Soil organic carbon (SOC) sequestration is well known as one of effective strategies for mitigating atmospheric greenhouse effect and sustainable development of global agriculture. Chinese semiarid Loess Plateau accounts for one-third of the arable land in China and provides food for more than 100 million people at present, therefore, fertilization and organic amendment are the crucial management strategies in Loess Plateau accounts for sustainable farming systems. However, long-term reliance on chemical fertilizers has gradually led to a decline in soil quality and soil organic matter (SOM) depletion. As the key driver of multiple biogeochemical processes, soil microbial communities can not only regulate soil health but also facilitate carbon sequestration in intensive agriculture.
The objective of this dissertation was to evaluate the long-term impact of fertilization management on soil physicochemical characteristics, SOC storage and the contribution of microbial community activities to SOC sequestration. In this study, we performed an 27-year field experiment with four fertilization treatments (CK: no fertilization management; NP: inorganic fertilizers application alone; NPS: inorganic fertilization plus the incorporation of maize straw; NPM: inorganic fertilization plus the incorporation of composted cow manure), and an incubation experiment (300 days) of classified aggregates (> 5 mm, 2–5 mm, 1–2 mm, 0.25–1 mm or 0.25 mm), but not in micro-aggregates ( 2 mm aggregates, while G+ bacteria were more important in