Soil geochemical baseline values and background values in Xunke Plain of HeiLongJiang Province

Using geochemical data obtained from black soil quality surveys, this study investigates the geochemical baseline values and background values of soil in the northernmost Xunke Plain of China, as well as their differences from the national and Songliao Plain soil baseline values and background values. This provides a reference basis for studying soil baseline values and background values in different climates and geographical environments, and has reference significance for enriching the study of soil geochemical characteristics in different regions of China. By comparing the geochemical background values of elements with the baseline values, it was found that among the 54 analyzed indicators, 41 elements or indicator soil background values were equivalent to the baseline values, indicating that the vast majority of elements in the surface soil inherited the level of parent material content, and the influence of soil formation and human activities on the enrichment or depletion of surface soil elements was relatively small. Nine elemental indicators, including Cl, Mn, P, I, S, Br, N, TC, and Corg, were significantly enriched in the surface soil; Cd and Ag are locally enriched due to mining activities; The significant depletion of Au and Hg elements indicates that these elements are greatly influenced by epigenetic processes and human activities. Compared with the background values in other regions, the soil nutrient indicators N, P, TC, and Corg in the Xunke Plain are significantly higher than those in the national soil and Songliao Plain soil background values, indicating that the soil in the Xunke Plain is fertile and high-quality black soil resources. However, there is also a risk of heavy metal pollution in some areas, and attention should be paid to protection and utilization.