Soil organic carbon accumulation mechanisms in soil amended with maize straw and its biochar: entombing effect or biochemical protection?

Gaining insight into soil C cycling process from a viewpoint of microbiology is crucial for optimizing soil management strategies that would significantly alter soil microbial community and ultimately facilitating soil C sequestration. Although a lot of studies have recognized that microbial community characteristics such as microbial biomass, diversity, and composition in soil play an important role in controlling C cycling the findings on the interrelations between SOC and microbial community characteristics have been variable.This study performed a nine-year field experiment involving four treatments: NPK (mineral nitrogen, phosphorus, and potassium fertilizers), NPKS (NPK plus maize straw), NPKB (NPK plus maize straw biochar), and CK (no fertilizer) in a Mollisol. Understanding the mechanism of the relationship between soil microbial traits and SOC under different treatments, and providing data support and theoretical basis for organic carbon sequestration and soil fertility maintenance.