Effects of over 30-year of different fertilization regimes on fungal community compositions in the black soils of northeast China

In this study, we investigated the effects of four long-term fertilization regimes that were performed over 30 years, namely, non-fertilization (NoF), chemical fertilization (CF), manure fertilization (M) and chemical fertilization plus manure (CFM), on a range of soil properties and fungal communities at three locations which located in the northern, middle and southern parts of the black soil region of northeast China. The fungal communities were primarily analyzed by Illumina MiSeq sequencing targeting fungal rRNA operon ITS1 region. The results showed that the fertilizers (organic or inorganic) generally increased the soil nutrient contents and fungal abundances. Principal coordinate analysis (PCoA) revealed that all fungal communities were separated into three groups according to their sampling locations, and the soil pH was the most influential factor in determining the total fungal communities across the three locations. Similar fertilization treatments had inconsistent influences on the fungal community compositions and the most influential soil factor in shaping fungal community structures varied among the three locations. Amending with inorganic fertilizers increased the relative abundances of potentially pathogenic fungi in the southern location, while the addition of manure suppressed possible pathogenic fungal growth and enhanced the growth of beneficial fungi in the three locations. Our findings highlighted that the influences of geographical separation along with fertilization regimes should be considered when examining the responses of fungal communities to fertilization regimes in agricultural management.