基于宏基因组测序探究施肥对新增耕地土壤微生物群落结构和功能的影响OA

To clarify the effects of fertilization measures on the structure and function of soil microbial communities in newly reclaimed cropland,a 2-year continuous cropping experiment was conducted in such cropland.Four treatments were set up:no fertilization(CK),organic fertilizer(M),combined application of organic and inorganic fertilizers(MNPK),and combined application of organic and inorganic fertilizers with additional microbial inoculant(MNPKB).Metagenomic sequencing technology was used to systematically investigate the changes in the composition and function of soil microbial communities under different fertilization patterns.The results showed that bacteria dominated the soil microbial community in the newly reclaimed cropland,followed by archaea,eukaryotes,and viruses.Compared with the no-fertilization treatment(CK),fertilization treatments significantly reduced the relative abundance of eukaryotes and viruses in the soil.At the phylum and genus levels of bacteria and archaea,there were no significant differences in the types or relative abundance of the dominant phyla and genera.For eukaryota at the phylum level,the dominant phyla were consistent across all treatments,including Ascomycota(63.73％-86.89％),Mucoromycota(14.23％-16.88％),and Basidiomycota(2.83％-11.73％),but their relative abundances differed significantly.The dominant genera in the CK treatment were Clonostachys(10.32％),Fusarium(10.17％),and Hapsidospora(5.72％),while those in the fertilization treatments were Rhizopus(7.42％-8.24％),Glutinoglossum(5.65％-6.90％),and Aspergillus(5.32％-6.57％),indicating significant differences in both the types and relative abundances of dominant eukaryota genera between fertilized and unfertilized soils.Functional gene analysis revealed that the soil microbial community in the newly reclaimed cropland had 6 primary and 48 secondary functional metabolic pathways,with metabolic-related genes showing the highest abundance.Based on the KEGG database,significant differences were observed in eukaryota functional genes among treatments.Field capacity and soil pH were identified as key factors affecting the structure and function of microbial communities;moreover,field capacity was the main positive factor influencing crop yield,regardless of whether the analysis focused on bacteria,archaea,or fungi.Among all fertilization treatments,the combined application of organic and inorganic fertilizers with additional microbial inoculant(MNPKB)exhibited the optimal effects on soil physical structure and nutrient indicators,and significantly increased crop yield compared to the other fertilization treatments.