Identification of the distribution, contamination levels, sources, and ecological risks of heavy metals in vineyard soils in the main grape production area of China

We collect a total of 101 typical vineyard soil samples from the Turpan Basin, the main grape production area in China, and analyze their concentrations of six heavy metals: arsenic (As), cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb), and mercury (Hg). To estimate contamination and the potential ecological risk from heavy metals, we employ the pollution load index (PLI) and potential ecological risk index (RI), while we use, the geostatistical analysis to analyze spatial distribution patterns of heavy metals. Multivariate statistical analysis helps us to identify the main sources of heavy metal contamination, and the results we obtain indicate that the average concentrations of six metals in vineyard soils in the Turpan Basin are lower than the limits of the Soil Environmental Quality—Risk Control Standard for Soil Contamination of Agricultural Land (GB 15618—2018). However, the average concentrations of As, Cd, Cr, and Hg exceed the background values of agricultural soils in Xinjiang by factors of 1.05, 1.58, 1.49, and 1.15, respectively. We find the vineyard soils to be low contaminated by As, Cd, Cr, and Hg, and slightly contaminated by Ni and Pb. Furthermore, we find the spatial distribution patterns of the concentrations and contamination levels of the six heavy metals in vineyard soils to be substantially heterogeneous. Heavy metals in vineyard soil show a low ecological risk level, and Cd poses the most significant ecological risk among the investigated heavy metals. Cr and Ni in vineyard soils stem mainly from natural sources, whereas Cd and Pb mainly originate from anthropogenic sources. However, As and Hg come from by both natural and anthropogenic sources.