Insight into the correlation between biochar amendment and shifts in bacterial community 4 years after a single incorporation in soybean- and maize-planted soils in northeastern China.

To date, there have been few reports examining the correlation between biochar treatments, crop species, and microbiome shifts. In this study, shifts in the soil bacterial community were investigated 4 years after a single incorporation of biochar in soils planted with soybeans and maize. Clear changes in the bacterial community composition and structure were detected in the soybean-planted soil amended with low-titer biochar (7.89 t/ha), whereas such changes in the maize-planted soil were not observed at the same biochar amendment rate, suggesting a more sensitive influence on the bacterial community in the soybean-planted soil than that in the maize-planted soil. Bacterial abundance in the maize-planted soil was reduced significantly with increasing biochar addition (15.78 and 47.34 t/ha), which was probably due to the inhibitory substances originating from biochar. Both the bacterial community and biomarkers in soil under biochar amendment varied with planted crops, bacterial communities responding differently to biochar amendment. All these results suggested that biochar might influence the bacterial community in maize- and soybean-growing soils under different mechanisms. Our findings should be valuable for an in-depth understanding of the potential mechanism of soil microbiome changes following biochar incorporation and for biochar application in agriculture.