[Carbon sequestration efficiency of straw incorporation: Long-term dynamics, influencing factors and...

Straw returning is a key measure to increase soil carbon sequestration. We reviewed the critical processes of straw carbon sequestration, the long-term dynamics of carbon sequestration efficiency, influencing factors, and enhancement pathways. The short-term effects of straw returning include the increase in active organic carbon components such as dissolved organic carbon, particulate organic carbon, and microbial biomass carbon. The long-term effect is the accumulation of total organic carbon reserves. Soil carbon storage after straw returning follows a progressive saturation pattern, with lower initial soil organic carbon content allowing greater carbon storage potential and requiring more time to reach saturation. The efficiency of straw carbon sequestration is constrained by straw returning methods, straw characteristics (crop type, lignin content, straw size, and return quantity), as well as soil and climatic conditions. Enhancement pathways for straw carbon sequestration include optimizing straw return methods, water-saving irrigation, balanced fertilization, microbial inoculation, and diversified cropping systems. Future research should focus on long-term dynamic monitoring of straw carbon sequestration, coordinated optimization of agronomic measures, and adaptive management to climate change.