[Optimization and Application of Soil Health Evaluation Method for Edible Beans]

Edible beans play a significant role in healthy dietary structures， human health， and soil improvement. Scientifically and reasonably assessing the health status of the soil where they are cultivated is crucial for achieving green， high-yield， and high-quality production. This study focused on soils from major edible bean-producing areas across the country， collecting soil samples from 0-20 cm depth and measuring 27 indicators reflecting soil physical， chemical， and biological characteristics. Principal component analysis （PCA） and network analysis （NWA） were used to obtain the minimum data set， combined with linear scoring （L） and nonlinear scoring （NL） standardization methods， as well as the integrated health index （IHI） and Nemerow quality index （NQI） integration methods， to construct eight soil health assessment methods and calculate the corresponding soil health index （SHI）. By comparing the SHI constructed from the full dataset through correlation and sensitivity analyses and combining the linear fitting results of SHI with soil organic carbon （SOC） and yield， the most suitable soil health assessment method for the major edible bean-producing areas was selected， and the soil health status was evaluated. The results indicated： ① The four SHIs （L-IHI， NL-IHI， L-NQI， and NL-NQI） based on the minimum data set obtained by NWA showed a higher correlation （r>0.8） with the SHI constructed from the full dataset than those based on PCA （0.6<r<0.8）， better reflecting overall soil health status. ② The variation degree of the four SHIs based on NWA （60%-70%） was much higher than that of the SHI constructed from the full dataset and PCA （20%-40%）， indicating higher sensitivity for evaluating soil health in major edible bean-producing areas nationwide. ③ Among the four SHIs based on NWA， L-IHI showed the best linear fitting results with yield and SOC， indicating that NWA-L-IHI is the optimal method for evaluating soil health in major edible bean-producing areas. ④ According to the NWA-L-IHI method for evaluating soil health in major edible bean-producing areas nationwide， the results showed that the soil health level in subtropical and warm temperate regions was generally higher than that in mid-temperate regions. The soil health level in major producing areas in Yunnan and Fujian provinces was relatively high （SHI>0.2）， whereas the soil health status in major producing areas in Shaanxi， Shanxi， Hebei， and Inner Mongolia provinces （autonomous regions） was relatively poor （0.05<SHI<0.15）. The study results clarified the soil health status in different regions， providing a scientific basis for soil management. Appropriate nutrient management， such as fertilization and providing organic cover， can address the deficiency of nitrogen， phosphorus， and micronutrients， and each province can also improve soil health by exploring locally suitable edible bean planting patterns.