Thirty-year dryland crop rotation improves soil multifunctionality and shifts soil fungal community

Crop rotation plays an important role in changing soil microbial communities, which is critical to maintaining soil multifunctionality. However, limited data exist on the long term impact of crop rotations on soil multifunctionality and its link with soil fungal community in drylands. In a dryland field experiment with 30-year legume- and non-legume-based winter wheat rotations and winter wheat-fallow system, we investigated the soil multifunctionality (via cycling and pools of soil carbon and nitrogen) and the overall community and functional groups of soil fungi. The links between soil multifunctionality and fungal communities were also explored. We found that long-term crop rotation increased soil multifunctionality index and that of carbon cycle. Crop rotation shifted soil fungal community composition, and reduced the proportion of putative pathotrophs. The overall fungal community was almost equally explained by soil and plant variables, while fungal functional groups (i.e., saprotrophs and pathotrophs) were more affected by soil variables. The indicator taxa in the non-legume-winter wheat rotation were distinctly different from those in the legume-based winter wheat rotation soils, indicating that the non-legume-winter wheat rotation selects different fungal taxa from the legume-based winter wheat rotation. Moreover, the changes in community composition of soil fungi, putative saprotrophs and pathotrophs were related to soil multifunctionality and that of carbon and nitrogen cycles. Our results highlight that long-term crop rotations shape the soil fungal communities; the changes in soil fungi and fungal functional groups have potential to improve soil multifunctionality in the crop rotation systems in drylands.