Bacterial Diversity and Community in Response to Long-Term Nitrogen Fertilization Gradient in Citrus Orchard Soils

Citrus orchards receive increasing amounts of nitrogen fertilizer for the purpose optimal yields and good quality citrus fruits. Although effects increased on fruit trees have been reasonably well studied, few comparable studies examined impacts soil bacterial communities diversity, even though they play critical roles in orchard ecosystem functioning. In our study, Illumina MiSeq sequencing was used to investigate community structure diversity under 5-years long-term fertilization gradients (N0, N1, N2, N3, N4, N5) soils. The result showed that addition along N0 N3 gradient but decreased N5 gradient. increase rate altered composition by relative abundance Delta-proteobacteria, Nitrospirae, SBR1093, Latescibacteria decreasing Alpha-proteobacteria. Finally, regression analysis revealed Nitrosomonadales, Rhodobiaceae, Gemmatimonas, Variibacter exhibited a significant positive correlation with yield. study reasonable applied could improve