Sugarcane-peanut intercropping stimulatory effects on arbuscular mycorrhizal and entomopathogenic fungi promote soil health and crop productivity

Context: Most short-term in vitro studies conducted in a single season and location have highlighted the sup-pressive effect of entomopathogenic fungi (EPF) and arbuscular mycorrhizal fungi (AMF) on insect pests. However, little is known about AMF and EPF response to sugarcane-peanut intercropping and how sugarcane-peanut intercropping suppressive effects mitigate pathogenic fungi and promote crop productivity at different time points and locations.Objective: Here, we explored the response of AMF and EPF communities and functions to sugarcane-peanut intercropping and the roles sugarcane-peanut intercropping play in promoting crop growth and yield. We also evaluated sugarcane-peanut intercropping suppressive effects on pathogenic fungi and deciphered the associa-tion between fungi community structure and soil chemical properties. Methods: Sugarcane-peanut intercropping was conducted in two locations in July and November. Rhizosphere and non-rhizosphere soils of the two locations were sampled and investigated using ITS high-throughput sequencing.Results: We observed that sugarcane-peanut intercropping boosted the sugarcane diameter and peanut yield. Moreover, sugarcane-peanut intercropping promoted soil available potassium (AK) and available nitrogen (AN) in July, while soil AK, available phosphorus (AP), organic matter (OM), and potential hydrogen (pH) peaked in November, especially in the rhizosphere. The intercropping rhizosphere soils enriched EPF, including Clonos-tachys in July, followed by Beauveria and Arthrobotry in both July and November, especially in location B. Moreover, Metarhizium in the bulk soil of location A also responded strongly to sugarcane-peanut intercropping in November. Similarly, AMF such as Rhizophagus performed better in the intercropping rhizosphere soil in lo-cations A and B, especially in July. We believed this phenomenon was crucial in suppressing pathogenic fungi, including Alternaria, Fusarium, and Exserohilum. Additionally, the enrichment of AMF and EPF also explains the increase in soil nutrients and crop productivity, which was reinforced by the patterns observed in fungi func-tional analysis, where fungi function associated with AMF and EPF detected in November outperformed those identified in July in both locations.Conclusions: Taken together, our findings provide inclusive empirical evidence of how sugarcane-peanut inter-cropping promoted AMF and EPF, which, in turn, suppressed the presence of pathogenic fungi, thereby pro-moting a favorable condition for the sugarcane-peanut growth and yield. Implications: Sugarcane-peanut intercropping system is a promising alternative to synthetic inputs that provides biological protection for plants against pathogenic fungi by promoting AMF and EPF in different sugarcane cropping seasons.