Soil Health Assessment in the Qinling Reclamation Area Based on Minimum Data Set and Risk Index

［Objective］ To explore the impact of different vegetation types on soil health in the Qinling region, to assess the relationship between aboveground plants and soil health, and construct a comprehensive soil quality health evaluation model. ［Methods］ Five vegetation types were selected, including poplar forest (RY), pine forest (RP), mixed forest (RM), privet forest (RL), and vineyard (CK). Soil samples were collected from different depths (0~20 cm and 20~40 cm), and the analysis was conducted using the Minimum Data Set (MDS) method combined with 35 soil physical, chemical, and biological indicators, along with the contents of four heavy metals. ［Results］ 1) The Minimum Data Set (MDS) was established for soil fertility evaluation, eight biological and non-biological indicators were included, i.e., field moisture capacity (FMC), physical clay content, pH, soil organic carbon (SOC), microbiological total PLFA, eukaryotic microbial PLFA, nitrogen acquisition enzyme (NAG), and microbial biomass nitrogen (MBN). Potential Ecological Risk Index (RI) was used to assess the pollution risk of four heavy metals for soil environmental risk evaluation. Soil health was assessed by combining MDS and RI. 2) Soil fertility of RY was significantly higher than that of RP and RM. The lower SOC, NAG, FMC, and eukaryote significantly limited soil fertility, while the higher heavy metal pollution risk in CK severely restricted its soil health rating. 3) There were significant differences in soil health at different depths, indicating that the diversity of surface herbaceous plants increased soil fertility and reduced heavy metal pollution, significantly impacted soil health. ［Conclusion］ Reasonable reclamation measures and increased diversity of surface vegetation can significantly improve soil health. The restoration of reclamation vegetation can help improve soil fertility and reduce heavy metal pollution. It is recommended to strengthen the diversity of herbaceous plants in future reclamation processes and increase fertilization to improve soil ecosystem functions and health levels.