Abstract: High-throughput sequencing technology was used to investigate the effects of rice straw, chicken manure compost, cow manure compost, and vermicompost on soil bacterial community structure with 20 years continuous tomato cropping. Meanwhile, soil chemical properties were measured to quantify their effects on the variation of bacterial community structure, to provide theoretical basis for scientific application of fertilizers in tomato cultivation in greenhouse. Results showed that: (1) Both vermicompost and chicken manure compost showed significant positive effect on soil bacterial diversity and richness, while cow manure compost significantly decreased bacterial diversity and richness. (2) Compared with control, organic amendments increased the relative abundance of dominant bacteria Proteobacteria and Actinobacteria by 36.40%-44.27% and 25.80%-29.35%, respectively, but significantly decreased that of Acidobacteria. The highest relative abundances of Proteobacteria and Actinobacteria were found in rice straw and vermicompost treatments, respectively, whereas the lowest relative abundance of Acidobacteria was found in cow manure compost treatment. Organic amendment applications promoted the growth of beneficial bacteria (such as Sphingomonas, Gemmatimonas, Bacillus, Streptomyces and Porphyrobacter) and suppressed pathogen bacteria (such as Gp6, Gp16 and Gp4). (3) Compared with control, all the treatments significantly decreased soil pH, but significantly increased EC value. Results of Pearson’s correlation analysis revealed that Vermicompost soil NH₄⁺ content, EC, pH value, and total C content were the most dominant factors affecting bacterial community composition. In summary, our results indicated that vermicompost was better than other organic amendments in improving soil bacterial community structure. More attention should be paid on the use of vemicompost in sustainable production of tomato in greenhouse.

Key words: water-level-fluctuating zone, plant composition, dominant species, niche breadth, niche overlap