Depth-dependent Influence of Biochar Application on the Abundance and Community Structure of Diazotrophic Under Sugarcane Growth

Abstract

Abstract Despite progress in understanding diazotrophic distribution in surface soils, few studies have investigated the distribution of diazotrophic in dipper soil layers. Here, we leveraged high-throughput sequencing (HTS) of nifH genes obtained to assess the influence of biochar amended soil (BC) and control (CK), and soil depths (0-20, 20-40 and 40-60 cm) on diazotrophic abundance and community structures, and soil biochemical properties. Although soil physio-chemical properties, enzymes activities, diazotrophic genera and enriched OTUs were significantly influenced across the entire soil profiles, our results also revealed that BC amended soil significantly increased cane stalk height and weight, soil NO3-, NH4+, OM, TC and AK, and enhanced diazotrophic genera in soil depth 0-20 cm compared to CK treatment. Soil TC, TN, OM and NH4+ were the major impact factors shifting diazotrophic community structures in soil depth 0-20 cm. Moreover, multivariate ANOVA analysis revealed that changes in majority of the soil parameters measured were associated with soil depth rather than fertilization. More diazotrophic genera were to a greater extent significantly and positively associated with many soil environmental variables especially in the surface soil 0-20 cm than diazotrophic phyla. Overall, these results were more pronounced in 0-20 cm soil depth in BC than CK treatment.