Abstract: The organic alternative, with its higher carbon sequestration and carbon sink potential, has always been a research hotspot. However, the soil type and climate characteristics have a significant impact on the carbon sequestration and cooling effects of the organic alternative. There is still a lack of targeted research on the optimal substitution ratio that can balance crop yield and emission reduction effects in typical soil areas. Based on this, this study took lime concretion black soil as the research object and set up control (CK), pure fertilizer (OPT), and different organic (chicken manure) substitution (1/4M, 1/2M, 3/4M, and M) experiments for two years of soil carbon sequestration. GHG emissions were monitored in the wheat season of the second year. The results showed that the soil organic carbon in the lime concretion black soil cropland increased significantly with the increase of the organic substitution ratio, but the carbon sequestration efficiency (SOCSR) decreased; the key greenhouse gas N₂O emissions showed different trends, with an increase followed by a decrease as the substitution rate increased; especially the N₂O emissions of the 1/4M treatment were the highest, followed by the OPT treatment and the 1/2M treatment, while the N₂O emissions of the CK and M treatments were the lowest; except for the 1/4M treatment, the CH₄ emissions of the other treatments were not significantly different. Combining the GHGs and soil carbon sequestration efficiency (SOCSR), the net greenhouse gas potential (field-GWP) of the high-organic-substitution cropland was - 4881.6 kg CO₂_eq ha^-1, which was significantly lower than the other treatments, while the field-GWP of the 1/2M treatment was the highest, reaching -1411.4 kg CO₂_eq ha^-1, which was significantly higher than the other treatments (excluding CK), and the field-GWP increased first and then decreased as the substitution rate increased. In different treatments, the emissions of N₂O and CH₄ from basal fertilization of wheat were significantly higher than those from topdressing fertilization, with N₂O emissions accounting for 59.1-67.3% of the total emissions and CH₄ emissions accounting for 61.9-75.0 % of the total emissions. Comparing the yields of different treatments, it was found that the yield of the 1/2M treatment was the highest, followed by the 1/4M treatment, then the 3/4M and OPT treatments, while the yield of the full replacement (M) treatment was the lowest. Considering the wheat yield and field-GWP, this study concludes that 50% chicken manure replacement can maintain wheat yield in lime concretion black soil while achieving a significant carbon sequestration and emission reduction effect, making it the optimal replacement ratio for the comprehensive economic and ecological benefits of wheat production in lime concretion black soil.