摘要 : Context or problem: Organic -inorganic fertilization has been proven to maintain sustainable rice production. However, the chemical nitrogen (N) fertilizer reduction and its underlying mechanisms have not been revealed under organ... 展开 Context or problem: Organic -inorganic fertilization has been proven to maintain sustainable rice production. However, the chemical nitrogen (N) fertilizer reduction and its underlying mechanisms have not been revealed under organic -inorganic fertilization. Objective or research question: The objective of this study was to quantify how organic -inorganic fertilization affected rice yield and the source -sink relationship during grain filling. Methods: A two-year field experiment was conducted during the rice growing seasons of 2021 and 2022, with two organic fertilizer levels (-M, 0 kg ha -1 and +M, 3000 kg ha -1), and five N rates (N0: 0 kg ha -1, N90: 90 kg ha -1, N180: 180 kg ha -1, N270: 270 kg ha -1, N360: 360 kg ha -1). Rice yield and yield components, agronomic N use efficiency (AE), leaf area index (LAI), chlorophyll content, and source -sink traits were examined. Results: Compared with -M treatment, organic -inorganic fertilization increased rice yield. Rice yield for N180 + M was comparable to that for N270 and N360 in two years, while AEtotal N significantly increased 22.29% compared to N360. LAI and SPAD value were also increased under organic -inorganic fertilization. The rice sink growth and source activity increased with the increase of N rate and organic fertilization. Compared with -M treatment, organic -inorganic fertilization showed higher sink growth and source capacity. Rice yield was sourcelimited under -M and +M treatments, while organic fertilizer application could increase the source/sink ratio. Meanwhile, we found that the source/sink ratio was significantly positively correlated with rice grain yield. Partial least squares path modeling (PLS-PM) showed that organic -inorganic fertilization optimized source -sink balance by increasing source capacity and sink growth, thereby increasing the rice yield. Conclusions: The high rice yield of organic -inorganic fertilizer over N fertilizer could be explained by its higher sink growth and source capacity. Considering comprehensively yield, AE, and source -sink balance, a combination of N rate of 180 kg ha -1 and organic fertilization of 3000 kg ha -1 was the optimal organic -inorganic fertilization management practice. Implications or significance: The study provides a scientific basis for chemical N reduction in rice production and contributes to the promotion of agriculture sustainable development. 收起