Crop rotations increased soil ecosystem multifunctionality by improving keystone taxa and soil properties in potatoes

Continuous cropping of potatoes leads to soil degradation, ecosystem multifunctionality reduction and potato production decline, and these impacts could be mitigated through rotation cropping. Although crop rotation promotes improvements in soil fertility, microbial community diversity, and potato yield, its effects on the soil ecosystem multifunctionality, keystone taxa, and their main drivers remain unclear. In the present research, we comparatively explored the effects of potato continuous cropping (PP) and rotation cropping (potato - oat rotation (PO) and potato - forage maize rotation (PFM)) on the soil ecosystem multifunctionality (EMF) as well as the roles of keystone taxa, microbes abundance, and chemistry properties in ecosystem multifunctionality improvement. It was demonstrated that soil ecosystem multifunctionality increased in rotation cropping (PO and PFM) over PP. Soil pH was higher in rotation cropping (PO and PFM) compared with PP, while total phosphorus (TP), available phosphorus (AP) were decreased significantly than that in PP. Rotation cropping (PO and PFM) markedly changed the bacterial and fungal community compositions, improved the beneficial fungi e.g. Schizothecium and Chaetomium, while reduced the abundances of the pathogenic fungi e.g. Altemaria, Fusarium, Verticillium dahiae, Gibberella, Plectosphaerella, Colletotrichum, Phoma, and Lectera compared with PP. Also, co - occurrence patterns for bacterial and fungal were apparently impacted by crop rotations, and keystone taxa e.g. Nitrospira.1, Lysinibacillus, Microlunatus.1, Sphingomonas.3, Bryobacter.1 and Micromonospora, Schizothecium were enriched in PO and PFM compared with PP. Structural equation model (SEM) further demonstrated that cropping systems increased soil ecosystem multifunctionality through regulating SOM and keystone taxa (Schizothecium1), and keystone taxa were obviously mediated by soil pH. This study suggested that rotation cropping might contribute to the improvement of soil ecosystem multifunctionality as well as the development of disease - suppressive soils compared with potato continuous cropping.