The quality and yield of ginseng are significantly affected by ecological factors, especially soil, which is a complex environment. This study compared the quality, yield, and soil differences of ginseng in a Mongolian oak forest (MOFG), birch forest (BFG), mixed wood forest (MWFG), poplar forest (PFG), farmland (FlG), and a felling forest (DfG). Based on these differences, the relationship between the three was explored, as was the most suitable forest type for developing understory ginseng cultivation. The soil bacteria diversity of DfG was similar to that of understory ginseng, and its ginsenoside content was at the same level as that of understory ginseng. The soil pH of FlG was significantly lower than that of the other five cultivation methods, and the soil bacteria were also different from them, especially those related to the nitrogen cycle. Ginsenoside Rg2 has a significant correlation with many soil factors and is sensitive to soil environmental differences. In conclusion, there were significant differences in the quality, yield, and soil environments between the different planting methods. MOFG was the most suitable for planting with excellent quality and high yield, while BFG was the worst; as such, planting in BFG should be avoided.

Soil, as the foundation for the survival of understory ginseng, directly impacts its growth and development. However, studies focusing on the role of soil in determining the quality of understory ginseng are limited. This study examines the relationship between quality and yield of 5-, 9-, and 17-year-old understory ginseng and their soil microbiota. The results indicate that with the increase in growth years, the overall biomass of understory ginseng generally shows an upward trend, while its quality slightly decreases at 9 years. Compared to the other two growth years, the soil from 9-year-old ginseng shows lower enzyme activity and pH and a higher abundance of pathogens. The 17 years soil has higher OM and AHN content, along with increased abundance of denitrifying and nitrogen-reducing bacteria. Correlation networks reveal that AK significantly influences ginsenoside content, while AP and AHN are more closely related to soil microorganisms. Compared with other types of ginsenosides, ginsenosides Rh2 and Rd are affected by a greater variety of soil microorganisms and chemical factors. As growth years increase, the changes in ginseng quality, soil nutrients, and soil microbiota do not follow a single linear trend; instead, there appears to be a bottleneck phase at certain intermediate stages.