Communities of arbuscular mycorrhizal fungi (AMF) were studied in sod culture (SC), straw mulching (NM), and herbicide treated and no-tillage (NH) citrus orchards, respectively. The highest total colonization rate (39.47%) and hyphal length density (1.15 m/g soil) were found in SC, the highest spore numbers (1024 spores/100 g soil) in NM, while the lowest ones (31.50%, 0.94 m/g soil and 719 spores/100 g soil) in NH and they varied significantly among three different types of orchards. Total 18 AMF species belonging to five families, Acaulosporaceae (four species), Claroideoglomeraceae (two species), Gigasporaceae (one species), Glomeraceae (nine species) and Pacisporaceae (two species) were identified, and Glomus aggregatum and Claroideoglomus etunicatum were the dominant species in all surveyed plots. The redundancy analysis showed that AMF community structure was influenced greatly by pH, soil management, soil organic matter (C ox) and available phosphorus (P Olsen). In SC orchards, species richness and Shannon-Wiener index of AMF were notably higher than in other treated orchards. So, it is reasonable to select SC as the best practice in citrus orchard in order to enhance AMF benefits.
