Response of nematode community structure to different restoration practices in two vineyard soils in Tuscany (Italy)

Inappropriate land preparation before vineyard establishment can lead to soil degradation and vine health issues, with consequent reductions in the quantity and quality of the grapes. In the present short-term trial, the effects of dry mulching, green manure and compost treatments were evaluated as restoration strategies to enhance soil functionality in degraded vineyard areas at two Tuscan farms that had been under organic management for different lengths of time. Soil nematode community, soil physical and chemical properties were monitored as indicators of soil quality. The restoration treatments scarcely affected soil chemical or physical qualities; only the compost application increased soil total organic carbon (TOC). Bacterial feeder nematodes increased under dry mulching in response to the organic carbon inputs on the farm in conversion. Plant-parasitic nematodes decreased only after the first year of the restoration treatments and predators decreased during all 3 years. Nematode indicators showed only a few differences between the different management regimes; the diversity weighted abundance expressed as biomass indicated that the restoration practices sometimes represented a disturbing factor in ecosystem services regulation. The abundance of nematode taxa was differently affected by soil physico-chemical properties. On the farm that had been managed organically for longer, the higher proportion of large sized stable aggregates and greater soil porosity benefitted large nematodes such as predators, while the higher moisture levels were unfavourable for some plant-parasitic nematodes. However, on the farm still in conversion, increases in TOC and C/N ratio values were associated with a reduction in plant-parasitic nematodes.