Copper concentration in the vineyard and forest topsoils. A comparative study with individual pollution indices

The study objectives were to evaluate the soil pollution with Copper (Cu) for different land uses, namely the cultivated and abandoned vineyards, the stripped soil from the abandoned vineyard, and the topsoil under forest vegetation, using individual pollution indices. Soil samples were systematically collected from the A horizon in both cultivated and abandoned vineyards, and from the local forest, and from three soil profiles. To assess the soil quality, the Enrichment Factor (EF), Geoaccumulation Index (Igeo), and Pollution Index (PI) were calculated based on values obtained from soil sample analysis and various thresholds or guideline values. The individual pollution indices reveal the following sequence for Cu concentration: stripped soil in the abandoned vineyard > soil in the abandoned vineyard > soil in the cultivated vineyard > soil in the forest. When using Romanian or Finnish standards, the PI shows more variability than EF and Igeo indices, leading to different soil contamination classifications. Indices based on conservative elements and local geochemical background provide more stable results, especially for cultivated soils. The volume of treatments applied can explain the higher concentration of Cu in the abandoned vineyard compared to the cultivated one (ampelographic collection). The Specific Pollution Index provides a two-dimensional assessment of pollution through the difference in Cu concentration in the upper part of the soil in two ecosystems (viticulture and forestry), adjusted to the content of the same element in the local geochemical background.