A Systematic Review of Arbuscular Mycorrhizal Fungi Colonization and Richness Under Conventional and Organic Management in Agriculture.

A systematic review of arbuscular mycorrhizal fungi colonization and richness under conventional and organic management in agriculture
Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with most land plant roots, these symbioses play an important role in plant growth and productivity. The ocurrence of AMF and the establishment of mycorrhiza depend, besides on the host plant, on soil properties and management. Several studies have evaluated the effect of chemical and organic inputs on AMF in agricultural systems and have confirmed that organic fertilization affects mycorrhization. Some of them have proposed AMF as soil quality indicators. The aim of this study was to analyze the variation of mycorrhization and Glomeromycota richness under conventional and organic inputs in different crops. We reviewed papers between 1992 and 2015 and we found that mycorrhization varied in crops under different agricultural inputs. 56% of the reviewed papers presented higher values for mycorrhization under organic inputs while 12% reported lower values in those systems. In spite of no consensus was found for richness, almost 40% of papers showed that richness increases when manures are applied to the soil. We conducted a meta-analysis to assess differences between chemical and organic fertilizers in AMF colonization. Our results suggested that mycorrhization is a soil sensitive indicator that must be included among biological soil quality parameters.