High phosphorus availability promotes the diversity of arbuscular mycorrhizal spores’ community in different tropical crop systems

We aimed to evaluate the effects of tropical crop systems and phosphorus (P) availability on arbuscular mycorrhizal fungi (AMF) spores’ community composition, and soil chemical properties in a Planosol at Tropical ecosystem from Brazilian Northeast. We collected rhizospheric samples containing soil and root fragments in a 5-year field experiment considering two groups of crop systems, i.e., no-till monocropping and agroforestry system, and testing two factors: the cropping system and the soil P availability. We identified the AMF community composition based on AMF spore’s morphology. We also characterized the soil chemical properties (e.g., soil pH, soil organic carbon, and available P) at samples level. Crop systems and soil P availability influenced the AMF community composition, and soil chemical properties. We found that: i) the abundance of Claroideoglomus claroideum , C. etunicatum , Rhizophagus intraradices , richness, Shannon’s index and Simpson’s index were positively correlated with no-till monocropping systems ( Arachis hypogaea , Gossypium hirsutum , and Vigna unguiculata ) and with all the studied agroforestry systems at low-P availability; and ii) soil pH, and soil organic carbon were positively correlated with no-till monocropping systems ( Arachis hypogaea , Glicine hirsutum , Glicine max , and Sesamum indicum ) at high-P availability, and Glicine max , Sesamum indicum , Zea mays , and agroforestry system at low-P availability. Our results highlight the positive effect of high P on AMF spores’ diversity, and the importance to consider both the crop system and soil P availability as key-factors promoting shifts into the AMF community composition and soil chemical properties in Tropical conditions.