Increased soil organic carbon response to fertilization is associated with increasing microbial carbon use efficiency: Data synthesis

Microbial carbon use efficiency (CUE) is a key parameter for soil organic carbon (SOC) cycling. However, there is still lack of evidence for linkages between shifts in SOC stocks and altered microbial CUE under fertilization. Here, we conducted a meta-analysis to explore the effects of fertilization on microbial CUE and its relationships with SOC sequestration. We found that inorganic and combined inorganic-organic fertilization increased microbial CUE by 6.8% and 9.7%, respectively. These two types of fertilizer also increased SOC contents by 4.1% and 51.7%, respectively. Inorganic and combined inorganic-organic fertilization-induced increase in SOC content was positively associated with increased microbial CUE. Our result provided overwhelming evidence that the increase of microbial CUE induced by inorganic and combined inorganic-organic fertilization exerts important effect on SOC sequestration.