18S rRNA gene of arbuscular mycorrhizal fungi. Arbuscular mycorrhizal fungi (AMF) are ubiquitous soil microorganisms which form a mutualistic symbiosis with the roots of over 80% of all land plants. They are beneficial for agricultural crop productivity, because they improve plant nutrition acquisition by supplying mineral nutrients. Furthermore, AMF community is one of good indicators of soil ecosystem. Therefore, we postulate that the knowledge of AMF diversity responses to different fertilizations could help to direct us towards a more effective fertilization. For such purpose, AMF assemblages in arable soils with over 20-year different fertilizations (organic manure, fertilizer NP, NK and NPK as well as control without fertilization) were investigated. The sequence data set allow us to make exhaustive analyses and comparisons of AMF community structures, richness and diversities under different long-term fertilizations, and are of great help towards a better understanding of the effective fertilization.