Effects of nanomaterials on soil microbial community

Application of nanotechnology in agriculture has expanded to improve crop production. However, limited information concerning its effect on the indigenous soil microflora still remains. This study was conducted to assess the effects of nanofertilizer (FertiGroe N) and nano-plant hormone (HormoGroe Auxin) on the chemical properties and microbial community of Lipa clay loam (CL) and Sariaya sandy loam (SL) soils over 35 days incubation period in the laboratory. The bacterial and fungal communities were evaluated through amplicon sequencing analysis within the 16S and ITS regions, respectively. FertiGroe N significantly decreased soil pH relative to the control. No significant changes in total N and available P were observed in the FertiGroe N amended soils. A significant increase in exchangeable K was observed only in Lipa CL. HormoGroe Auxin had no significant effect on the soil chemical properties. The amplicon sequencing analysis showed that soil bacterial and fungal communities were not significantly affected by FertiGroe N application in both soils. On the other hand, HormoGroe Auxin amendment decreased the bacterial community only in Sariaya SL after 35 days of incubation. Moreover, the results showed that the microbial composition of bacteria and fungi was similar in Lipa CL and Sariaya SL. The relative abundance of bacteria at class level was dominated by Alphaproteobacteria, Actinobacteria and Acidobacteriia while fungi were dominated by Sordariomycetes, Mortierellomycetes and Agaricomycetes. Pearson correlation analysis showed that several bacterial and fungal community were correlated positively or negatively with soil pH. Results showed that FertiGroeTM N can be safely used in crop production. HormoGroe Auxin may be used mainly for vegetative propagation.