Arbuscular mycorrhizal symbiosis increases P uptake and productivity of mixtures of maize varieties compared to monocultures

Ecological intensification seeks to achieve crop yield increases through intensifying complementary or facilitative interactions between plant species or varieties. Different species of arbuscular mycorrhizal fungi (AMF) exhibit niche differentiation and show selectivity towards certain plants, which can further enhance complementarity. It is not clear whether in the presence of one AMF species, where mycelial networks connect crop species, opportunities for complementarity effects may be reduced. We grew monocultures and mixtures of maize varieties in a greenhouse with one species of AMF, Funneliformis mosseae, during two consecutive years to investigate whether under such conditions the mycorrhizal symbiosis would affect complementarity and overyielding compared to non-mycorrhizal plants. Variety mixtures showed increased phosphatase activity and mycorrhizal colonization, enhanced P-uptake and overyielding when plants were mycorrhizal. There was no overyielding when plants were ...