Landscapes, management practices and their interactions shape soil fungal diversity in arable fields – Evidence from a nationwide farmers' network

Abstract

Fungi influence agricultural production due to their key roles in soil biotic and abiotic processes. However, there is limited knowledge of their status at scales relevant for farm management and policymaking. We examined the relationships between commonly applied agricultural practices and soil fungal diversity in 78 arable fields in Estonia. We used DNA metabarcoding of the ITS and SSU regions to detect soil total, arbuscular mycorrhizal, pathogenic and saprotrophic fungal diversity. We also collected field management data and assessed the proportion of field area influenced by uncropped landscape elements. We found that fertilizer type and pesticide use frequency, but not tillage regime, were important determinants of soil fungal diversity in fields. We also found that soil fungal richness was generally higher when a larger proportion of the field was influenced by uncropped landscape elements. Importantly, we found significant interactions between fertilization type and frequency of pesticide use, which, in some cases, resulted in amplified negative effects on soil fungal species richness. Our work highlights the need for simultaneous assessment of multiple landscape and management impacts on soil biota.