvest index, T2 and T3 treatments were significantly higher than other treatments, and the ratio of grain to grass in each treatment was T3>T2>T4>T1>T0. The net photosynthetic rate and SPAD value of leaves at the heading stage under biochar treatment with appropriate nitrogen reduction were significantly higher than those of the control. The peak tiller number of T1 treatment was the highest, but the productive tiller rate was significantly lower than that under nitrogen reduction with biochar treatments. There was no significant difference between T3 and T2 treatments in the export percentage and translocation percentage of stem-sheath assimilates, but they were significantly higher than other treatments. The transport capacity, transport rate, and grain contribution rate of non-structural carbohydrate (NSC) in stems and sheathes were consistent with the export percentage and translocation percentage of stem-sheath assimilates. Analysis of sucrose-related enzyme activities in stem and sheath showed that the activities of α-Amylase, β-Amylase, sucrose synthase (SS), and sucrose phosphate synthase (SPS) in T3 and T2 treatments at pre- and mid-grain filling stages were the highest. However, these enzyme activities were highest in the T1 treatment at 20 days after heading.【Conclusion】The application of biochar can improve the photosynthetic performance of rice leaves during the grain filling period. Reducing the application of 10%, 20% nitrogen fertilizer was conducive to improving the activities of sucrose synthesis and transport enzymes in the stem and sheath at the heading stage, promoting the accumulation and translocation of stem sheath matter, improving the rice harvest index, and achieving the cultivation goal of “reducing nitrogen and maintaining yield”.