Influence of organic farming on arbuscular mycorrhizal fungal populations in a Mediterranean agro-ecosystem

Arbuscular mycorrhizal fungi (AMF) are key components of the soil microbiota, fundamental for soil fertility, plant nutrition and functioning of agroecosystems. Data on the interactions between organic practices and AMF populations are limited and inconsistent. Here we compared AM fungal communities and glomalin-related soil protein (GRSP) content occurring in a recently converted organically farmed soil with those occurring in a conventionally managed soil. The results show that the two farming systems did not significantly differ in AM fungal spore populations and glomalin-related soil protein. We hypothesize that in our experimental system, which was converted from conventional to organic farming only recently (5 years), there may not have been enough time to allow the establishment of differentiated AM fungal populations.