Cover cropping increases the abundance of mycorrhizal and endophytic fungi structures associated with ecosystem functioning

Soil is one of the most complex microbial environments on earth, providing many ecosystem services to benefit humankind. Many of the services associated with soil microorganisms are particularly important to the agricultural industry as these improve crop stress tolerance, nutrition, and yield. However, conventional agricultural practices that use excessive chemical inputs, tillage, and monocropping have diminished the soil biosphere and lessened the ecosystem services that microbes are able to provide. Cover cropping is one of the key principles underpinning conservation agriculture systems. Despite it being relatively well-known that cover cropping has a beneficial impact on the overall abundance and community structure of soil microbes, the effects on specific microbial structures and their functions are vastly under-researched. In fact, some fungal structures investigated in this study have never been examined under cover cropping systems before. Therefore, soil samples were taken from five cover cropped and five conventionally managed fields growing spring bean (Phaseolus vulgaris) in Kent, UK, and the abundance of seven key mycorrhizal and endophytic fungal structures were identified. Cover cropping was associated with a significantly higher abundance of hyphae, arbuscules, vesicles, moniliform hyphae, and microsclerotia, but not spores or chlamydospores. Since these structures are known to be associated with nutrient exchange, overwintering and long-term survival, energy storage, and branching and inoculation, cover cropping practices are likely to improve the functioning of mycorrhizal and endophytic fungi.