Free-living nematode associated with almond (Prunus Dolcis Mill.) orchards and the effect of soil chemical properties on their diversity

Abstract

Aim: Free-living nematodes are an important group for the soil biodiversity. Free-living can be classified as bacterivores, fungivores, omnivores, and predators and thus contribute to fundamental ecological processes in the soil, such as decomposition and nutrient cycling. Materials and Methods: Seven nematode species were identified from the soil samples during a survey on free-living nematodes in five almond (Prunus dolcis Mill.) orchards. The samples were collected across the orchards in the central part of Iran. Results: Out of the 15 soil samples collected in 2017, the most prevalent nematodes encountered were Cephalobus persegnis (2345), Butlerius butleri (560), and Panagrolaimus rigidus (230). The CCA results indicated that C. persegnis, B. butleri, and Mesorhabditisi sp. were more affected on K%, Ca%, Carbon%, Silt%, and Clay% found in Kharaji Teshneez orchards. However, P. rigidus, Aporcelaimellus sp., Prismatolaimus sp., and Geomonhystera sp. were dominant in substrates characterized by Na%, pH (KCl), Mg%, and Sand% in Saman, Chelvan, and ChamAli orchards. Conclusion: The diversity of free-living nematodes in Saman, ChamAli, and Chelvan was higher than in other orchard localities. Many free-living nematodes on the rhizosphere of almond tress may be due to the regular application of organic manure.