Arbuscular Micorrizal Fungi and Farm Management Practices

Arbuscular mycorrhizal fungi (AMF) are commonly present in most tropical land ecosystems; however, high rates of fertilization can disrupt their life cycle. The AMF occurrence in different crop systems compared to native vegetation in tropical conditions is not well understood. With the aim to analyze potentially benefic symbionts for crop production in an experimental farm, the AMF community structure along different crop cultivation was investigated. Soil subsamples were used to inoculate trap cultures using Sorghum sp. as host. The preserved unfertilized area showed a greater diversity of AMF, followed by the grassland and sugarcane. Number of AMF spores was also greater in the preserved area (47 spores per 100g soil) than the numbers estimated for other sites. Nine AMF genera of Glomeromycotina (spores) and 16 AMF species were observed in the native forest. The natural richness appears to be favored when Sugarcane or grasses are planted; however, the preserved native forest showed unique characteristics. Soils under native forest stored higher amount of SOM, presented higher macro-aggregates and preserved more charcoal than the samples of permanent grassland or under maize. The maize associated AMF community diverged from grassland, as described by the principal component analysis. This study showed differences in AMF communities from cultivated plots compared to native vegetation as well as potential for inoculant formulation for economically crops.

Keywords: Arbuscular mycorrhizal fungi; Atlantic Forest; Sugarcane; Maize; Grassland