The benefits of green manure for soil organic carbon (SOC) are evident. However, given the growing sensitivity of soil inorganic carbon (SIC) to environmental changes, both SOC and SIC must be considered in soil carbon management. Therefore, we conducted a 9-year experiment on the Loess Plateau, using Soybean/Sorghum-Sudan as green manure to replace fallow, to analyze SOC and SIC temporal dynamics, sequestration rates and explored their relationships with crop residue carbon (C) and nitrogen (N) inputs, pH, and Ca2+, aiming to evaluate the potential of different green manure for enhancing soil C sequestration. Results showed Soybean provided 69.8 % of Sorghum-Sudan's C input but 2.3 times higher N input. In the 0-10 cm, the soil pH decreased by an average of 0.06, 0.13, and 0.09 units from an initial pH of 8.46 over 9 years for the Fallow, Soybean, and Sorghum-Sudan treatments, respectively. SOC content increased with the experimental years in the 0-20 cm, while SIC decreased. The SOC sequestration rates in the 0-40 cm were 188.7 and 327.9 kg ha- 1 yr- 1 for Soybean and Sorghum-Sudan, respectively, while SIC loss rates were 58.8 and 23.7 kg ha- 1 yr- 1, respectively. Overall, both Soybean and Sorghum-Sudan facilitated C sequestration, with Sorghum-Sudan being more effective than Soybean. The increase in SOC and the reduction in SIC were associated with C and N inputs, respectively, whereas SIC changes were not correlated with pH, likely due to the buffering effect of carbonates. In conclusion, Sorghum-Sudan is recommended as green manure for enhancing SOC sequestration and reducing SIC loss in calcareous soils. This provides practical guidance for optimizing green manure strategies and integrating SOC and SIC management in semi-arid regions.