A recent study (Rinaudo et al., 2010) indicated a secondary benefit of arbuscular mycorrhizal fungi (AMF) – to suppress growth of significant agricultural weeds (Chenopodium album and Echinocloa crus-galli). Weeds can be used as indicators of soil depletion or imbalance. They also provide beneficial services to an organic garden. It may be that understanding which weeds are useful and inoculating your garden plot with AMF may increase the biodiversity necessary to create a self-sustaining ecology.
Still, the results of the paper cited above don’t clarify the mechanism for weed suppression. Known for increasing plant root phosphorous uptake, did the presence of AMF in the soil alter phosphorus availability in general or bring deeper lying phosphorous stores up to plant root systems?
Rinaudo, V., Barberi, P., Giovannetti, M. and van der Heijden, M.G.A. 2010. Mycorrhizal fungi suppress aggressive agricultural weeds. Plant and Soil 333: 7-20.