The researchers used geostatistics and GIS to study soil nutrients on Chongming island in China. They found that some nutrients like AK and CEC had moderate variability, while others like AN, TN, AP, and OM had strong variability. CEC showed little correlation, while TN had significant correlation. By using a multi-scale model, they were able to create maps showing how these nutrients are distributed across the island. The study also revealed that soil salinity influenced the fertility of the soil in different ways.