EFFECTS OF FERTILIZATION AND STRAW INCORPORATION ON BACTERIAL COMMUNITIES IN BLACK SOIL, NORTHEASTERN CHINA

The effects of three treatments including no fertilizer or straw returned to the field (CK), chemical fertilizer with straw not returned to the field (F) and no fertilizer with straw returned to the field (W) on the composition, diversity and structure of the soil bacterial community were examined. The results showed that a total of 1,833,232 reads and 25,843 operational taxonomic units (OTUs) were obtained through sequencing. The dominant bacteria of the black soil in the northeast (>10%) were Proteobacteria, Acidobacteria, Bacteroidetes, Chloroflexi and actinomycetes. The soil bacterial diversity was greatly improved, but fertilization had little effect on the soil bacterial diversity. A stratified clustering map showed that the soil bacterial community structures after W and F treatments were similar to one another at genus level, and the soil bacterial community structures after treatment with W and F were different from those after treatment with CK. The effect of fertilizer application on the composition, relative abundance and community structure of dominant groups of soil bacteria was greater than that of straw mulching, which significantly reduced the soil bacterial richness, whereas straw mulching significantly increased the soil bacterial diversity.