The characterization of the soil biological quality of organic viticulture can be achieved by analyzing soil nematofauna

Soil nematofauna is a bioindicator that can highlight changes in biological functioning when changing agricultural practices. In the present study, the effects of conversion of vineyards to organic agriculture on biological soil quality were evaluated. Twenty four conventional plots and organic plots in Cruscades (Aude) were studied: they were divided into four groups: (1) conventional, (2) converted for 7 years (Bio 7 years), (3) converted for 11 years (Bio 11) and (4) converted for 17 (Bio 17). The nematofauna was analyzed in 96 soil samples (four samples per plot) taken from the surface layer of soil (0-15 cm). The more longer the conversion of plots to organic viticulture, the higher the biological activity of the soil; it is the abundance of non-plant parasitic nematodes that gives this indication. The effects of conversion on soil biological functioning were significant relatively late (≥ 11 years) after the change of practices. Moreover, the study of the functional diversity of nematodes shows that the soil remained disturbed in the organic as in the conventional system (no increasing complexity of the soil food web measured by the structure index).