A survey in sunflower fields in Tekirdağ, Türkiye to determine soil health with nematode-based diversity indices

Abstract

In this study conducted in 2021-2022, nematode community structure was investigated in sunflower fields in Tekirdağ to determine sampled fields' physical characteristics based on nematode biodiversity indices. For this purpose, soils collected from 37 sunflower fields were examined for nematode presence. In the soils, 34 genera of fungivore [3 genera, e.g., Aphelenchoides Fischer, 1894 (Aphelenchida: Aphelenchoididae)], bacterivore [9 genera, e.g., Acrobeloides Cobb, 1924 (Rhabditida: Cephalobidae)], omnivore [4 genera, e.g., Dorylaimus Dujardin, 1845 (Dorylaimida: Dorylaimidae)], predator [2 genera, e.g., Seinura Fuchs, 1931 (Aphelenchida: Aphelenchoididae)], and plant-parasitic [17 genera, e.g., Pratylenchus Filipjev, 1936 (Tylenchida: Pratylenchidae)] nematodes were recovered by the modified Baermann Funnel method. The dominant nematodes were fungivores and plant-parasitics occurring in all fields. Among 17 plant-parasitic nematodes identified at a species level, the most economically important species were Longidorus elongatus Mikoletzky, 1922 (Dorylaimida: Longidoridae), Ditylenchus dipsaci (Kühn, 1857) Filipjev,1936 (Tylenchida: Anguinidae), Pratylenchus thornei Sher & Allen 1953, and Pratylenchus zea Graham, 1951 (Tylenchida: Pratylenchidae). Maturity indices calculated to estimate soil characteristics in fields were 2.33±0.36, and the value was determined to be <3 in most fields except for two fields. Food web analysis revealed that 76.3% of soils had worsened physical characteristics and a high C: N ratio. The characteristics of soils in two fields were enriched, and the others were fertile.