Objective Effects of NPK contents and ecological stoichiometric ratios in soil on the fungal community at honey tangerine orchards were studied.

Method Contents and stoichiometric ratios of NPK in the soil sampled from three major production areas, i.e., Caijiayang, Duanjiang, and Fengyang, in Huangyan District, Taizhou, Zhejiang were analyzed and structures of the fungal communities determined using high-throughput sequencing of the ITS1 region. Correlations between the two categories of data were elucidated using redundancy analysis (RDA) and correlation analysis.

Result Among the three sampling sites, Duanjiang had the significantly lowest contents of total nitrogen (TN), available nitrogen (AN), and available potassium (AK) (P＜0.05), and Fengyang the lowest available phosphorus (AP). Duanjiang was also significantly lower on TN/TP and TN/TK ratios (P＜0.05), while Caijiayang significantly less on fungal α-diversity (P＜0.05) than the other areas. The principal coordinates analysis (PCoA) revealed a significantly differentiated fungal community structure at Caijiayang. The RDA indicated that TN and TN/TK were the critical drivers of the fungal community structure. TN positively correlated with the abundance of beneficial genera such as Saitozyma and Trichoderma but negatively with that of pathogenic genus Fusarium.

Conclusion TN and TN/TK in soil appeared to be the crucial indicators reflecting the regulation of fungal community at the honey tangerine orchards in Huangyan. Consequently, proper managing on them would help to maintain an ecologically healthy plantation in the area.