Effect of Soil Chemical Properties on the Occurrence and Distribution of Entomopathogenic Fungi in Portuguese Grapevine Fields.

Entomopathogenic fungi (EPF) contribute to different ecosystem services. However, factors affecting their natural occurrences in soil remain poorly understood. In a previous study, 81 soil samples were subjected to insect baiting using and to isolate EPF from Portuguese vine farms. Here, soils yielding any of the four common EPF, i.e., , , , and f. , were correlated with their chemical properties. was negatively affected by higher available P ( = 0.02), exchangeable K-ions ( = 0.016) and positively affected by higher soil pH_HO ( = 0.021). High exchangeable K-ions inhibited ( = 0.011) and promoted f. ( = 0.03). Moreover, high available K also suppressed ( = 0.027). was inhibited by higher organic matter content ( = 0.009), higher C:N ( = 0.017), total N ( = 0.007), and exchangeable Mg-ions ( = 0.026), and promoted by higher exchangeable Na-ions ( = 0.003). Nonetheless, mean comparisons and principal component analysis suggested that higher soil pH and exchangeable Ca-ions have contrasting effects on EPF occurrences, as they promote and inhibit . Herbicides did not seem to affect EPF presence. Overall, this study is among the first reports on the effects of soil chemistry on EPF other than , and will facilitate biological pest management approaches.